<?php

/* $Id: phplot.php,v 1.3 2008/07/25 15:14:32 wolff_borg Exp $ */

/*
 * PHPLOT Version 5.0.rc1
 * Copyright (C) 1998, 1999, 2000, 2001 Afan Ottenheimer.  Released under
 * the GPL and PHP licenses as stated in the the README file which should
 * have been included with this document.
 *
 * Recent (2003-2004) work by Miguel de Benito Delgado <nonick AT vodafone DOT es>
 *
 * Requires PHP 4.2.0 or later (CHECK THIS)
 */

if (! defined(__FUNCTION__))
    define(__FUNCTION__, '__FUNCTION__ Requires at least PHP 4.3.0.');

define ('MINY', -1);        // Indexes in $data (for DrawXDataLine())
define ('MAXY', -2);
define ('TOTY', -3);

error_reporting(E_ALL);

class PHPlot {

    /* I have removed internal variable declarations, some isset() checking was required,
     * but now the variables left are those which can be tweaked by the user. This is intended to
     * be the first step towards moving most of the Set...() methods into a subclass which will be
     * used only when strictly necessary. Many users will be able to put default values here in the
     * class and thus avoid memory overhead and reduce parsing times.
     */
    //////////////// CONFIG PARAMETERS //////////////////////

    var $is_inline = FALSE;             // FALSE = Sends headers, TRUE = sends just raw image data
    var $browser_cache = FALSE;         // FALSE = Sends headers for browser to not cache the image,
                                        // (only if is_inline = FALSE also)

    var $safe_margin = 5;               // Extra margin used in several places. In pixels

    var $x_axis_position = '';          // Where to draw both axis (world coordinates),
    var $y_axis_position = '';          // leave blank for X axis at 0 and Y axis at left of plot.

    var $xscale_type = 'linear';        // linear, log
    var $yscale_type = 'linear';

//Fonts
    var $use_ttf  = FALSE;                  // Use True Type Fonts?
    var $ttf_path = '.';                    // Default path to look in for TT Fonts.
    var $default_ttfont = 'benjamingothic.ttf';
    var $line_spacing = 4;                  // Pixels between lines.

    // Font angles: 0 or 90 degrees for fixed fonts, any for TTF
    var $x_label_angle = 0;                 // For labels on X axis (tick and data)
    var $y_label_angle = 0;                 // For labels on Y axis (tick and data)
    var $x_title_angle = 0;                 // Don't change this if you don't want to screw things up!
    var $y_title_angle = 90;                // Nor this.
    var $title_angle = 0;                   // Or this.

//Formats
    var $file_format = 'png';
    var $output_file = '';                  // For output to a file instead of stdout

//Data
    var $data_type = 'text-data';           // text-data, data-data-error, data-data, text-data-single
    var $plot_type= 'linepoints';           // bars, lines, linepoints, area, points, pie, thinbarline, squared

    var $label_scale_position = 0.5;        // Shifts data labes in pie charts. 1 = top, 0 = bottom
    var $group_frac_width = 0.7;            // value from 0 to 1 = width of bar groups
    var $bar_width_adjust = 1;              // 1 = bars of normal width, must be > 0

    var $y_precision = 1;
    var $x_precision = 1;

    var $data_units_text = '';              // Units text for 'data' labels (i.e: '¤', '$', etc.)

// Titles
    var $title_txt = '';

    var $x_title_txt = '';
    var $x_title_pos = 'plotdown';          // plotdown, plotup, both, none

    var $y_title_txt = '';
    var $y_title_pos = 'plotleft';          // plotleft, plotright, both, none


//Labels
    // There are two types of labels in PHPlot:
    //    Tick labels: they follow the grid, next to ticks in axis.   (DONE)
    //                 they are drawn at grid drawing time, by DrawXTicks() and DrawYTicks()
    //    Data labels: they follow the data points, and can be placed on the axis or the plot (x/y)  (TODO)
    //                 they are drawn at graph plotting time, by Draw*DataLabel(), called by DrawLines(), etc.
    //                 Draw*DataLabel() also draws H/V lines to datapoints depending on draw_*_data_label_lines

    // Tick Labels
    var $x_tick_label_pos = 'plotdown';     // plotdown, plotup, both, xaxis, none
    var $y_tick_label_pos = 'plotleft';     // plotleft, plotright, both, yaxis, none

    // Data Labels:
    var $x_data_label_pos = 'plotdown';     // plotdown, plotup, both, plot, all, none
    var $y_data_label_pos = 'plotleft';     // plotleft, plotright, both, plot, all, none

    var $draw_x_data_label_lines = FALSE;   // Draw a line from the data point to the axis?
    var $draw_y_data_label_lines = FALSE;   // TODO

    // Label types: (for tick, data and plot labels)
    var $x_label_type = '';                 // data, time. Leave blank for no formatting.
    var $y_label_type = '';                 // data, time. Leave blank for no formatting.
    var $x_time_format = '%H:%m:%s';        // See http://www.php.net/manual/html/function.strftime.html
    var $y_time_format = '%H:%m:%s';        // SetYTimeFormat() too...

    // Skipping labels
    var $x_label_inc = 1;                   // Draw a label every this many (1 = all) (TODO)
    var $y_label_inc = 1;
    var $_x_label_cnt = 0;                  // internal count FIXME: work in progress

    // Legend
    var $legend = '';                       // An array with legend titles
    var $legend_x_pos = '';
    var $legend_y_pos = '';


//Ticks
    var $x_tick_length = 5;                 // tick length in pixels for upper/lower axis
    var $y_tick_length = 5;                 // tick length in pixels for left/right axis

    var $x_tick_cross = 3;                  // ticks cross x axis this many pixels
    var $y_tick_cross = 3;                  // ticks cross y axis this many pixels

    var $x_tick_pos = 'plotdown';           // plotdown, plotup, both, xaxis, none
    var $y_tick_pos = 'plotleft';           // plotright, plotleft, both, yaxis, none

    var $num_x_ticks = '';
    var $num_y_ticks = '';

    var $x_tick_inc = '';                   // Set num_x_ticks or x_tick_inc, not both.
    var $y_tick_inc = '';                   // Set num_y_ticks or y_tick_inc, not both.

    var $skip_top_tick = FALSE;
    var $skip_bottom_tick = FALSE;
    var $skip_left_tick = FALSE;
    var $skip_right_tick = FALSE;

//Grid Formatting
    var $draw_x_grid = FALSE;
    var $draw_y_grid = TRUE;

    var $dashed_grid = TRUE;
    var $grid_at_foreground = FALSE;        // Chooses whether to draw the grid below or above the graph

//Colors and styles       (all colors can be array (R,G,B) or named color)
    var $color_array = 'small';             // 'small', 'large' or array (define your own colors)
                                            // See rgb.inc.php and SetRGBArray()
    var $i_border = array(194, 194, 194);
    var $plot_bg_color = 'white';
    var $bg_color = 'white';
    var $label_color = 'black';
    var $text_color = 'black';
    var $grid_color = 'black';
    var $light_grid_color = 'gray';
    var $tick_color = 'black';
    var $title_color = 'black';
    var $data_colors = array('blue','green','yellow','orange','red','purple','navy','SlateBlue','DarkGreen','tan','maroon','magenta','azure1','aquamarine1');
    var $error_bar_colors = array('blue','green','yellow','orange','red','purple','navy','SlateBlue','DarkGreen','tan','maroon','magenta','azure1','aquamarine1');
    var $data_border_colors = array('gray');

                

    var $line_widths = 1;                  // single value or array
    var $line_styles = array('solid', 'solid', 'dashed');   // single value or array
    var $dashed_style = '2-4';              // colored dots-transparent dots

    var $point_sizes = array(5,5,3);         // single value or array
    var $point_shapes = array('diamond');   // rect, circle, diamond, triangle, dot, line, halfline, cross

    var $error_bar_size = 5;                // right and left size of tee
    var $error_bar_shape = 'tee';           // 'tee' or 'line'
    var $error_bar_line_width = 1;          // single value (or array TODO)

    var $plot_border_type = 'sides';        // left, sides, none, full
    var $image_border_type = 'none';        // 'raised', 'plain', 'none'

    var $shading = 5;                       // 0 for no shading, > 0 is size of shadows in pixels

    var $draw_plot_area_background = FALSE;
    var $draw_broken_lines = FALSE;          // Tells not to draw lines for missing Y data.


//////////////////////////////////////////////////////
//BEGIN CODE
//////////////////////////////////////////////////////

    /*!
     * Constructor: Setup img resource, colors and size of the image, and font sizes.
     *
     * \param which_width       int    Image width in pixels.
     * \param which_height      int    Image height in pixels.
     * \param which_output_file string Filename for output.
     * \param which_input_fule  string Path to a file to be used as background.
     */
    function PHPlot($which_width=600, $which_height=400, $which_output_file=NULL, $which_input_file=NULL)
    {
        /*
         * Please see http://www.php.net/register_shutdown_function
         * PLEASE NOTE: register_shutdown_function() will take a copy of the object rather than a reference
         * so we put an ampersand. However, the function registered will work on the object as it
         * was upon registration. To solve this, one of two methods can be used:
         *      $obj = new object();
         *      register_shutdown_function(array(&$obj,'shutdown'));
         * OR
         *      $obj = &new object();
         * HOWEVER, as the second statement assigns $obj a reference to the current object, it might be that
         * several instances mess things up... (CHECK THIS)
         *
         * AND
         *    as $this->img is set upon construction of the object, problems will not arise for us (for the
         *    moment maybe, so I put all this here just in case)
         */
        register_shutdown_function(array(&$this, '_PHPlot'));

        $this->SetRGBArray($this->color_array);

        $this->background_done = FALSE;     // Set to TRUE after background image is drawn once

        if ($which_output_file)
            $this->SetOutputFile($which_output_file);

        if ($which_input_file)
            $this->SetInputFile($which_input_file);
        else {
            $this->image_width = $which_width;
            $this->image_height = $which_height;

            $this->img = ImageCreate($this->image_width, $this->image_height);
            if (! $this->img)
                $this->PrintError('PHPlot(): Could not create image resource.');

        }

        $this->SetDefaultStyles();
        $this->SetDefaultFonts();

        $this->SetTitle('');
        $this->SetXTitle('');
        $this->SetYTitle('');

        $this->print_image = TRUE;      // Use for multiple plots per image (TODO: automatic)
    }

    /*!
     * Destructor. Image resources not deallocated can be memory hogs, I think
     * it is safer to automatically call imagedestroy upon script termination than
     * do it ourselves.
     * See notes in the constructor code.
     */
    function _PHPlot ()
    {
        ImageDestroy($this->img);
        return;
    }


/////////////////////////////////////////////
//////////////                         COLORS
/////////////////////////////////////////////

    /*!
     * Returns an index to a color passed in as anything (string, hex, rgb)
     *
     * \param which_color * Color (can be '#AABBCC', 'Colorname', or array(r,g,b))
     */
    function SetIndexColor($which_color) 
    {
        list ($r, $g, $b) = $this->SetRGBColor($which_color);  //Translate to RGB
        $index = ImageColorExact($this->img, $r, $g, $b);
        if ($index == -1) {
            return ImageColorResolve($this->img, $r, $g, $b);
        } else {
            return $index;
        }
    }


    /*!
     * Returns an index to a slightly darker color than the one requested. 
     */
    function SetIndexDarkColor($which_color) 
    {
        list ($r, $g, $b) = $this->SetRGBColor($which_color);

        $r -= 0x30;     $r = ($r < 0) ? 0 : $r;
        $g -= 0x30;     $g = ($g < 0) ? 0 : $g;
        $b -= 0x30;     $b = ($b < 0) ? 0 : $b;

        $index = ImageColorExact($this->img, $r, $g, $b);
        if ($index == -1) {
            return ImageColorResolve($this->img, $r, $g, $b);
        } else {
            return $index;
        }
    }

    /*!
     * Sets/reverts all colors and styles to their defaults. If session is set, then only updates indices,
     * as they are lost with every script execution, else, sets the default colors by name or value and
     * then updates indices too.
     *
     * FIXME Isn't this too slow?
     *
     */
    function SetDefaultStyles()
    {
        /* Some of the Set*() functions use default values when they get no parameters. */

        if (! isset($this->session_set)) {
            // If sessions are enabled, this variable will be preserved, so upon future executions, we
            // will have it set, as well as color names (though not color indices, that's why we
            // need to rebuild them)
            $this->session_set = TRUE;

            // These only need to be set once
            $this->SetLineWidths();
            $this->SetLineStyles();
            $this->SetDefaultDashedStyle($this->dashed_style);
            $this->SetPointSizes($this->point_sizes);
        }

        $this->SetImageBorderColor($this->i_border);
        $this->SetPlotBgColor($this->plot_bg_color);
        $this->SetBackgroundColor($this->bg_color);
        $this->SetLabelColor($this->label_color);
        $this->SetTextColor($this->text_color);
        $this->SetGridColor($this->grid_color);
        $this->SetLightGridColor($this->light_grid_color);
        $this->SetTickColor($this->tick_color);
        $this->SetTitleColor($this->title_color);
        $this->SetDataColors();
        $this->SetErrorBarColors();
        $this->SetDataBorderColors();
    }


    /*
     *
     */
    function SetBackgroundColor($which_color)
    {
        $this->bg_color= $which_color;
        $this->ndx_bg_color= $this->SetIndexColor($this->bg_color);
        return TRUE;
    }

    /*
     *
     */
    function SetPlotBgColor($which_color)
    {
        $this->plot_bg_color= $which_color;
        $this->ndx_plot_bg_color= $this->SetIndexColor($this->plot_bg_color);
        return TRUE;
    }

   /*
    *
    */
    function SetTitleColor($which_color) 
    {
        $this->title_color= $which_color;
        $this->ndx_title_color= $this->SetIndexColor($this->title_color);
        return TRUE;
    }

    /*
     *
     */
    function SetTickColor ($which_color) 
    {
        $this->tick_color= $which_color;
        $this->ndx_tick_color= $this->SetIndexColor($this->tick_color);
        return TRUE;
    }

    
    /*
     *
     */
    function SetLabelColor ($which_color) 
    {
        $this->label_color = $which_color;
        $this->ndx_title_color= $this->SetIndexColor($this->label_color);
        return TRUE;
    }


    /*
     *
     */
    function SetTextColor ($which_color) 
    {
        $this->text_color= $which_color;
        $this->ndx_text_color= $this->SetIndexColor($this->text_color);
        return TRUE;
    }


    /*
     *
     */
    function SetLightGridColor ($which_color) 
    {
        $this->light_grid_color= $which_color;
        $this->ndx_light_grid_color= $this->SetIndexColor($this->light_grid_color);
        return TRUE;
    }

    
    /*
     *
     */
    function SetGridColor ($which_color) 
    {
        $this->grid_color = $which_color;
        $this->ndx_grid_color= $this->SetIndexColor($this->grid_color);
        return TRUE;
    }


    /*
     *
     */
    function SetImageBorderColor($which_color)
    {
        $this->i_border = $which_color;
        $this->ndx_i_border = $this->SetIndexColor($this->i_border);
        $this->ndx_i_border_dark = $this->SetIndexDarkColor($this->i_border);
        return TRUE;
    }


    /*
     *
     */   
    function SetTransparentColor($which_color)
    { 
        ImageColorTransparent($this->img, $this->SetIndexColor($which_color));
        return TRUE;
    }
    

    /*!
     * Sets the array of colors to be used. It can be user defined, a small predefined one 
     * or a large one included from 'rgb.inc.php'.
     *
     * \param which_color_array If an array, the used as color array. If a string can 
     *        be one of 'small' or 'large'.
     */
    function SetRGBArray ($which_color_array) 
    { 
        if ( is_array($which_color_array) ) {           // User defined array
            $this->rgb_array = $which_color_array;
            return TRUE;
        } elseif ($which_color_array == 'small') {      // Small predefined color array
            $this->rgb_array = array(
                'white'          => array(255, 255, 255),
                'snow'           => array(255, 250, 250),
                'PeachPuff'      => array(255, 218, 185),
                'ivory'          => array(255, 255, 240),
                'lavender'       => array(230, 230, 250),
                'black'          => array(  0,   0,   0),
                'DimGrey'        => array(105, 105, 105),
                'gray'           => array(190, 190, 190),
                'grey'           => array(190, 190, 190),
                'navy'           => array(  0,   0, 128),
                'SlateBlue'      => array(106,  90, 205),
                'blue'           => array(  0,   0, 255),
                'SkyBlue'        => array(135, 206, 235),
                'cyan'           => array(  0, 255, 255),
                'DarkGreen'      => array(  0, 100,   0),
                'green'          => array(  0, 255,   0),
                'YellowGreen'    => array(154, 205,  50),
                'yellow'         => array(255, 255,   0),
                'orange'         => array(255, 165,   0),
                'gold'           => array(255, 215,   0),
                'peru'           => array(205, 133,  63),
                'beige'          => array(245, 245, 220),
                'wheat'          => array(245, 222, 179),
                'tan'            => array(210, 180, 140),
                'brown'          => array(165,  42,  42),
                'salmon'         => array(250, 128, 114),
                'red'            => array(255,   0,   0),
                'pink'           => array(255, 192, 203),
                'maroon'         => array(176,  48,  96),
                'magenta'        => array(255,   0, 255),
                'violet'         => array(238, 130, 238),
                'plum'           => array(221, 160, 221),
                'orchid'         => array(218, 112, 214),
                'purple'         => array(160,  32, 240),
                'azure1'         => array(240, 255, 255),
                'aquamarine1'    => array(127, 255, 212)
                );
            return TRUE;
        } elseif ($which_color_array === 'large')  {    // Large color array
            include("./rgb.inc.php");
            $this->rgb_array = $RGBArray;
        } else {                                        // Default to black and white only.
            $this->rgb_array = array('white' => array(255, 255, 255), 'black' => array(0, 0, 0));
        }

        return TRUE;
    }

    /*!
     * Returns an array in R, G, B format 0-255
     *
     *  \param color_asked array(R,G,B) or string (named color or '#AABBCC')
     */
    function SetRGBColor($color_asked) 
    {
        if ($color_asked == '') { $color_asked = array(0, 0, 0); };

        if ( count($color_asked) == 3 ) {    // already array of 3 rgb
               $ret_val =  $color_asked;
        } else {                             // asking for a color by string
            if(substr($color_asked, 0, 1) == '#') {         // asking in #FFFFFF format. 
                $ret_val = array(hexdec(substr($color_asked, 1, 2)), hexdec(substr($color_asked, 3, 2)), 
                                  hexdec(substr($color_asked, 5, 2)));
            } else {                                        // asking by color name
                $ret_val = $this->rgb_array[$color_asked];
            }
        }
        return $ret_val;
    }


    /*!
     * Sets the colors for the data.
     */
    function SetDataColors($which_data = NULL, $which_border = NULL) 
    {
        if (is_null($which_data) && is_array($this->data_colors)) {
            // use already set data_colors
        } else if (! is_array($which_data)) {
            $this->data_colors = ($which_data) ? array($which_data) : array('blue', 'red', 'green', 'orange');
        } else {
            $this->data_colors = $which_data;
        }

        $i = 0;
        foreach ($this->data_colors as $col) {
            $this->ndx_data_colors[$i] = $this->SetIndexColor($col);
            $this->ndx_data_dark_colors[$i] = $this->SetIndexDarkColor($col);
            $i++;
        }

        // For past compatibility:
        $this->SetDataBorderColors($which_border);
    } // function SetDataColors()


    /*!
     *
     */
    function SetDataBorderColors($which_br = NULL)
    {
        if (is_null($which_br) && is_array($this->data_border_colors)) {
            // use already set data_border_colors
        } else if (! is_array($which_br)) {
            // Create new array with specified color
            $this->data_border_colors = ($which_br) ? array($which_br) : array('black');
        } else {
            $this->data_border_colors = $which_br;
        }

        $i = 0;
        foreach($this->data_border_colors as $col) {
            $this->ndx_data_border_colors[$i] = $this->SetIndexColor($col);
            $i++;
        }
    } // function SetDataBorderColors()


    /*!
     * Sets the colors for the data error bars.
     */
    function SetErrorBarColors($which_err = NULL)
    {
        if (is_null($which_err) && is_array($this->error_bar_colors)) {
            // use already set error_bar_colors
        } else if (! is_array($which_err)) {
            $this->error_bar_colors = ($which_err) ? array($which_err) : array('black');
        } else {
            $this->error_bar_colors = $which_err;
        }

        $i = 0;
        foreach($this->error_bar_colors as $col) {
            $this->ndx_error_bar_colors[$i] = $this->SetIndexColor($col);
            $i++;
        }       
        return TRUE;

    } // function SetErrorBarColors()


    /*!
     * Sets the default dashed style.
     *  \param which_style A string specifying order of colored and transparent dots, 
     *         i.e: '4-3' means 4 colored, 3 transparent; 
     *              '2-3-1-2' means 2 colored, 3 transparent, 1 colored, 2 transparent.
     */
    function SetDefaultDashedStyle($which_style) 
    {
        // String: "numcol-numtrans-numcol-numtrans..."
        $asked = explode('-', $which_style);

        if (count($asked) < 2) {
            $this->DrawError("SetDefaultDashedStyle(): Wrong parameter '$which_style'.");
            return FALSE;
        }

        // Build the string to be eval()uated later by SetDashedStyle()
        $this->default_dashed_style = 'array( ';

        $t = 0;
        foreach($asked as $s) {
            if ($t % 2 == 0) {
                $this->default_dashed_style .= str_repeat('$which_ndxcol,', $s);
            } else {
                $this->default_dashed_style .= str_repeat('IMG_COLOR_TRANSPARENT,', $s);
            }
            $t++;
        }
        // Remove trailing comma and add closing parenthesis
        $this->default_dashed_style = substr($this->default_dashed_style, 0, -1);
        $this->default_dashed_style .= ')';

        return TRUE;
    }


    /*!
     * Sets the style before drawing a dashed line. Defaults to $this->default_dashed_style
     *   \param which_ndxcol Color index to be used.
     */
    function SetDashedStyle($which_ndxcol)
    {
        // See SetDefaultDashedStyle() to understand this.
        eval ("\$style = $this->default_dashed_style;");
        return imagesetstyle($this->img, $style);
    }


    /*!
     * Sets line widths on a per-line basis.
     */
    function SetLineWidths($which_lw=NULL)
    {
        if (is_null($which_lw)) {
            // Do nothing, use default value.
        } else if (is_array($which_lw)) {
            // Did we get an array with line widths?
            $this->line_widths = $which_lw;
        } else {
            $this->line_widths = array($which_lw);
        }
        return TRUE;
    }

    /*!
     *
     */
    function SetLineStyles($which_ls=NULL)
    {
        if (is_null($which_ls)) {
            // Do nothing, use default value.
        } else if (! is_array($which_ls)) {
            // Did we get an array with line styles?
            $this->line_styles = $which_ls;
        } else {
            $this->line_styles = ($which_ls) ? array($which_ls) : array('solid');
        }
        return TRUE;
    }


/////////////////////////////////////////////
//////////////                          FONTS
/////////////////////////////////////////////


    /*!
     * Sets number of pixels between lines of the same text.
     */
    function SetLineSpacing($which_spc)
    {
        $this->line_spacing = $which_spc;
    }


    /*!
     * Enables use of TrueType fonts in the graph. Font initialisation methods
     * depend on this setting, so when called, SetUseTTF() resets the font
     * settings
     */
    function SetUseTTF($which_ttf) 
    {
        $this->use_ttf = $which_ttf;
        if ($which_ttf)
            $this->SetDefaultFonts();
        return TRUE;
    }

    /*!
     * Sets the directory name to look into for TrueType fonts.
     */
    function SetTTFPath($which_path)
    {
        // Maybe someone needs really dynamic config. He'll need this:
        // clearstatcache();

        if (is_dir($which_path) && is_readable($which_path)) {
            $this->ttf_path = $which_path;
            return TRUE;
        } else {
            $this->PrintError("SetTTFPath(): $which_path is not a valid path.");
            return FALSE;
        }
    }

    /*!
     * Sets the default TrueType font and updates all fonts to that.
     */
    function SetDefaultTTFont($which_font)
    {
        if (is_file($which_font) && is_readable($which_font)) {
            $this->default_ttfont = $which_font;
            return $this->SetDefaultFonts();
        } else {
            $this->PrintError("SetDefaultTTFont(): $which_font is not a valid font file.");
            return FALSE;
        }
    }

    /*!
     * Sets fonts to their defaults
     */
    function SetDefaultFonts()
    {
        // TTF:
        if ($this->use_ttf) {
            //$this->SetTTFPath(dirname($_SERVER['PHP_SELF']));
            $this->SetTTFPath(getcwd());
            $this->SetFont('generic', $this->default_ttfont, 8);
            $this->SetFont('title', $this->default_ttfont, 14);
            $this->SetFont('legend', $this->default_ttfont, 8);
            $this->SetFont('x_label', $this->default_ttfont, 6);
            $this->SetFont('y_label', $this->default_ttfont, 6);
            $this->SetFont('x_title', $this->default_ttfont, 10);
            $this->SetFont('y_title', $this->default_ttfont, 10);
        }
        // Fixed:
        else {
            $this->SetFont('generic', 2);
            $this->SetFont('title', 5);
            $this->SetFont('legend', 2);
            $this->SetFont('x_label', 1);
            $this->SetFont('y_label', 1);           
            $this->SetFont('x_title', 3);
            $this->SetFont('y_title', 3);
        }

        return TRUE;
    }

    /*!
     * Sets Fixed/Truetype font parameters.
     *  \param $which_elem Is the element whose font is to be changed.
     *         It can be one of 'title', 'legend', 'generic',
     *         'x_label', 'y_label', x_title' or 'y_title'
     *  \param $which_font Can be a number (for fixed font sizes) or
     *         a string with the filename when using TTFonts.
     *  \param $which_size Point size (TTF only)
     * Calculates and updates internal height and width variables.
     */
    function SetFont($which_elem, $which_font, $which_size = 12) 
    {
        // TTF:
        if ($this->use_ttf) {
            $path = $this->ttf_path.'/'.$which_font;

            if (! is_file($path) || ! is_readable($path) ) {
                $this->DrawError("SetFont(): True Type font $path doesn't exist");
                return FALSE;
            }

            switch ($which_elem) {
            case 'generic':
                $this->generic_font['font'] = $path;
                $this->generic_font['size'] = $which_size;
                break;
            case 'title':
                $this->title_font['font'] = $path;
                $this->title_font['size'] = $which_size;
                break;
            case 'legend':
                $this->legend_font['font'] = $path;
                $this->legend_font['size'] = $which_size;
                break;
            case 'x_label':
                $this->x_label_font['font'] = $path;
                $this->x_label_font['size'] = $which_size;
                break;
            case 'y_label':
                $this->y_label_font['font'] = $path;
                $this->y_label_font['size'] = $which_size;
                break;                   
            case 'x_title':
                $this->x_title_font['font'] = $path;
                $this->x_title_font['size'] = $which_size;
                break;
            case 'y_title':
                $this->y_title_font['font'] = $path;
                $this->y_title_font['size'] = $which_size;
                break;
            default:
                $this->DrawError("SetFont(): Unknown element '$which_elem' specified.");
                return FALSE;
            }
            return TRUE;

        } 

        // Fixed fonts:
        if ($which_font > 5 || $which_font < 0) {
            $this->DrawError('SetFont(): Non-TTF font size must be 1, 2, 3, 4 or 5');
            return FALSE;
        }

        switch ($which_elem) {
        case 'generic':
            $this->generic_font['font'] = $which_font;
            $this->generic_font['height'] = ImageFontHeight($which_font);
            $this->generic_font['width'] = ImageFontWidth($which_font);
            break;
        case 'title':
           $this->title_font['font'] = $which_font;
           $this->title_font['height'] = ImageFontHeight($which_font);
           $this->title_font['width'] = ImageFontWidth($which_font);
           break;
        case 'legend':
            $this->legend_font['font'] = $which_font;
            $this->legend_font['height'] = ImageFontHeight($which_font);
            $this->legend_font['width'] = ImageFontWidth($which_font);
            break;
        case 'x_label':
            $this->x_label_font['font'] = $which_font;
            $this->x_label_font['height'] = ImageFontHeight($which_font);
            $this->x_label_font['width'] = ImageFontWidth($which_font);
            break;
        case 'y_label':
            $this->y_label_font['font'] = $which_font;
            $this->y_label_font['height'] = ImageFontHeight($which_font);
            $this->y_label_font['width'] = ImageFontWidth($which_font);
            break;               
        case 'x_title':
            $this->x_title_font['font'] = $which_font;
            $this->x_title_font['height'] = ImageFontHeight($which_font);
            $this->x_title_font['width'] = ImageFontWidth($which_font);
            break;
        case 'y_title':
            $this->y_title_font['font'] = $which_font;
            $this->y_title_font['height'] = ImageFontHeight($which_font);
            $this->y_title_font['width'] = ImageFontWidth($which_font);
            break;
        default:
            $this->DrawError("SetFont(): Unknown element '$which_elem' specified.");
            return FALSE;
        }
        return TRUE;
    }


    /*!
     * Returns an array with the size of the bounding box of an
     * arbitrarily placed (rotated) TrueType text string.
     */
    function TTFBBoxSize($size, $angle, $font, $string) 
    {
        // First, assume angle < 90
        $arr = ImageTTFBBox($size, 0, $font, $string);
        $flat_width  = $arr[2] - $arr[0];
        $flat_height = abs($arr[3] - $arr[5]);

        // Now the bounding box
        $angle = deg2rad($angle);
        $width  = ceil(abs($flat_width*cos($angle) + $flat_height*sin($angle))); //Must be integer
        $height = ceil(abs($flat_width*sin($angle) + $flat_height*cos($angle))); //Must be integer

        return array($width, $height);
    }


    /*!
     * Draws a string of text. Horizontal and vertical alignment are relative to
     * to the drawing. That is: vertical text (90 deg) gets centered along y-axis 
     * with v_align = 'center', and adjusted to the left of x-axis with h_align = 'right',
     *
     * \note Original multiple lines code submitted by Remi Ricard.
     * \note Original vertical code submitted by Marlin Viss.
     */
    function DrawText($which_font, $which_angle, $which_xpos, $which_ypos, $which_color, $which_text,
                      $which_halign = 'left', $which_valign = 'bottom') 
    {
        // TTF:
        if ($this->use_ttf) {
            $size = $this->TTFBBoxSize($which_font['size'], $which_angle, $which_font['font'], $which_text);
            $rads = deg2rad($which_angle);

            if ($which_valign == 'center')
                $which_ypos += $size[1]/2;

            if ($which_valign == 'bottom')
                $which_ypos += $size[1];

            if ($which_halign == 'center')
                $which_xpos -= ($size[0]/2) * cos($rads);

            if ($which_halign == 'left')
                $which_xpos += $size[0] * sin($rads);

            if ($which_halign == 'right')
                $which_xpos -= $size[0] * cos($rads);

            ImageTTFText($this->img, $which_font['size'], $which_angle, 
                         $which_xpos, $which_ypos, $which_color, $which_font['font'], $which_text);
        }
        // Fixed fonts:
        else {
            // Split the text by its lines, and count them
            $which_text = ereg_replace("\r", "", $which_text);
            $str = split("\n", $which_text);
            $nlines = count($str);
            $spacing = $this->line_spacing * ($nlines - 1);

            // Vertical text:
            // (Remember the alignment convention with vertical text)
            if ($which_angle == 90) {
                // The text goes around $which_xpos.
                if ($which_halign == 'center')
                    $which_xpos -= ($nlines * ($which_font['height'] + $spacing))/2;

                // Left alignment requires no modification to $xpos...
                // Right-align it. $which_xpos designated the rightmost x coordinate.
                else if ($which_halign == 'right')
                    $which_xpos += ($nlines * ($which_font['height'] + $spacing));

                $ypos = $which_ypos;
                for($i = 0; $i < $nlines; $i++) { 
                    // Center the text vertically around $which_ypos (each line)
                    if ($which_valign == 'center')
                        $ypos = $which_ypos + (strlen($str[$i]) * $which_font['width']) / 2;
                    // Make the text finish (vertically) at $which_ypos
                    if ($which_valign == 'bottom')
                        $ypos = $which_ypos + strlen($str[$i]) * $which_font['width'];

                    ImageStringUp($this->img, $which_font['font'],
                                  $i * ($which_font['height'] + $spacing) + $which_xpos,
                                  $ypos, $str[$i], $which_color);
                } 
            }
            // Horizontal text:
            else {
                // The text goes above $which_ypos
                if ($which_valign == 'top')
                    $which_ypos -= $nlines * ($which_font['height'] + $spacing);
                // The text is centered around $which_ypos
                if ($which_valign == 'center')
                    $which_ypos -= ($nlines * ($which_font['height'] + $spacing))/2;
                // valign = 'bottom' requires no modification

                $xpos = $which_xpos;
                for($i = 0; $i < $nlines; $i++) {
                    // center the text around $which_xpos
                    if ($which_halign == 'center')
                        $xpos = $which_xpos - (strlen($str[$i]) * $which_font['width'])/2;
                    // make the text finish at $which_xpos
                    if ($which_halign == 'right')
                        $xpos = $which_xpos - strlen($str[$i]) * $which_font['width'];

                    ImageString($this->img, $which_font['font'], $xpos, 
                                $i * ($which_font['height'] + $spacing) + $which_ypos,
                                $str[$i], $which_color);
                }                 
            }
        } 
        return TRUE;
    } // function DrawText()


/////////////////////////////////////////////
///////////            INPUT / OUTPUT CONTROL
/////////////////////////////////////////////

    /*!
     * Sets output file format.
     */
    function SetFileFormat($format)
    {
        $asked = $this->CheckOption($format, 'jpg, png, gif, wbmp', __FUNCTION__);

        switch ($asked) {
        case 'jpg':
            if (imagetypes() & IMG_JPG)
                $this->file_format = 'jpg';
                return TRUE;
            break;
        case 'png':
            if (imagetypes() & IMG_PNG)
                $this->file_format = 'png';
                return TRUE;
            break;
        case 'gif':
            if (imagetypes() & IMG_GIF)
                $this->file_format = 'gif';
                return TRUE;
            break;
        case 'wbmp':
            if (imagetypes() & IMG_WBMP)
                $this->file_format = 'wbmp';
                return TRUE;
            break;
        default:
            $this->PrintError("SetFileFormat():File format '$format' not supported");
            return FALSE;
        }
    }


    /*!
     * Selects an input file to be used as graph background and scales or tiles this image
     * to fit the sizes.
     *  \param input_file string Path to the file to be used (jpeg, png and gif accepted)
     *  \param mode       string 'centeredtile', 'tile', 'scale' (the image to the graph's size)
     */
    function SetBgImage($input_file, $mode='centeredtile')
    {
        $this->bgmode = $this->CheckOption($mode, 'tile, centeredtile, scale', __FUNCTION__);
        $this->bgimg  = $input_file;
    }

    /*!
     * Selects an input file to be used as plot area background and scales or tiles this image
     * to fit the sizes.
     *  \param input_file string Path to the file to be used (jpeg, png and gif accepted)
     *  \param mode       string 'centeredtile', 'tile', 'scale' (the image to the graph's size)
     */
    function SetPlotAreaBgImage($input_file, $mode='tile')
    {
        $this->plotbgmode = $this->CheckOption($mode, 'tile, centeredtile, scale', __FUNCTION__);
        $this->plotbgimg  = $input_file;
    }


    /*!
     * Sets the name of the file to be used as output file.
     */
    function SetOutputFile($which_output_file)
    {
        $this->output_file = $which_output_file;
        return TRUE;
    }

    /*!
     * Sets the output image as 'inline', that is: no Content-Type headers are sent
     * to the browser. Needed if you want to embed the images.
     */
    function SetIsInline($which_ii)
    {
        $this->is_inline = (bool)$which_ii;
        return TRUE;
    }


    /*!
     * Performs the actual outputting of the generated graph, and
     * destroys the image resource.
     */
    function PrintImage()
    {
        // Browser cache stuff submitted by Thiemo Nagel
        if ( (! $this->browser_cache) && (! $this->is_inline)) {
            header('Expires: Mon, 26 Jul 1997 05:00:00 GMT');
            header('Last-Modified: ' . gmdate('D, d M Y H:i:s') . 'GMT');
            header('Cache-Control: no-cache, must-revalidate');
            header('Pragma: no-cache');
        }

        switch($this->file_format) {
        case 'png':
            if (! $this->is_inline) {
                Header('Content-type: image/png');
            }
            if ($this->is_inline && $this->output_file != '') {
                ImagePng($this->img, $this->output_file);
            } else {
                ImagePng($this->img);
            }
            break;
        case 'jpg':
            if (! $this->is_inline) {
                Header('Content-type: image/jpeg');
            }
            if ($this->is_inline && $this->output_file != '') {
                ImageJPEG($this->img, $this->output_file);
            } else {
                ImageJPEG($this->img);
            }
            break;
        case 'gif':
            if (! $this->is_inline) {
                Header('Content-type: image/gif');
            }
            if ($this->is_inline && $this->output_file != '') {
                ImageGIF($this->img, $this->output_file);
            } else {
                ImageGIF($this->img);
            }

            break;
        case 'wbmp':        // wireless bitmap, 2 bit.
            if (! $this->is_inline) {
                Header('Content-type: image/wbmp');
            }
            if ($this->is_inline && $this->output_file != '') {
                ImageWBMP($this->img, $this->output_file);
            } else {
                ImageWBMP($this->img);
            }

            break;
        default:
            $this->PrintError('PrintImage(): Please select an image type!');
            break;
        }
        return TRUE;
    }

    /*! 
     * Prints an error message to stdout and dies 
     */
    function PrintError($error_message) 
    {
        echo "<p><b>Fatal error</b>: $error_message<p>";
        die;
    }

    /*!
     * Prints an error message inline into the generated image and draws it centered
     * around the given coordinates (defaults to center of the image)
     *   \param error_message Message to be drawn
     *   \param where_x       X coordinate
     *   \param where_y       Y coordinate
     */
    function DrawError($error_message, $where_x = NULL, $where_y = NULL) 
    {
        if (! $this->img)
            $this->PrintError('_DrawError(): Warning, no image resource allocated. '.
                              'The message to be written was: '.$error_message);

        $ypos = (! $where_y) ? $this->image_height/2 : $where_y;
        $xpos = (! $where_x) ? $this->image_width/2 : $where_x;
        ImageRectangle($this->img, 0, 0, $this->image_width, $this->image_height,
                       ImageColorAllocate($this->img, 255, 255, 255));

        $this->DrawText($this->generic_font, 0, $xpos, $ypos, ImageColorAllocate($this->img, 0, 0, 0),
                        $error_message, 'center', 'center');

        $this->PrintImage();
        exit;
//        return TRUE;
    }

/////////////////////////////////////////////
///////////                            LABELS
/////////////////////////////////////////////


    /*!
     * Sets position for X labels following data points.
     */
    function SetXDataLabelPos($which_xdlp)
    {
        $this->x_data_label_pos = $this->CheckOption($which_xdlp, 'plotdown, plotup, both, xaxis, all, none',
                                                      __FUNCTION__);
        if ($which_xdlp != 'none')
            $this->x_tick_label_pos = 'none';

        return TRUE;
    }

    /*!
     * Sets position for Y labels following data points.
     */
    function SetYDataLabelPos($which_ydlp) 
    {
        $this->y_data_label_pos = $this->CheckOption($which_ydlp, 'plotleft, plotright, both, yaxis, all, none',
                                                      __FUNCTION__);
        if ($which_ydlp != 'none')
            $this->y_tick_label_pos = 'none';

        return TRUE;
    }


    /*!
     * Sets position for X labels following ticks (hence grid lines)
     */
    function SetXTickLabelPos($which_xtlp) 
    {
        $this->x_tick_label_pos = $this->CheckOption($which_xtlp, 'plotdown, plotup, both, xaxis, all, none',
                                                      __FUNCTION__);
        if ($which_xtlp != 'none')
            $this->x_data_label_pos = 'none';

        return TRUE;
    }

    /*!
     * Sets position for Y labels following ticks (hence grid lines)
     */
    function SetYTickLabelPos($which_ytlp) 
    {
        $this->y_tick_label_pos = $this->CheckOption($which_ytlp, 'plotleft, plotright, both, yaxis, all, none',
                                                      __FUNCTION__);
        if ($which_ytlp != 'none')
            $this->y_data_label_pos = 'none';

        return TRUE;
    }

    /*!
     * Sets type for tick and data labels on X axis.
     * \note 'title' type left for backwards compatibility.
     */
    function SetXLabelType($which_xlt) 
    {
        $this->x_label_type = $this->CheckOption($which_xlt, 'data, time, title', __FUNCTION__);
        return TRUE;
    }

    /*!
     * Sets type for tick and data labels on Y axis.
     */
    function SetYLabelType($which_ylt) 
    {
        $this->y_label_type = $this->CheckOption($which_ylt, 'data, time', __FUNCTION__);
        return TRUE;
    }

    function SetXTimeFormat($which_xtf) 
    {
        $this->x_time_format = $which_xtf;
        return TRUE;
    }
    function SetYTimeFormat($which_ytf) 
    {
        $this->y_time_format = $which_ytf;
        return TRUE;
    }

    function SetXLabelAngle($which_xla) 
    {
        $this->x_label_angle = $which_xla;
        return TRUE;
    }

    function SetYLabelAngle($which_yla)
    {
        $this->y_label_angle = $which_yla;
        return TRUE;
    }

/////////////////////////////////////////////
///////////                              MISC
/////////////////////////////////////////////

    /*!
     * Checks the valididy of an option.
     *  \param which_opt  String to check.
     *  \param which_acc  String of accepted choices.
     *  \param which_func Name of the calling function, for error messages.
     *  \note If checking everywhere for correctness slows things down, we could provide a
     *        child class overriding every Set...() method which uses CheckOption(). Those new
     *        methods could proceed in the unsafe but faster way.
     */
    function CheckOption($which_opt, $which_acc, $which_func)
    {
        $asked = trim($which_opt);

        // FIXME: this for backward compatibility, as eregi() fails with empty strings.
        if ($asked == '')
            return '';

        $asked = strtolower($asked);
        if (@ eregi($asked, $which_acc)) {
            return $asked;
        } else {
            $this->DrawError("$which_func(): '$which_opt' not in available choices: '$which_acc'.");
            return NULL;
        }
    }


    /*!
     *  \note Submitted by Thiemo Nagel
     */
    function SetBrowserCache($which_browser_cache)
    {
        $this->browser_cache = $which_browser_cache;
        return TRUE;
    }

    /*!
     * Whether to show the final image or not
     */
    function SetPrintImage($which_pi)
    {
        $this->print_image = $which_pi;
        return TRUE;
    }

    /*!
     * Sets the graph's legend. If argument is not an array, appends it to the legend.
     */
    function SetLegend($which_leg)
    {
        if (is_array($which_leg)) {             // use array
            $this->legend = $which_leg;
            return TRUE;
        } else if (! is_null($which_leg)) {     // append string
            $this->legend[] = $which_leg;
            return TRUE;
        } else {
            $this->DrawError("SetLegend(): argument must not be null.");
            return FALSE;
        }
    }

    /*!
     * Specifies the absolute (relative to image's up/left corner) position
     * of the legend's upper/leftmost corner.
     *  $which_type not yet used (TODO)
     */
    function SetLegendPixels($which_x, $which_y, $which_type=NULL) 
    { 
        $this->legend_x_pos = $which_x;
        $this->legend_y_pos = $which_y;

        return TRUE;
    }

    /*!
     * Specifies the relative (to graph's origin) position of the legend's
     * upper/leftmost corner. MUST be called after scales are set up.
     *   $which_type not yet used (TODO)
     */
    function SetLegendWorld($which_x, $which_y, $which_type=NULL) 
    { 
        if (! isset($this->scale_is_set))
            $this->CalcTranslation();

        $this->legend_x_pos = $this->xtr($which_x);
        $this->legend_y_pos = $this->ytr($which_y);

        return TRUE;
    }

    /*!
     * Accepted values are: left, sides, none, full
     */
    function SetPlotBorderType($pbt)
    {
        $this->plot_border_type = $this->CheckOption($pbt, 'left, sides, none, full', __FUNCTION__);
    }

    /*!
     * Accepted values are: raised, plain
     */
    function SetImageBorderType($sibt) 
    {
        $this->image_border_type = $this->CheckOption($sibt, 'raised, plain', __FUNCTION__);
    }


    /*!
     * \param dpab bool
     */
    function SetDrawPlotAreaBackground($dpab)
    {
        $this->draw_plot_area_background = (bool)$dpab;
    }


    /*!
     * \param dyg bool 
     */
    function SetDrawYGrid($dyg) 
    {
        $this->draw_y_grid = (bool)$dyg;
        return TRUE;
    }


    /*!
     * \param dxg bool
     */
    function SetDrawXGrid($dxg) 
    {
        $this->draw_x_grid = (bool)$dxg;
        return TRUE;
    }


    /*!
     * \param ddg bool 
     */
    function SetDrawDashedGrid($ddg) 
    {
        $this->dashed_grid = (bool)$ddg;
        return TRUE;
    }


    /*!
     * \param dxdl bool
     */
    function SetDrawXDataLabelLines($dxdl)
    {
        $this->draw_x_data_label_lines = (bool)$dxdl;
        return TRUE;
    }

    
    /*!
     * TODO: draw_y_data_label_lines not implemented.
     * \param dydl bool
     */
    function SetDrawYDataLabelLines($dydl)
    {
        $this->draw_y_data_label_lines = $dydl;
        return TRUE;
    }
    
    /*!
     * Sets the graph's title.
     * TODO: add parameter to choose title placement: left, right, centered=
     */
    function SetTitle($which_title) 
    {
        $this->title_txt = $which_title;

        if ($which_title == '') {
            $this->title_height = 0;
            return TRUE;
        }            

        $str = split("\n", $which_title);
        $lines = count($str);
        $spacing = $this->line_spacing * ($lines - 1);

        if ($this->use_ttf) {
            $size = $this->TTFBBoxSize($this->title_font['size'], 0, $this->title_font['font'], $which_title);
            $this->title_height = $size[1] * $lines;
        } else {
            $this->title_height = ($this->title_font['height'] + $spacing) * $lines;
        }   
        return TRUE;
    }

    /*!
     * Sets the X axis title and position.
     */
    function SetXTitle($which_xtitle, $which_xpos = 'plotdown') 
    {
        if ($which_xtitle == '')
            $which_xpos = 'none';

        $this->x_title_pos = $this->CheckOption($which_xpos, 'plotdown, plotup, both, none', __FUNCTION__);

        $this->x_title_txt = $which_xtitle;

        $str = split("\n", $which_xtitle);
        $lines = count($str);
        $spacing = $this->line_spacing * ($lines - 1);

        if ($this->use_ttf) {
            $size = $this->TTFBBoxSize($this->x_title_font['size'], 0, $this->x_title_font['font'], $which_xtitle);
            $this->x_title_height = $size[1] * $lines;
        } else {
            $this->x_title_height = ($this->y_title_font['height'] + $spacing) * $lines;
        }

        return TRUE;
    }


    /*!
     * Sets the Y axis title and position.
     */
    function SetYTitle($which_ytitle, $which_ypos = 'plotleft') 
    {
        if ($which_ytitle == '')
            $which_ypos = 'none';

        $this->y_title_pos = $this->CheckOption($which_ypos, 'plotleft, plotright, both, none', __FUNCTION__);

        $this->y_title_txt = $which_ytitle;

        $str = split("\n", $which_ytitle);
        $lines = count($str);
        $spacing = $this->line_spacing * ($lines - 1);

        if ($this->use_ttf) {
            $size = $this->TTFBBoxSize($this->y_title_font['size'], 90, $this->y_title_font['font'], 
                                       $which_ytitle);
            $this->y_title_width = $size[0] * $lines;
        } else {
            $this->y_title_width = ($this->y_title_font['height'] + $spacing) * $lines;
        }

        return TRUE;
    }

    /*!
     * Sets the size of the drop shadow for bar and pie charts.
     * \param which_s int Size in pixels.
     */
    function SetShading($which_s) 
    { 
        $this->shading = (int)$which_s;
        return TRUE;
    }

    function SetPlotType($which_pt) 
    {
        $this->plot_type = $this->CheckOption($which_pt, 
                           'bars, stackedbars, lines, linepoints, area, points, pie, thinbarline, squared', 
                            __FUNCTION__);
    }

    /*!
     * Sets the position of Y axis.
     * \param pos int Position in world coordinates.
     */
    function SetYAxisPosition($pos)
    {
        $this->y_axis_position = (int)$pos;
        if (isset($this->scale_is_set)) {
            $this->CalcTranslation();
        }
        return TRUE;
    }
    
    /*!
     * Sets the position of X axis.
     * \param pos int Position in world coordinates. 
     */
    function SetXAxisPosition($pos)
    {
        $this->x_axis_position = (int)$pos;
        if (isset($this->scale_is_set)) {
            $this->CalcTranslation();
        }
        return TRUE;
    }


    function SetXScaleType($which_xst)
    {
        $this->xscale_type = $this->CheckOption($which_xst, 'linear, log', __FUNCTION__);
        return TRUE;
    }

    function SetYScaleType($which_yst)
    {
        $this->yscale_type = $this->CheckOption($which_yst, 'linear, log',  __FUNCTION__);
        return TRUE;
    }

    function SetPrecisionX($which_prec)
    {
        $this->x_precision = $which_prec;
        $this->SetXLabelType('data');
        return TRUE;
    }

    function SetPrecisionY($which_prec)
    {
        $this->y_precision = $which_prec;
        $this->SetYLabelType('data');
        return TRUE;
    }

    function SetErrorBarLineWidth($which_seblw)
    {
        $this->error_bar_line_width = $which_seblw;
        return TRUE;
    }

    function SetLabelScalePosition($which_blp)
    {
        //0 to 1
        $this->label_scale_position = $which_blp;
        return TRUE;
    }

    function SetErrorBarSize($which_ebs)
    {
        //in pixels
        $this->error_bar_size = $which_ebs;
        return TRUE;
    }

    /*!
     * Can be one of: 'tee', 'line'
     */
    function SetErrorBarShape($which_ebs)
    {
        $this->error_bar_shape = $this->CheckOption($which_ebs, 'tee, line', __FUNCTION__);
    }

    /*!
     * Sets point shape for each data set via an array.
     * Shape can be one of: 'halfline', 'line', 'plus', 'cross', 'rect', 'circle', 'dot',
     * 'diamond', 'triangle', 'trianglemid'
     */
    function SetPointShapes($which_pt)
    {
        if (is_null($which_pt)) {
            // Do nothing, use default value.
        } else if (is_array($which_pt)) {
            // Did we get an array with point shapes?
            $this->point_shapes = $which_pt;
        } else {
            // Single value into array
            $this->point_shapes = array($which_pt);
        }

        foreach ($this->point_shapes as $shape)
        {
            // TODO, better check, per element rectification
            $this->CheckOption($shape,
               'halfline, line, plus, cross, rect, circle, dot, diamond, triangle, trianglemid',
                __FUNCTION__);
        }

        // Make both point_shapes and point_sizes same size.
        $ps = count($this->point_sizes);
        $pt = count($this->point_shapes);

        if ($ps < $pt) {
            array_pad_array($this->point_sizes, $pt);
        } else if ($pt > $ps) {
            array_pad_array($this->point_shapes, $ps);
        }
        return TRUE;
    }

    /*!
     * Sets the point size for point plots.
     * \param ps int Size in pixels.
     * \note Test this more extensively
     */
    function SetPointSizes($which_ps)
    {
        if (is_null($which_ps)) {
            // Do nothing, use default value.
        } else if (is_array($which_ps)) {
            // Did we get an array with point sizes?
            $this->point_sizes = $which_ps;
        } else {
            // Single value into array
            $this->point_sizes = array($which_ps);
        }

        // Make both point_shapes and point_sizes same size.
        $ps = count($this->point_sizes);
        $pt = count($this->point_shapes);

        if ($ps < $pt) {
            array_pad_array($this->point_sizes, $pt);
        } else if ($pt > $ps) {
            array_pad_array($this->point_shapes, $ps);
        }

        // Fix odd point sizes for point shapes which need it
        for ($i = 0; $i < $pt; $i++) {
            if ($this->point_shapes[$i] == 'diamond' or $this->point_shapes[$i] == 'triangle') {
                if ($this->point_sizes[$i] % 2 != 0) {
                    $this->point_sizes[$i]++;
                }
            }
        }
        return TRUE;
    }


    /*!
     * Tells not to draw lines for missing Y data. Only works with 'lines' and 'squared' plots.
     * \param bl bool
     */
    function SetDrawBrokenLines($bl)
    {
        $this->draw_broken_lines = (bool)$bl;
    }


    /*!
     *  text-data: ('label', y1, y2, y3, ...)
     *  text-data-single: ('label', data), for some pie charts.
     *  data-data: ('label', x, y1, y2, y3, ...)
     *  data-data-error: ('label', x1, y1, e1+, e2-, y2, e2+, e2-, y3, e3+, e3-, ...)
     */
    function SetDataType($which_dt)
    {
        //The next four lines are for past compatibility.
        if ($which_dt == 'text-linear') { $which_dt = 'text-data'; };
        if ($which_dt == 'linear-linear') { $which_dt = 'data-data'; };
        if ($which_dt == 'linear-linear-error') { $which_dt = 'data-data-error'; };
        if ($which_dt == 'text-data-pie') { $which_dt = 'text-data-single'; }


        $this->data_type = $this->CheckOption($which_dt, 'text-data, text-data-single, '.
                                                         'data-data, data-data-error', __FUNCTION__);
        return TRUE;
    }

    /*!
     * Copy the array passed as data values. We convert to numerical indexes, for its
     * use for (or while) loops, which sometimes are faster. Performance improvements
     * vary from 28% in DrawLines() to 49% in DrawArea() for plot drawing functions.
     */
    function SetDataValues(&$which_dv)
    {
        unset ($this->data_limits_done);        // Reset this for every new data_set
        $this->num_data_rows = count($which_dv);
        $this->total_records = 0;               // Perform some useful calculations.
        $this->records_per_group = 1;           
        for ($i = 0, $recs = 0; $i < $this->num_data_rows; $i++) {
            // Copy
            $this->data[$i] = array_values($which_dv[$i]);   // convert to numerical indices.

            // Compute some values
            $recs = count($this->data[$i]); 
            $this->total_records += $recs;

            if ($recs > $this->records_per_group)
                $this->records_per_group = $recs;

            $this->num_recs[$i] = $recs;
        }
    }

    /*!
     * Pad styles arrays for later use by plot drawing functions:
     * This removes the need for $max_data_colors, etc. and $color_index = $color_index % $max_data_colors
     * in DrawBars(), DrawLines(), etc.
     */
    function PadArrays()
    {
        array_pad_array($this->line_widths, $this->records_per_group);
        array_pad_array($this->line_styles, $this->records_per_group);

        array_pad_array($this->data_colors, $this->records_per_group);
        array_pad_array($this->data_border_colors, $this->records_per_group);
        array_pad_array($this->error_bar_colors, $this->records_per_group);

        $this->SetDataColors();
        $this->SetDataBorderColors();
        $this->SetErrorBarColors();

        return TRUE;
    }


//////////////////////////////////////////////////////////
///////////         DATA ANALYSIS, SCALING AND TRANSLATION
//////////////////////////////////////////////////////////

    /*!
     * Analizes data and sets up internal maxima and minima
     * Needed by: CalcMargins(), ...
     *   Text-Data is different than data-data graphs. For them what
     *   we have, instead of X values, is # of records equally spaced on data.
     *   text-data is passed in as $data[] = (title, y1, y2, y3, y4, ...)
     *   data-data is passed in as $data[] = (title, x, y1, y2, y3, y4, ...)
     */
    function FindDataLimits()
    {
	if (!isset($this->data)) {
		return FALSE;
	}


        // Set some default min and max values before running through the data
        switch ($this->data_type) {
        case 'text-data':
            $minx = 0;
            $maxx = $this->num_data_rows - 1 ;
            $miny = $this->data[0][1];
            $maxy = $miny;
            break;
        default:  //Everything else: data-data, etc, take first value
            $minx = $this->data[0][1];
            $maxx = $minx;
            $miny = $this->data[0][2];
            $maxy = $miny;
            break;
        }

        $mine = 0;  // Maximum value for the -error bar (assume error bars always > 0)
        $maxe = 0;  // Maximum value for the +error bar (assume error bars always > 0)
        $maxt = 0;  // Maximum number of characters in text labels

        $minminy = $miny;
        $maxmaxy = $maxy;

        if ($this->plot_type == 'stackedbars') { $maxmaxy = $minminy = 0; }

        // Process each row of data
        for ($i=0; $i < $this->num_data_rows; $i++) {
            $j=0;
            // Extract maximum text label length
            $val = @ strlen($this->data[$i][$j++]);
            $maxt = ($val > $maxt) ? $val : $maxt;


            if ($this->plot_type == 'stackedbars') { $maxy = $miny = 0; }

            switch ($this->data_type) {
            case 'text-data':           // Data is passed in as (title, y1, y2, y3, ...)
            case 'text-data-single':    // This one is for some pie charts
                // $numrecs = @ count($this->data[$i]);
                $miny = $maxy = (double)$this->data[$i][$j];
                for (; $j < $this->num_recs[$i]; $j++) {
                    $val = (double)$this->data[$i][$j];
                    if ($this->plot_type == 'stackedbars') {
                        $maxy += abs($val);      // only positive values for the moment
                    } else {
                        $maxy = ($val > $maxy) ? $val : $maxy;
                        $miny = ($val < $miny) ? $val : $miny;
                    }
                }
                break;
            case 'data-data':           // Data is passed in as (title, x, y, y2, y3, ...)
                // X value:
                $val = (double)$this->data[$i][$j++];
                $maxx = ($val > $maxx) ? $val : $maxx;
                $minx = ($val < $minx) ? $val : $minx;

                $miny = $maxy = (double)$this->data[$i][$j];
                // $numrecs = @ count($this->data[$i]);
                for (; $j < $this->num_recs[$i]; $j++) {
                    $val = (double)$this->data[$i][$j];
                    $maxy = ($val > $maxy) ? $val : $maxy;
                    $miny = ($val < $miny) ? $val : $miny;
                }
                break;
            case 'data-data-error':     // Data is passed in as (title, x, y, err+, err-, y2, err2+, err2-,...)
                // X value:
                $val = (double)$this->data[$i][$j++];
                $maxx = ($val > $maxx) ? $val : $maxx;
                $minx = ($val < $minx) ? $val : $minx;

                $miny = $maxy = (double)$this->data[$i][$j];
                // $numrecs = @ count($this->data[$i]);
                for (; $j < $this->num_recs[$i];) {
                    // Y value:
                    $val = (double)$this->data[$i][$j++];
                    $maxy = ($val > $maxy) ? $val : $maxy;
                    $miny = ($val < $miny) ? $val : $miny;
                    // Error +:
                    $val = (double)$this->data[$i][$j++];
                    $maxe = ($val > $maxe) ? $val : $maxe;
                    // Error -:
                    $val = (double)$this->data[$i][$j++];
                    $mine = ($val > $mine) ? $val : $mine;
                }
                $maxy = $maxy + $maxe;
                $miny = $miny - $mine;      // assume error bars are always > 0
                break;
            default:
                $this->PrintError("FindDataLimits(): Unknown data type '$data_type'.");
            break;
            }
            $this->data[$i][MINY] = $miny;      // This row's min Y, for DrawXDataLine()
            $this->data[$i][MAXY] = $maxy;      // This row's max Y, for DrawXDataLine()

            $minminy = ($miny < $minminy) ? $miny : $minminy;   // global min
            $maxmaxy = ($maxy > $maxmaxy) ? $maxy : $maxmaxy;   // global max
        }

        $this->min_x = $minx;
        $this->max_x = $maxx;
        $this->min_y = $minminy;
        $this->max_y = $maxmaxy;
        $this->max_t = $maxt;

        $this->data_limits_done = TRUE;

        return TRUE;
    }


    /*!
     * Calculates image margins on the fly from title positions and sizes,
     * and tick labels positions and sizes.
     *
     * FIXME: fix x_data_label_pos behaviour. Now we are leaving room for it AND x_tick_label_pos
     *        maybe it shouldn't be so...
     *
     * FIXME: y_data_label_pos is not yet used...
     *
     * TODO: add x_tick_label_width and y_tick_label_height and use them to calculate
     *       max_x_labels and max_y_labels, to be used by drawing functions to avoid overlapping.
     */
    function CalcMargins()
    {
        // Temporary variables for label size calculation
        $xlab = $this->FormatLabel('x', $this->max_x);
        $ylab = $this->FormatLabel('y', $this->max_y);

        // dirty fix:
        // max_t is the maximum data label length (from column 0 of each data row).
        if ($this->max_t > strlen ($xlab))
            $xlab = sprintf ("%{$this->max_t}s","_");

        //////// Calculate maximum X/Y axis label height and width:

        // TTFonts:
        if ($this->use_ttf) {
            // Maximum X axis label height
            $size = $this->TTFBBoxSize($this->x_label_font['size'], $this->x_label_angle,
                                       $this->x_label_font['font'], $xlab);
            $this->x_tick_label_height = $size[1];

            // Maximum Y axis label width
            $size = $this->TTFBBoxSize($this->y_label_font['size'], $this->y_label_angle,
                                        $this->y_label_font['font'], $ylab);
            $this->y_tick_label_width = $size[0];
        }
        // Fixed fonts:
        else {
            // Maximum X axis label height
            if ($this->x_label_angle == 90)
                $this->x_tick_label_height = strlen($xlab) * $this->x_label_font['width'];
            else
                $this->x_tick_label_height = $this->x_label_font['height'];

            // Maximum Y axis label width
            $this->y_tick_label_width = strlen($ylab) * $this->y_label_font['width'];
        }


        ///////// Calculate margins:

        // Upper title, ticks and tick labels, and data labels:
        $this->y_top_margin = $this->title_height + $this->safe_margin * 2;

        if ($this->x_title_pos == 'plotup' || $this->x_title_pos == 'both')
            $this->y_top_margin += $this->x_title_height + $this->safe_margin;

        if ($this->x_tick_label_pos == 'plotup' || $this->x_tick_label_pos == 'both')
            $this->y_top_margin += $this->x_tick_label_height;

        if ($this->x_tick_pos == 'plotup' || $this->x_tick_pos == 'both')
            $this->y_top_margin += $this->x_tick_length * 2;

        if ($this->x_data_label_pos == 'plotup' || $this->x_data_label_pos == 'both')
            $this->y_top_margin += $this->x_tick_label_height;

        // Lower title, ticks and tick labels, and data labels:
        $this->y_bot_margin = $this->safe_margin * 2;

        if ($this->x_title_pos == 'plotdown' || $this->x_title_pos == 'both')
            $this->y_bot_margin += $this->x_title_height;

        if ($this->x_tick_pos == 'plotdown' || $this->x_tick_pos == 'both')
            $this->y_bot_margin += $this->x_tick_length * 2;

        if ($this->x_tick_pos == 'xaxis' && ($this->x_axis_position == '' || $this->x_axis_position == 0))
            $this->y_bot_margin += $this->x_tick_length * 2;

        if ($this->x_tick_label_pos == 'plotdown' || $this->x_tick_label_pos == 'both')            
            $this->y_bot_margin += $this->x_tick_label_height;

        if ($this->x_tick_label_pos == 'xaxis' && ($this->x_axis_position == '' || $this->x_axis_position == 0))
            $this->y_bot_margin += $this->x_tick_label_height;

        if ($this->x_data_label_pos == 'plotdown' || $this->x_data_label_pos == 'both')
            $this->y_bot_margin += $this->x_tick_label_height;

        // Left title, ticks and tick labels:
        $this->x_left_margin = $this->safe_margin * 2;

        if ($this->y_title_pos == 'plotleft' || $this->y_title_pos == 'both')
            $this->x_left_margin += $this->y_title_width + $this->safe_margin;

        if ($this->y_tick_label_pos == 'plotleft' || $this->y_tick_label_pos == 'both')
            $this->x_left_margin += $this->y_tick_label_width;

        if ($this->y_tick_pos == 'plotleft' || $this->y_tick_pos == 'both')
            $this->x_left_margin += $this->y_tick_length * 2 ;

        // Right title, ticks and tick labels:
        $this->x_right_margin = $this->safe_margin * 2;

        if ($this->y_title_pos == 'plotright' || $this->y_title_pos == 'both')
            $this->x_right_margin += $this->y_title_width + $this->safe_margin;

        if ($this->y_tick_label_pos == 'plotright' || $this->y_tick_label_pos == 'both')
            $this->x_right_margin += $this->y_tick_label_width;

        if ($this->y_tick_pos == 'plotright' || $this->y_tick_pos == 'both')
            $this->x_right_margin += $this->y_tick_length * 2;


        $this->x_tot_margin = $this->x_left_margin + $this->x_right_margin;
        $this->y_tot_margin = $this->y_top_margin + $this->y_bot_margin;

        return;
    }


    /*!
     * Set the margins in pixels (left, right, top, bottom)
     */
    function SetMarginsPixels($which_lm, $which_rm, $which_tm, $which_bm)
    { 

        $this->x_left_margin = $which_lm;
        $this->x_right_margin = $which_rm;
        $this->x_tot_margin = $which_lm + $which_rm;

        $this->y_top_margin = $which_tm;
        $this->y_bot_margin = $which_bm;
        $this->y_tot_margin = $which_tm + $which_bm;

        $this->SetPlotAreaPixels();

        return;
    }


    /*!
     * Sets the limits for the plot area. If no arguments are supplied, uses
     * values calculated from CalcMargins();
     * Like in GD, (0,0) is upper left
     *
     * This resets the scale if SetPlotAreaWorld() was already called
     */
    function SetPlotAreaPixels($x1=NULL, $y1=NULL, $x2=NULL, $y2=NULL) 
    {
        if ($x2 && $y2) {
            $this->plot_area = array($x1, $y1, $x2, $y2);
        } else {
            if (! isset($this->x_tot_margin))
                $this->CalcMargins();

            $this->plot_area = array($this->x_left_margin, $this->y_top_margin,
                                     $this->image_width - $this->x_right_margin,
                                     $this->image_height - $this->y_bot_margin);
        }
        $this->plot_area_width = $this->plot_area[2] - $this->plot_area[0];
        $this->plot_area_height = $this->plot_area[3] - $this->plot_area[1];

        // Reset the scale with the new plot area.
        if (isset($this->plot_max_x))
            $this->CalcTranslation();

        return TRUE;

    }


    /*!
     * Sets minimum and maximum x and y values in the plot using FindDataLimits()
     * or from the supplied parameters, if any.
     *
     * This resets the scale if SetPlotAreaPixels() was already called
     */
    function SetPlotAreaWorld($xmin=NULL, $ymin=NULL, $xmax=NULL, $ymax=NULL) 
    {
        if (! isset($this->data_limits_done)) { // For automatic setting of data we need data limits
            $this->FindDataLimits() ;
        }
 
        if ($xmin === NULL || $xmin === '') {
            if ($this->data_type == 'text-data')  // Valid for data without X values only.
                $xmin = 0;
            else
                $xmin = $this->min_x;
        }
        if ($xmax === NULL || $xmax === '') {
            if ($this->data_type == 'text-data')  // Valid for data without X values only.
                $xmax = $this->max_x + 1;
            else
                $xmax = $this->max_x;
        }

        // Leave room above and below the highest and lowest data points.
        
        if ($ymin === NULL || $ymin === '') {
            if ($this->min_y < 0)
                $ymin = ceil($this->min_y * 1.1);
            else
                $ymin = floor($this->min_y * 0.9);
        }    
        if ($ymax === NULL || $ymax === '') {
            if ($this->max_y < 0)
                $ymax = floor($this->max_y * 0.9);
            else
                $ymax = ceil($this->max_y * 1.1);
        }
        
        // Error checking
        
        if ($ymin == $ymax)     // Minimum height
            $ymax += 1;

        if ($this->yscale_type == 'log') {
            if ($ymin <= 0) { 
                $ymin = 1;
            }
            if ($ymax <= 0) {
                $this->PrintError('SetPlotAreaWorld(): Log plots need data greater than 0');
                return FALSE;
            }
        }
        
        if ($ymax <= $ymin) {
            $this->DrawError('SetPlotAreaWorld(): Error in data - max not greater than min');
            return FALSE;
        }
       
      
        // Reset (if it was already set) the scale with the new maxs and mins
      
        $this->plot_min_x = $xmin;
        $this->plot_max_x = $xmax;
        $this->plot_min_y = $ymin;
        $this->plot_max_y = $ymax;

        if (isset($this->plot_area_width)) {
            $this->CalcTranslation();
        }

        return TRUE;
    } //function SetPlotAreaWorld


    /*!
     * For bar plots, which have equally spaced x variables.
     */
    function CalcBarWidths() 
    {
        $group_width = ($this->plot_area[2] - $this->plot_area[0]) /
                      $this->num_data_rows * $this->group_frac_width;
        if ($this->plot_type == 'bars') {
            $this->record_bar_width = $group_width / $this->records_per_group;
        } else if ($this->plot_type == 'stackedbars') {
            $this->record_bar_width = $group_width;
        }            
        $this->data_group_space = $group_width / 2;
        return TRUE;
    }

    /*!
     * Calculates scaling stuff...
     */
    function CalcTranslation()
    {
        if ($this->plot_max_x - $this->plot_min_x == 0) { // Check for div by 0
            $this->xscale = 0;
        } else {
            if ($this->xscale_type == 'log') {
                $this->xscale = ($this->plot_area_width)/(log10($this->plot_max_x) - log10($this->plot_min_x));
            } else {
                $this->xscale = ($this->plot_area_width)/($this->plot_max_x - $this->plot_min_x);
            }
        }

        if ($this->plot_max_y - $this->plot_min_y == 0) { // Check for div by 0
            $this->yscale = 0;
        } else {
            if ($this->yscale_type == 'log') {
                $this->yscale = ($this->plot_area_height)/(log10($this->plot_max_y) - log10($this->plot_min_y));
            } else {
                $this->yscale = ($this->plot_area_height)/($this->plot_max_y - $this->plot_min_y);
            }
        }
        // GD defines x = 0 at left and y = 0 at TOP so -/+ respectively
        if ($this->xscale_type == 'log') {
            $this->plot_origin_x = $this->plot_area[0] - ($this->xscale * log10($this->plot_min_x) );
        } else {
            $this->plot_origin_x = $this->plot_area[0] - ($this->xscale * $this->plot_min_x);
        }
        if ($this->yscale_type == 'log') {
            $this->plot_origin_y = $this->plot_area[3] + ($this->yscale * log10($this->plot_min_y));
        } else { 
            $this->plot_origin_y = $this->plot_area[3] + ($this->yscale * $this->plot_min_y);
        }

        $this->scale_is_set = TRUE;

        /************** FIXME?? *************/
        // There should be a better place for this.

        // User provided y axis position?
        if ($this->y_axis_position != '') {
            // Make sure we draw our axis inside the plot
            $this->y_axis_position = ($this->y_axis_position < $this->plot_min_x)
                                     ? $this->plot_min_x : $this->y_axis_position;
            $this->y_axis_position = ($this->y_axis_position > $this->plot_max_x)
                                     ? $this->plot_max_x : $this->y_axis_position;
            $this->y_axis_x_pixels = $this->xtr($this->y_axis_position);
        } else {
            // Default to left axis
            $this->y_axis_x_pixels = $this->xtr($this->plot_min_x);
        }
        // User provided x axis position?
        if ($this->x_axis_position != '') {
            // Make sure we draw our axis inside the plot
            $this->x_axis_position = ($this->x_axis_position < $this->plot_min_y)
                                     ? $this->plot_min_y : $this->x_axis_position;
            $this->x_axis_position = ($this->x_axis_position > $this->plot_max_y)
                                     ? $this->plot_max_y : $this->x_axis_position;
            $this->x_axis_y_pixels = $this->ytr($this->x_axis_position);
        } else { 
            if ($this->yscale_type == 'log')
                $this->x_axis_y_pixels = $this->ytr(1);
            else
                // Default to axis at 0 or plot_min_y (should be 0 anyway, from SetPlotAreaWorld())
                $this->x_axis_y_pixels = ($this->plot_min_y <= 0) && (0 <= $this->plot_max_y) 
                                         ? $this->ytr(0) : $this->ytr($this->plot_min_y);
        }

    } // function CalcTranslation()


    /*!
     * Translate X world coordinate into pixel coordinate
     * Needs values calculated by _CalcTranslation()
     */
    function xtr($x_world) 
    {
        //$x_pixels =  $this->x_left_margin + ($this->image_width - $this->x_tot_margin)*
        //      (($x_world - $this->plot_min_x) / ($this->plot_max_x - $this->plot_min_x)) ;
        //which with a little bit of math reduces to ...
        if ($this->xscale_type == 'log') { 
            $x_pixels = $this->plot_origin_x + log10($x_world) * $this->xscale ;
        } else { 
            $x_pixels = $this->plot_origin_x + $x_world * $this->xscale ;
        }
        return round($x_pixels);
    }


    /*!
     * Translate Y world coordinate into pixel coordinate.
     * Needs values calculated by _CalcTranslation()
     */
    function ytr($y_world) 
    {
        if ($this->yscale_type == 'log') {
            //minus because GD defines y = 0 at top. doh!
            $y_pixels =  $this->plot_origin_y - log10($y_world) * $this->yscale ;
        } else { 
            $y_pixels =  $this->plot_origin_y - $y_world * $this->yscale ;  
        }
        return round($y_pixels);
    }

    /*!
     * Formats a tick or data label.
     *
     * \note Time formatting suggested by Marlin Viss
     */
    function FormatLabel($which_pos, $which_lab)
    {
        switch ($which_pos) {
        case 'x':
        case 'plotx':
            switch ($this->x_label_type) {
            case 'title':
                $lab = @ $this->data[$which_lab][0];
                break;
            case 'data':
                $lab = number_format($which_lab, $this->x_precision, '.', ',').$this->data_units_text;
                break;
            case 'time':
                $lab = strftime($this->x_time_format, $which_lab);
                break;
            default:
                // Unchanged from whatever format it is passed in
                $lab = $which_lab;
            break;
            }
            break;
        case 'y':
        case 'ploty':
            switch ($this->y_label_type) {
            case 'data':
                $lab = number_format($which_lab, $this->y_precision, '.', ',').$this->data_units_text;
                break;
            case 'time':
                $lab = strftime($this->y_time_format, $which_lab);
                break;
            default:
                // Unchanged from whatever format it is passed in
                $lab = $which_lab;
                break;
            }
            break;
        default:
            $this->PrintError("FormatLabel(): Unknown label type $which_type");
            return NULL;
        }

        return $lab;
    } //function FormatLabel



/////////////////////////////////////////////    
///////////////                         TICKS
/////////////////////////////////////////////    

    /*!
     * Use either this or SetNumXTicks() to set where to place x tick marks
     */
    function SetXTickIncrement($which_ti=NULL)
    {
        if ($which_ti) {
            $this->x_tick_inc = $which_ti;  //world coordinates
        } else {
            if (! isset($this->data_limits_done)) {
                $this->FindDataLimits();  //Get maxima and minima for scaling
            }
            $this->x_tick_inc =  ($this->plot_max_x  - $this->plot_min_x  )/10;
        }
        $this->num_x_ticks = ''; //either use num_y_ticks or y_tick_inc, not both
        return TRUE;
    }

    /*!
     * Use either this or SetNumYTicks() to set where to place y tick marks
     */
    function SetYTickIncrement($which_ti=NULL)
    {
        if ($which_ti) {
            $this->y_tick_inc = $which_ti;  //world coordinates
        } else {
            if (! isset($this->data_limits_done)) {
                $this->FindDataLimits();  //Get maxima and minima for scaling
            }
            if (! isset($this->plot_max_y))
                $this->SetPlotAreaWorld();

            $this->y_tick_inc =  ($this->plot_max_y  - $this->plot_min_y  )/10;
        }
        $this->num_y_ticks = ''; //either use num_y_ticks or y_tick_inc, not both
        return TRUE;
    }


    function SetNumXTicks($which_nt) 
    {
        $this->num_x_ticks = $which_nt;
        $this->x_tick_inc = '';  //either use num_x_ticks or x_tick_inc, not both
        return TRUE;
    }

    function SetNumYTicks($which_nt) 
    {
        $this->num_y_ticks = $which_nt;
        $this->y_tick_inc = '';  //either use num_y_ticks or y_tick_inc, not both
        return TRUE;
    }

    /*!
     *
     */
    function SetYTickPos($which_tp) 
    { 
        $this->y_tick_pos = $this->CheckOption($which_tp, 'plotleft, plotright, both, yaxis, none', __FUNCTION__);
        return TRUE;
    }
    /*!
     *
     */
    function SetXTickPos($which_tp)
    { 
        $this->x_tick_pos = $this->CheckOption($which_tp, 'plotdown, plotup, both, xaxis, none', __FUNCTION__);
        return TRUE;
    }

    /*!
     * \param skip bool
     */ 
    function SetSkipTopTick($skip)
    {
        $this->skip_top_tick = (bool)$skip;
        return TRUE;
    }

    /*!
     * \param skip bool
     */
    function SetSkipBottomTick($skip) 
    {
        $this->skip_bottom_tick = (bool)$skip;
        return TRUE;
    }

    /*!
     * \param skip bool
     */ 
    function SetSkipLeftTick($skip)
    {
        $this->skip_left_tick = (bool)$skip;
        return TRUE;
    }

    /*!
     * \param skip bool
     */
    function SetSkipRightTick($skip)
    {
        $this->skip_right_tick = (bool)$skip;
        return TRUE;
    }

    function SetXTickLength($which_xln)
    {
        $this->x_tick_length = $which_xln;
        return TRUE;
    }

    function SetYTickLength($which_yln)
    {
        $this->y_tick_length = $which_yln;
        return TRUE;
    }

    function SetXTickCrossing($which_xc)
    {
        $this->x_tick_cross = $which_xc;
        return TRUE;
    }

    function SetYTickCrossing($which_yc)
    {
        $this->y_tick_cross = $which_yc;
        return TRUE;
    }


/////////////////////////////////////////////
////////////////////          GENERIC DRAWING
/////////////////////////////////////////////

    /*!
     * Fills the background.
     */
    function DrawBackground()
    {
        // Don't draw this twice if drawing two plots on one image
        if (! $this->background_done) {
            if (isset($this->bgimg)) {    // If bgimg is defined, use it
                $this->tile_img($this->bgimg, 0, 0, $this->image_width, $this->image_height, $this->bgmode);
            } else {                        // Else use solid color
                ImageFilledRectangle($this->img, 0, 0, $this->image_width, $this->image_height,
                                     $this->ndx_bg_color);
            }
            $this->background_done = TRUE;
            return TRUE;        // Done
        }
        return FALSE;           // Nothing done
    }


    /*!
     * Fills the plot area background.
     */
    function DrawPlotAreaBackground()
    {
        if (isset($this->plotbgimg)) {
            $this->tile_img($this->plotbgimg, $this->plot_area[0], $this->plot_area[1],
                            $this->plot_area_width, $this->plot_area_height, $this->plotbgmode);
        }
        else {
            if ($this->draw_plot_area_background) {
                ImageFilledRectangle($this->img, $this->plot_area[0], $this->plot_area[1],
                                     $this->plot_area[2], $this->plot_area[3], $this->ndx_plot_bg_color);
            }
        }

        return TRUE;
    }


    /*!
     * Tiles an image at some given coordinates.
     *
     * \param $file   string Filename of the picture to be used as tile.
     * \param $xorig  int    X coordinate of the plot where the tile is to begin.
     * \param $yorig  int    Y coordinate of the plot where the tile is to begin.
     * \param $width  int    Width of the area to be tiled.
     * \param $height int    Height of the area to be tiled.
     * \param $mode   string One of 'centeredtile', 'tile', 'scale'.
     */
    function tile_img($file, $xorig, $yorig, $width, $height, $mode)
    {
        $size = getimagesize($file);
        $input_format = $size[2];

        switch($input_format) {
        case 1:
            $im = @ imagecreatefromGIF ($file);
            if (! $im) {
                $this->PrintError("tile_img:() Unable to open $file as a GIF.");
                return FALSE;
            }
            break;
        case 2:
            $im = @ imagecreatefromJPEG ($file);
            if (! $im) {
                $this->PrintError("tile_img(): Unable to open $file as a JPG.");
                return FALSE;
            }
            break;
        case 3:
            $im = @ imagecreatefromPNG ($file);
            if (! $im) {
                $this->PrintError("tile_img(): Unable to open $file as a PNG.");
                return FALSE;
            }
            break;
        default:
            $this->PrintError('tile_img(): Please select a gif, jpg, or png image.');
            return FALSE;
            break;
        }


        if ($mode == 'scale') {
            imagecopyresized($this->img, $im, $xorig, $yorig, 0, 0, $width, $height, $size[0],$size[1]);
            return TRUE;
        } else if ($mode == 'centeredtile') {
            $x0 = - floor($size[0]/2);   // Make the tile look better
            $y0 = - floor($size[1]/2);
        } else if ($mode = 'tile') {
            $x0 = 0;
            $y0 = 0;
        }

        // Actually draw the tile

        // But first on a temporal image.
        $tmp = ImageCreate($width, $height);
        if (! $tmp)
            $this->PrintError('tile_img(): Could not create image resource.');

        for ($x = $x0; $x < $width; $x += $size[0])
            for ($y = $y0; $y < $height; $y += $size[1])
                imagecopy($tmp, $im, $x, $y, 0, 0, $size[0], $size[1]);

        // Copy the temporal image onto the final one.
        imagecopy($this->img, $tmp, $xorig, $yorig, 0,0, $width, $height);

        // Free resources
        imagedestroy($tmp);
        imagedestroy($im);

        return TRUE;
    }  // function tile_img


    /*!
     * Draws a border around the final image.
     */
    function DrawImageBorder()
    {
        switch ($this->image_border_type) {
        case 'raised':
            ImageLine($this->img, 0, 0, $this->image_width-1, 0, $this->ndx_i_border);
            ImageLine($this->img, 1, 1, $this->image_width-2, 1, $this->ndx_i_border);
            ImageLine($this->img, 0, 0, 0, $this->image_height-1, $this->ndx_i_border);
            ImageLine($this->img, 1, 1, 1, $this->image_height-2, $this->ndx_i_border);
            ImageLine($this->img, $this->image_width-1, 0, $this->image_width-1,
                      $this->image_height-1, $this->ndx_i_border_dark);
            ImageLine($this->img, 0, $this->image_height-1, $this->image_width-1,
                      $this->image_height-1, $this->ndx_i_border_dark);
            ImageLine($this->img, $this->image_width-2, 1, $this->image_width-2,
                      $this->image_height-2, $this->ndx_i_border_dark);
            ImageLine($this->img, 1, $this->image_height-2, $this->image_width-2,
                      $this->image_height-2, $this->ndx_i_border_dark);
            break;
        case 'plain':
            ImageLine($this->img, 0, 0, $this->image_width, 0, $this->ndx_i_border_dark);
            ImageLine($this->img, $this->image_width-1, 0, $this->image_width-1,
                      $this->image_height, $this->ndx_i_border_dark);
            ImageLine($this->img, $this->image_width-1, $this->image_height-1, 0, $this->image_height-1,
                      $this->ndx_i_border_dark);
            ImageLine($this->img, 0, 0, 0, $this->image_height, $this->ndx_i_border_dark);
            break;
        case 'none':
            break;
        default:
            $this->DrawError("DrawImageBorder(): unknown image_border_type: '$this->image_border_type'");
            return FALSE;
        }
        return TRUE;
    }


    /*!
     * Adds the title to the graph.
     */
    function DrawTitle() 
    {
        // Center of the plot area
        //$xpos = ($this->plot_area[0] + $this->plot_area_width )/ 2;

        // Center of the image:
        $xpos = $this->image_width / 2;

        // Place it at almost at the top
        $ypos = $this->safe_margin;

        $this->DrawText($this->title_font, $this->title_angle, $xpos, $ypos,
                        $this->ndx_title_color, $this->title_txt, 'center', 'bottom'); 

        return TRUE; 

    }


    /*!
     * Draws the X-Axis Title
     */
    function DrawXTitle()
    {
        if ($this->x_title_pos == 'none')
            return;

        // Center of the plot
        $xpos = ($this->plot_area[2] + $this->plot_area[0]) / 2;

        // Upper title
        if ($this->x_title_pos == 'plotup' || $this->x_title_pos == 'both') {
            $ypos = $this->safe_margin + $this->title_height + $this->safe_margin;
            $this->DrawText($this->x_title_font, $this->x_title_angle,
                            $xpos, $ypos, $this->ndx_title_color, $this->x_title_txt, 'center');
        }
        // Lower title
        if ($this->x_title_pos == 'plotdown' || $this->x_title_pos == 'both') {
            $ypos = $this->image_height - $this->x_title_height - $this->safe_margin;
            $this->DrawText($this->x_title_font, $this->x_title_angle,
                            $xpos, $ypos, $this->ndx_title_color, $this->x_title_txt, 'center');
        }
        return TRUE;
    }

    /*!
     * Draws the Y-Axis Title
     */
    function DrawYTitle()
    {
        if ($this->y_title_pos == 'none')
            return;

        // Center the title vertically to the plot
        $ypos = ($this->plot_area[3] + $this->plot_area[1]) / 2;

        if ($this->y_title_pos == 'plotleft' || $this->y_title_pos == 'both') {
            $xpos = $this->safe_margin;
            $this->DrawText($this->y_title_font, 90, $xpos, $ypos, $this->ndx_title_color,
                            $this->y_title_txt, 'left', 'center');
        }
        if ($this->y_title_pos == 'plotright' || $this->y_title_pos == 'both') {
            $xpos = $this->image_width - $this->safe_margin - $this->y_title_width - $this->safe_margin;
            $this->DrawText($this->y_title_font, 90, $xpos, $ypos, $this->ndx_title_color,
                            $this->y_title_txt, 'left', 'center');
        }

        return TRUE;
    }


    /*
     * \note Horizontal grid lines overwrite horizontal axis with y=0, so call this first, then DrawXAxis()
     */
    function DrawYAxis()
    {
        // Draw ticks, labels and grid, if any
        $this->DrawYTicks();

        // Draw Y axis at X = y_axis_x_pixels
        ImageLine($this->img, $this->y_axis_x_pixels, $this->plot_area[1],
                  $this->y_axis_x_pixels, $this->plot_area[3], $this->ndx_grid_color);

        return TRUE;
    }

    /*
     *
     */
    function DrawXAxis()
    {
        // Draw ticks, labels and grid
        $this->DrawXTicks();

        /* This tick and label tend to overlap with regular Y Axis labels,
         * as Mike Pullen pointed out.
         *
        //Draw Tick and Label for X axis
        if (! $this->skip_bottom_tick) {
            $ylab =$this->FormatLabel('y', $this->x_axis_position);
            $this->DrawYTick($ylab, $this->x_axis_y_pixels);
        }
        */
        //Draw X Axis at Y = x_axis_y_pixels
        ImageLine($this->img, $this->plot_area[0]+1, $this->x_axis_y_pixels,
                  $this->plot_area[2]-1, $this->x_axis_y_pixels, $this->ndx_grid_color);

        return TRUE;
    }

    /*!
     * Draw Just one Tick, called from DrawYTicks() and DrawXAxis()
     * TODO? Move this inside DrawYTicks() and Modify DrawXAxis() ?
     */
    function DrawYTick($which_ylab, $which_ypix)
    {
        // Ticks on Y axis
        if ($this->y_tick_pos == 'yaxis') {
            ImageLine($this->img, $this->y_axis_x_pixels - $this->y_tick_length, $which_ypix,
                      $this->y_axis_x_pixels + $this->y_tick_cross, $which_ypix,
                      $this->ndx_tick_color);
        }

        // Labels on Y axis
        if ($this->y_tick_label_pos == 'yaxis') {
            $this->DrawText($this->y_label_font, $this->y_label_angle,
                            $this->y_axis_x_pixels - $this->y_tick_length * 1.5, $which_ypix,
                            $this->ndx_text_color, $which_ylab, 'right', 'center');
        }

        // Ticks to the left of the Plot Area
        if (($this->y_tick_pos == 'plotleft') || ($this->y_tick_pos == 'both') ) {
            ImageLine($this->img, $this->plot_area[0] - $this->y_tick_length,
                      $which_ypix, $this->plot_area[0] + $this->y_tick_cross,
                      $which_ypix, $this->ndx_tick_color);
        }

        // Ticks to the right of the Plot Area
        if (($this->y_tick_pos == 'plotright') || ($this->y_tick_pos == 'both') ) {
            ImageLine($this->img, ($this->plot_area[2] + $this->y_tick_length),
                      $which_ypix, $this->plot_area[2] - $this->y_tick_cross,
                      $which_ypix, $this->ndx_tick_color);
        }

        // Labels to the left of the plot area
        if ($this->y_tick_label_pos == 'plotleft' || $this->y_tick_label_pos == 'both') {
            $this->DrawText($this->y_label_font, $this->y_label_angle,
                            $this->plot_area[0] - $this->y_tick_length * 1.5, $which_ypix,
                            $this->ndx_text_color, $which_ylab, 'right', 'center');
        }
        // Labels to the right of the plot area
        if ($this->y_tick_label_pos == 'plotright' || $this->y_tick_label_pos == 'both') {
            $this->DrawText($this->y_label_font, $this->y_label_angle,
                            $this->plot_area[2] + $this->y_tick_length * 1.5, $which_ypix,
                            $this->ndx_text_color, $which_ylab, 'left', 'center');
        }
   } // Function DrawYTick()


    /*!
     * Draws Grid, Ticks and Tick Labels along Y-Axis
     * Ticks and ticklabels can be left of plot only, right of plot only,
     * both on the left and right of plot, or crossing a user defined Y-axis
     * TODO: marks at whole numbers (-10, 10, 20, 30 ...) no matter where the plot begins (-3, 4.7, etc.)
     */
    function DrawYTicks()
    {
        // Sets the line style for IMG_COLOR_STYLED lines (grid)
        if ($this->dashed_grid) {
            $this->SetDashedStyle($this->ndx_light_grid_color);
            $style = IMG_COLOR_STYLED;
        } else {
            $style = $this->ndx_light_grid_color;
        }

        // maxy is always > miny so delta_y is always positive
        if ($this->y_tick_inc) {
            $delta_y = $this->y_tick_inc;
        } elseif ($this->num_y_ticks) {
            $delta_y = ($this->plot_max_y - $this->plot_min_y) / $this->num_y_ticks;
        } else {
            $delta_y = ($this->plot_max_y - $this->plot_min_y) / 10 ;
        }

        // NOTE: When working with floats, because of approximations when adding $delta_y,
        // $y_tmp never equals $y_end  at the for loop, so one spurious line would  get drawn where
        // not for the substraction to $y_end here.
        $y_tmp = (double)$this->plot_min_y;
        $y_end = (double)$this->plot_max_y - ($delta_y/2);

        if ($this->skip_bottom_tick)
            $y_tmp += $delta_y;

        if ($this->skip_top_tick)
            $y_end -= $delta_y;

        for (;$y_tmp < $y_end; $y_tmp += $delta_y) {
            $ylab = $this->FormatLabel('y', $y_tmp);
            $y_pixels = $this->ytr($y_tmp);

            // Horizontal grid line
            if ($this->draw_y_grid) {
                ImageLine($this->img, $this->plot_area[0]+1, $y_pixels, $this->plot_area[2]-1, $y_pixels, $style);
            }

            // Draw ticks
            $this->DrawYTick($ylab, $y_pixels);
        }
        return TRUE;
    } // function DrawYTicks


    /*!
     * Draws Grid, Ticks and Tick Labels along X-Axis
     * Ticks and tick labels can be down of plot only, up of plot only,
     * both on up and down of plot, or crossing a user defined X-axis 
     *
     * \note Original vertical code submitted by Marlin Viss
     */
    function DrawXTicks() 
    {
        // Sets the line style for IMG_COLOR_STYLED lines (grid)
        if ($this->dashed_grid) {
            $this->SetDashedStyle($this->ndx_light_grid_color);
            $style = IMG_COLOR_STYLED;
        } else {
            $style = $this->ndx_light_grid_color;
        }

        // Calculate x increment between ticks
        if ($this->x_tick_inc) {
            $delta_x = $this->x_tick_inc;
        } elseif ($this->num_x_ticks) {
            $delta_x = ($this->plot_max_x - $this->plot_min_x) / $this->num_x_ticks;
        } else {
            $delta_x =($this->plot_max_x - $this->plot_min_x) / 10 ;
        }

        // NOTE: When working with decimals, because of approximations when adding $delta_x,
        // $x_tmp never equals $x_end  at the for loop, so one spurious line would  get drawn where
        // not for the substraction to $x_end here.
        $x_tmp = (double)$this->plot_min_x;
        $x_end = (double)$this->plot_max_x - ($delta_x/2);

        // Should the leftmost tick be drawn?
        if ($this->skip_left_tick)
            $x_tmp += $delta_x;

        // And the rightmost?
        if (! $this->skip_right_tick)
            $x_end += $delta_x;

        for (;$x_tmp < $x_end; $x_tmp += $delta_x) {
            $xlab = $this->FormatLabel('x', $x_tmp);
            $x_pixels = $this->xtr($x_tmp);

            // Vertical grid lines
            if ($this->draw_x_grid) {
                ImageLine($this->img, $x_pixels, $this->plot_area[1], $x_pixels, $this->plot_area[3], $style);
            }

            // Tick on X Axis
            if ($this->x_tick_pos == 'xaxis') {

                ImageLine($this->img, $x_pixels, $this->x_axis_y_pixels - $this->x_tick_cross,
                          $x_pixels, $this->x_axis_y_pixels + $this->x_tick_length, $this->ndx_tick_color);
            }

            // Label on X axis
            if ($this->x_tick_label_pos == 'xaxis') {
                 $this->DrawText($this->x_label_font, $this->x_label_angle, $x_pixels,
                                $this->x_axis_y_pixels + $this->x_tick_length*1.5, $this->ndx_text_color, 
                                $xlab, 'center', 'bottom');
            }              

            // Top of the plot area tick
            if ($this->x_tick_pos == 'plotup' || $this->x_tick_pos == 'both') {
                ImageLine($this->img, $x_pixels, $this->plot_area[1] - $this->x_tick_length,
                          $x_pixels, $this->plot_area[1] + $this->x_tick_cross, $this->ndx_tick_color);
            }
            // Bottom of the plot area tick
            if ($this->x_tick_pos == 'plotdown' || $this->x_tick_pos == 'both') {
                ImageLine($this->img, $x_pixels, $this->plot_area[3] + $this->x_tick_length,
                          $x_pixels, $this->plot_area[3] - $this->x_tick_cross, $this->ndx_tick_color);
            }

            // Top of the plot area tick label
            if ($this->x_tick_label_pos == 'plotup' || $this->x_tick_label_pos == 'both') {
                $this->DrawText($this->x_label_font, $this->x_label_angle, $x_pixels, 
                                $this->plot_area[1] - $this->x_tick_length*1.5, $this->ndx_text_color, 
                                $xlab, 'center', 'top');
            }

            // Bottom of the plot area tick label
            if ($this->x_tick_label_pos == 'plotdown' || $this->x_tick_label_pos == 'both') {
                $this->DrawText($this->x_label_font, $this->x_label_angle, $x_pixels,
                                $this->plot_area[3] + $this->x_tick_length*1.5, $this->ndx_text_color,
                                $xlab, 'center', 'bottom');
            }
        }
        return;
    } // function DrawXTicks


    /*!
     * 
     */
    function DrawPlotBorder()
    {
        switch ($this->plot_border_type) {
        case 'left':    // for past compatibility
        case 'plotleft':
            ImageLine($this->img, $this->plot_area[0], $this->ytr($this->plot_min_y),
                      $this->plot_area[0], $this->ytr($this->plot_max_y), $this->ndx_grid_color);
            break;
        case 'right':
        case 'plotright':
            ImageLine($this->img, $this->plot_area[2], $this->ytr($this->plot_min_y),
                      $this->plot_area[2], $this->ytr($this->plot_max_y), $this->ndx_grid_color);
            break;
        case 'both':
        case 'sides':
             ImageLine($this->img, $this->plot_area[0], $this->ytr($this->plot_min_y),
                      $this->plot_area[0], $this->ytr($this->plot_max_y), $this->ndx_grid_color);
            ImageLine($this->img, $this->plot_area[2], $this->ytr($this->plot_min_y),
                      $this->plot_area[2], $this->ytr($this->plot_max_y), $this->ndx_grid_color);
            break;
        case 'none':
            //Draw No Border
            break;
        case 'full':
        default:
            ImageRectangle($this->img, $this->plot_area[0], $this->ytr($this->plot_min_y),
                           $this->plot_area[2], $this->ytr($this->plot_max_y), $this->ndx_grid_color);
            break;
        }
        return TRUE;
    }


    /*!
     * Draws the data label associated with a point in the plot.
     * This is different from x_labels drawn by DrawXTicks() and care
     * should be taken not to draw both, as they'd probably overlap.
     * Calling of this function in DrawLines(), etc is decided after x_data_label_pos value.
     * Leave the last parameter out, to avoid the drawing of vertical lines, no matter
     * what the setting is (for plots that need it, like DrawSquared())
     */
    function DrawXDataLabel($xlab, $xpos, $row=FALSE)
    {
        // FIXME!! not working...
        if (($this->_x_label_cnt++ % $this->x_label_inc) != 0)
            return;

        $xlab = $this->FormatLabel('x', $xlab);

        // Labels below the plot area
        if ($this->x_data_label_pos == 'plotdown' || $this->x_data_label_pos == 'both')
            $this->DrawText($this->x_label_font, $this->x_label_angle, $xpos,
                            $this->plot_area[3] + $this->x_tick_length,
                            $this->ndx_text_color, $xlab, 'center', 'bottom');

        // Labels above the plot area
        if ($this->x_data_label_pos == 'plotup' || $this->x_data_label_pos == 'both')
            $this->DrawText($this->x_label_font, $this->x_label_angle, $xpos,
                            $this->plot_area[1] - $this->x_tick_length ,
                            $this->ndx_text_color, $xlab, 'center', 'top');

        if ($row && $this->draw_x_data_label_lines)
            $this->DrawXDataLine($xpos, $row);
    }

    /*!
     * Draws Vertical lines from data points up and down.
     * Which lines are drawn depends on the value of x_data_label_pos,
     * and whether this is at all done or not, on draw_x_data_label_lines
     *
     * \param xpos int position in pixels of the line.
     * \param row int index of the data row being drawn.
     */
    function DrawXDataLine($xpos, $row)
    {
        // Sets the line style for IMG_COLOR_STYLED lines (grid)
        if($this->dashed_grid) {
            $this->SetDashedStyle($this->ndx_light_grid_color);
            $style = IMG_COLOR_STYLED;
        } else {
            $style = $this->ndx_light_grid_color;
        }

        // Lines from the bottom up
        if ($this->x_data_label_pos == 'both') {
            ImageLine($this->img, $xpos, $this->plot_area[3], $xpos, $this->plot_area[1], $style);
        }
        // Lines coming from the bottom of the plot
        else if ($this->x_data_label_pos == 'plotdown') {
            // See FindDataLimits() to see why 'MAXY' index.
            $ypos = $this->ytr($this->data[$row][MAXY]);
            ImageLine($this->img, $xpos, $ypos, $xpos, $this->plot_area[3], $style);
        }
        // Lines coming from the top of the plot
        else if ($this->x_data_label_pos == 'plotup') {
            // See FindDataLimits() to see why 'MINY' index.
            $ypos = $this->ytr($this->data[$row][MINY]);
            ImageLine($this->img, $xpos, $this->plot_area[1], $xpos, $ypos, $style);
        }
    } 
    
/*    
    function DrawPlotLabel($xlab, $xpos, $ypos) 
    {
        $this->DrawText($this->x_label_font, $this->x_label_angle, $xpos, $this
*/

    /*!
     * Draws the graph legend
     *
     * \note Base code submitted by Marlin Viss
     * FIXME: maximum label length should be calculated more accurately for TT fonts
     *        Performing a BBox calculation for every legend element, for example.
     */
    function DrawLegend($which_x1, $which_y1, $which_boxtype)
    {
        // Find maximum legend label length
        $max_len = 0;
        foreach ($this->legend as $leg) {
            $len = strlen($leg);
            $max_len = ($len > $max_len) ? $len : $max_len;
        }
        $max_len += 5;          // Leave room for the boxes and margins

        /////// Calculate legend labels sizes:  FIXME - dirty hack - FIXME
        // TTF:
        if ($this->use_ttf) {
            $size = $this->TTFBBoxSize($this->legend_font['size'], 0,
                                       $this->legend_font['font'], '_');
            $char_w = $size[0];

            $size = $this->TTFBBoxSize($this->legend_font['size'], 0,
                                       $this->legend_font['font'], '|');
            $char_h = $size[1];                                       
        } 
        // Fixed fonts:
        else {
            $char_w = $this->legend_font['width'];
            $char_h = $this->legend_font['height'];
        }

        $v_margin = $char_h/2;                         // Between vertical borders and labels
        $dot_height = $char_h + $this->line_spacing;   // Height of the small colored boxes
        $width = $char_w * $max_len;

        //////// Calculate box size
        // upper Left
        if ( (! $which_x1) || (! $which_y1) ) {
            $box_start_x = $this->plot_area[2] - $width;
            $box_start_y = $this->plot_area[1] + 5;
        } else { 
            $box_start_x = $which_x1;
            $box_start_y = $which_y1;
        }

        // Lower right corner
        $box_end_y = $box_start_y + $dot_height*(count($this->legend)) + 2*$v_margin; 
        $box_end_x = $box_start_x + $width - 5;


        // Draw outer box
        ImageFilledRectangle($this->img, $box_start_x, $box_start_y, $box_end_x, $box_end_y, $this->ndx_bg_color);
        ImageRectangle($this->img, $box_start_x, $box_start_y, $box_end_x, $box_end_y, $this->ndx_grid_color);

        $color_index = 0;
        $max_color_index = count($this->ndx_data_colors) - 1;

        $dot_left_x = $box_end_x - $char_w * 2;
        $dot_right_x = $box_end_x - $char_w;
        $y_pos = $box_start_y + $v_margin;

        foreach ($this->legend as $leg) {
            // Text right aligned to the little box
            $this->DrawText($this->legend_font, 0, $dot_left_x - $char_w, $y_pos, 
                            $this->ndx_text_color, $leg, 'right');
            // Draw a box in the data color
            ImageFilledRectangle($this->img, $dot_left_x, $y_pos + 1, $dot_right_x,
                                 $y_pos + $dot_height-1, $this->ndx_data_colors[$color_index]);
            // Draw a rectangle around the box
            ImageRectangle($this->img, $dot_left_x, $y_pos + 1, $dot_right_x,
                           $y_pos + $dot_height-1, $this->ndx_text_color);

            $y_pos += $char_h + $this->line_spacing;

            $color_index++;
            if ($color_index > $max_color_index) 
                $color_index = 0;
        }
    } // Function DrawLegend()


    /*!
     * TODO Draws a legend over (or below) an axis of the plot.
     */
    function DrawAxisLegend()
    {
        // Calculate available room
        // Calculate length of all items (boxes included)
        // Calculate number of lines and room it would take. FIXME: this should be known in CalcMargins()
        // Draw.
    }

/////////////////////////////////////////////
////////////////////             PLOT DRAWING
/////////////////////////////////////////////


    /*!
     * Draws a pie chart. Data has to be 'text-data' type.
     *
     *  This can work in two ways: the classical, with a column for each sector
     *  (computes the column totals and draws the pie with that)
     *  OR
     *  Takes each row as a sector and uses it's first value. This has the added
     *  advantage of using the labels provided, which is not the case with the
     *  former method. This might prove useful for pie charts from GROUP BY sql queries
     */
    function DrawPieChart()
    {
        $xpos = $this->plot_area[0] + $this->plot_area_width/2;
        $ypos = $this->plot_area[1] + $this->plot_area_height/2;
        $diameter = min($this->plot_area_width, $this->plot_area_height);
        $radius = $diameter/2;

        // Get sum of each column? One pie slice per column
        if ($this->data_type === 'text-data') {
            for ($i = 0; $i < $this->num_data_rows; $i++) {
                for ($j = 1; $j < $this->num_recs[$i]; $j++) {      // Label ($row[0]) unused in these pie charts
                    @ $sumarr[$j] += abs($this->data[$i][$j]);      // NOTE!  sum > 0 to make pie charts
                }
            }
        }
        // Or only one column per row, one pie slice per row?
        else if ($this->data_type == 'text-data-single') {
            for ($i = 0; $i < $this->num_data_rows; $i++) {
                $legend[$i] = $this->data[$i][0];                   // Set the legend to column labels
                $sumarr[$i] = $this->data[$i][1];
            }
        }
        else if ($this->data_type == 'data-data') {
            for ($i = 0; $i < $this->num_data_rows; $i++) {
                for ($j = 2; $j < $this->num_recs[$i]; $j++) {
                    @ $sumarr[$j] += abs($this->data[$i][$j]);
                }
            }
        }
        else {
            $this->DrawError("DrawPieChart(): Data type '$this->data_type' not supported.");
            return FALSE;
        }

        $total = array_sum($sumarr);

        if ($total == 0) {
            $this->DrawError('DrawPieChart(): Empty data set');
            return FALSE;
        }

        if ($this->shading) {
            $diam2 = $diameter / 2;
        } else {
            $diam2 = $diameter;
        }
        $max_data_colors = count ($this->data_colors);

        for ($h = $this->shading; $h >= 0; $h--) {
            $color_index = 0;
            $start_angle = 0;
            $end_angle = 0;
            foreach ($sumarr as $val) {
                // For shaded pies: the last one (at the top of the "stack") has a brighter color:
                if ($h == 0)
                    $slicecol = $this->ndx_data_colors[$color_index];
                else
                    $slicecol = $this->ndx_data_dark_colors[$color_index];

                $label_txt = number_format(($val / $total * 100), $this->y_precision, '.', ', ') . '%';
                $val = 360 * ($val / $total);

                // NOTE that imagefilledarc measures angles CLOCKWISE (go figure why),
                // so the pie chart would start clockwise from 3 o'clock, would it not be
                // for the reversal of start and end angles in imagefilledarc()
                $start_angle = $end_angle;
                $end_angle += $val;
                $mid_angle = deg2rad($end_angle - ($val / 2));

                // Draw the slice
                ImageFilledArc($this->img, $xpos, $ypos+$h, $diameter, $diam2,
                               360-$end_angle, 360-$start_angle,
                               $slicecol, IMG_ARC_PIE);

                // Draw the labels only once
                if ($h == 0) {
                    // Draw the outline
                    if (! $this->shading)
                        ImageFilledArc($this->img, $xpos, $ypos+$h, $diameter, $diam2,
                                       360-$end_angle, 360-$start_angle,
                                       $this->ndx_grid_color, IMG_ARC_PIE | IMG_ARC_EDGED |IMG_ARC_NOFILL);


                    // The '* 1.2' trick is to get labels out of the pie chart so there are more
                    // chances they can be seen in small sectors.
                    $label_x = $xpos + ($diameter * 1.2 * cos($mid_angle)) * $this->label_scale_position;
                    $label_y = $ypos+$h - ($diam2 * 1.2 * sin($mid_angle)) * $this->label_scale_position;

                    $this->DrawText($this->generic_font, 0, $label_x, $label_y, $this->ndx_grid_color,
                                    $label_txt, 'center', 'center');
                }
                $color_index++;
                $color_index = $color_index % $max_data_colors;
            }   // end for
        }   // end for
    }


    /*!
     * Supported data formats: data-data-error, text-data-error (doesn't exist yet)
     * ( data comes in as array("title", x, y, error+, error-, y2, error2+, error2-, ...) )
     */
    function DrawDotsError()
    {
        $this->CheckOption($this->data_type, 'data-data-error', __FUNCTION__);

        for($row = 0, $cnt = 0; $row < $this->num_data_rows; $row++) {
            $record = 1;                                // Skip record #0 (title)

            // Do we have a value for X?
            if ($this->data_type == 'data-data-error')
                $x_now = $this->data[$row][$record++];  // Read it, advance record index
            else
                $x_now = 0.5 + $cnt++;                  // Place text-data at X = 0.5, 1.5, 2.5, etc...

            // Draw X Data labels?
            if ($this->x_data_label_pos != 'none')
                $this->DrawXDataLabel($this->data[$row][0], $x_now_pixels, $row);

            while ($record < $this->num_recs[$row]) {
                    // Y:
                    $y_now = $this->data[$row][$record];
                    $this->DrawDot($x_now, $y_now, $record, $this->ndx_data_colors[$record++]);

                    // Error +
                    $val = $this->data[$row][$record];
                    $this->DrawYErrorBar($x_now, $y_now, $val, $this->error_bar_shape,
                                         $this->ndx_error_bar_colors[$record++]);
                    // Error -
                    $val = $this->data[$row][$record];
                    $this->DrawYErrorBar($x_now, $y_now, -$val, $this->error_bar_shape,
                                         $this->ndx_error_bar_colors[$record++]);
            }
        }
    } // function DrawDotsError()


    /*
     * Supported data types:
     *  - data-data ("title", x, y1, y2, y3, ...)
     *  - text-data ("title", y1, y2, y3, ...)
     */
    function DrawDots()
    {
        $this->CheckOption($this->data_type, 'text-data, data-data', __FUNCTION__);

        for ($row = 0, $cnt = 0; $row < $this->num_data_rows; $row++) {
            $rec = 1;                    // Skip record #0 (data label)

            // Do we have a value for X?
            if ($this->data_type == 'data-data')
                $x_now = $this->data[$row][$rec++];  // Read it, advance record index
            else
                $x_now = 0.5 + $cnt++;       // Place text-data at X = 0.5, 1.5, 2.5, etc...

            $x_now_pixels = $this->xtr($x_now);

            // Draw X Data labels?
            if ($this->x_data_label_pos != 'none')
                $this->DrawXDataLabel($this->data[$row][0], $x_now_pixels, $row);

            // Proceed with Y values
            for($idx = 0;$rec < $this->num_recs[$row]; $rec++, $idx++) {
                if (is_numeric($this->data[$row][$rec])) {              // Allow for missing Y data
                    $this->DrawDot($x_now, $this->data[$row][$rec],
                                   $rec, $this->ndx_data_colors[$idx]);
                }
            }
        }
    } //function DrawDots


    /*!
     * A clean, fast routine for when you just want charts like stock volume charts
     */
    function DrawThinBarLines()
    {
        $this->CheckOption($this->data_type, 'text-data, data-data', __FUNCTION__);

        for ($row = 0, $cnt = 0; $row < $this->num_data_rows; $row++) {
            $rec = 1;                    // Skip record #0 (data label)

            // Do we have a value for X?
            if ($this->data_type == 'data-data')
                $x_now = $this->data[$row][$rec++];  // Read it, advance record index
            else
                $x_now = 0.5 + $cnt++;       // Place text-data at X = 0.5, 1.5, 2.5, etc...

            $x_now_pixels = $this->xtr($x_now);

            // Draw X Data labels?
            if ($this->x_data_label_pos != 'none')
                $this->DrawXDataLabel($this->data[$row][0], $x_now_pixels);

            // Proceed with Y values
            for($idx = 0;$rec < $this->num_recs[$row]; $rec++, $idx++) {
                if (is_numeric($this->data[$row][$rec])) {              // Allow for missing Y data 
                    ImageSetThickness($this->img, $this->line_widths[$idx]);
                    // Draws a line from user defined x axis position up to ytr($val)
                    ImageLine($this->img, $x_now_pixels, $this->x_axis_y_pixels, $x_now_pixels, 
                              $this->ytr($this->data[$row][$rec]), $this->ndx_data_colors[$idx]);
                }
            }
        }

        ImageSetThickness($this->img, 1);
    }  //function DrawThinBarLines

    /*!
     *
     */
    function DrawYErrorBar($x_world, $y_world, $error_height, $error_bar_type, $color)
    {
        /* 
        // TODO: add a parameter to show datalabels next to error bars?
        // something like this:
        if ($this->x_data_label_pos == 'plot') {
            $this->DrawText($this->error_font, 90, $x1, $y2, 
                            $color, $label, 'center', 'top');
        */

        $x1 = $this->xtr($x_world);
        $y1 = $this->ytr($y_world);
        $y2 = $this->ytr($y_world+$error_height) ;

        ImageSetThickness($this->img, $this->error_bar_line_width);
        ImageLine($this->img, $x1, $y1 , $x1, $y2, $color);

        switch ($error_bar_type) {
        case 'line':
            break;
        case 'tee':
            ImageLine($this->img, $x1-$this->error_bar_size, $y2, $x1+$this->error_bar_size, $y2, $color);
            break;
        default:
            ImageLine($this->img, $x1-$this->error_bar_size, $y2, $x1+$this->error_bar_size, $y2, $color);
            break;
        }

        ImageSetThickness($this->img, 1);
        return TRUE;
    }

    /*!
     * Draws a styled dot. Uses world coordinates.
     * Supported types: 'halfline', 'line', 'plus', 'cross', 'rect', 'circle', 'dot',
     * 'diamond', 'triangle', 'trianglemid'
     */
    function DrawDot($x_world, $y_world, $record, $color)
    {
        // TODO: optimize, avoid counting every time we are called.
        $record = $record % count ($this->point_shapes);

        $half_point = $this->point_sizes[$record] / 2;

        $x_mid = $this->xtr($x_world);
        $y_mid = $this->ytr($y_world);

        $x1 = $x_mid - $half_point;
        $x2 = $x_mid + $half_point;
        $y1 = $y_mid - $half_point;
        $y2 = $y_mid + $half_point;

        switch ($this->point_shapes[$record]) {
        case 'halfline':
            ImageLine($this->img, $x1, $y_mid, $x_mid, $y_mid, $color);
            break;
        case 'line':
            ImageLine($this->img, $x1, $y_mid, $x2, $y_mid, $color);
            break;
        case 'plus':
            ImageLine($this->img, $x1, $y_mid, $x2, $y_mid, $color);
            ImageLine($this->img, $x_mid, $y1, $x_mid, $y2, $color);
            break;
        case 'cross':
            ImageLine($this->img, $x1, $y1, $x2, $y2, $color);
            ImageLine($this->img, $x1, $y2, $x2, $y1, $color);
            break;
        case 'rect':
            ImageFilledRectangle($this->img, $x1, $y1, $x2, $y2, $color);
            break;
        case 'circle':
            ImageArc($this->img, $x_mid, $y_mid, $this->point_sizes[$record], $this->point_sizes[$record], 0, 360, $color);
            break;
        case 'dot':
            ImageFilledArc($this->img, $x_mid, $y_mid, $this->point_sizes[$record], $this->point_sizes[$record], 0, 360,
                           $color, IMG_ARC_PIE);
            break;
        case 'diamond':
            $arrpoints = array( $x1, $y_mid, $x_mid, $y1, $x2, $y_mid, $x_mid, $y2);
            ImageFilledPolygon($this->img, $arrpoints, 4, $color);
            break;
        case 'triangle':
            $arrpoints = array( $x1, $y_mid, $x2, $y_mid, $x_mid, $y2);
            ImageFilledPolygon($this->img, $arrpoints, 3, $color);
            break;
        case 'trianglemid':
            $arrpoints = array( $x1, $y1, $x2, $y1, $x_mid, $y_mid);
            ImageFilledPolygon($this->img, $arrpoints, 3, $color);
            break;
        default:
            ImageFilledRectangle($this->img, $x1, $y1, $x2, $y2, $color);
            break;
        }
        return TRUE;
    }

    /*!
     * Draw an area plot. Supported data types:
     *      'text-data'
     *      'data-data'
     * NOTE: This function used to add first and last data values even on incomplete
     *       sets. That is not the behaviour now. As for missing data in between,
     *       there are two posibilities: replace the point with one on the X axis (previous
     *       way), or forget about it and use the preceding and following ones to draw the polygon.
     *       There is the possibility to use both, we just need to add the method to set
     *       it. Something like SetMissingDataBehaviour(), for example.
     */
    function DrawArea()
    {
        $incomplete_data_defaults_to_x_axis = FALSE;        // TODO: make this configurable

        for ($row = 0, $cnt = 0; $row < $this->num_data_rows; $row++) {
            $rec = 1;                                       // Skip record #0 (data label)

            if ($this->data_type == 'data-data')            // Do we have a value for X?
                $x_now = $this->data[$row][$rec++];         // Read it, advance record index
            else
                $x_now = 0.5 + $cnt++;                      // Place text-data at X = 0.5, 1.5, 2.5, etc...

            $x_now_pixels = $this->xtr($x_now);             // Absolute coordinates


            if ($this->x_data_label_pos != 'none')          // Draw X Data labels?
                $this->DrawXDataLabel($this->data[$row][0], $x_now_pixels);

            // Proceed with Y values
            // Create array of points for imagefilledpolygon()
            for($idx = 0; $rec < $this->num_recs[$row]; $rec++, $idx++) {
                if (is_numeric($this->data[$row][$rec])) {              // Allow for missing Y data 
                    $y_now_pixels = $this->ytr($this->data[$row][$rec]);

                    $posarr[$idx][] = $x_now_pixels;
                    $posarr[$idx][] = $y_now_pixels;

                    $num_points[$idx] = isset($num_points[$idx]) ? $num_points[$idx]+1 : 1;
                }
                // If there's missing data...
                else {
                    if (isset ($incomplete_data_defaults_to_x_axis)) {
                        $posarr[$idx][] = $x_now_pixels;
                        $posarr[$idx][] = $this->x_axis_y_pixels;
                        $num_points[$idx] = isset($num_points[$idx]) ? $num_points[$idx]+1 : 1;
                    }
                }
            }
        }   // end for

        $end = count($posarr);
        for ($i = 0; $i < $end; $i++) {
            // Prepend initial points. X = first point's X, Y = x_axis_y_pixels
            $x = $posarr[$i][0];
            array_unshift($posarr[$i], $x, $this->x_axis_y_pixels);

            // Append final points. X = last point's X, Y = x_axis_y_pixels
            $x = $posarr[$i][count($posarr[$i])-2];
            array_push($posarr[$i], $x, $this->x_axis_y_pixels);

            $num_points[$i] += 2;

            // Draw the poligon
            ImageFilledPolygon($this->img, $posarr[$i], $num_points[$i], $this->ndx_data_colors[$i]);
        }

    } // function DrawArea()


    /*!
     * Draw Lines. Supported data-types:
     *      'data-data', 
     *      'text-data'
     * NOTE: Please see the note regarding incomplete data sets on DrawArea()
     */
    function DrawLines() 
    {
        // This will tell us if lines have already begun to be drawn.
        // It is an array to keep separate information for every line, with a single
        // variable we would sometimes get "undefined offset" errors and no plot...
        $start_lines = array_fill(0, $this->records_per_group, FALSE);

        if ($this->data_type == 'text-data') { 
            $lastx[0] = $this->xtr(0);
            $lasty[0] = $this->xtr(0);
        }

        for ($row = 0, $cnt = 0; $row < $this->num_data_rows; $row++) {
            $record = 1;                                    // Skip record #0 (data label)

            if ($this->data_type == 'data-data')            // Do we have a value for X?
                $x_now = $this->data[$row][$record++];      // Read it, advance record index
            else
                $x_now = 0.5 + $cnt++;                      // Place text-data at X = 0.5, 1.5, 2.5, etc...

            $x_now_pixels = $this->xtr($x_now);             // Absolute coordinates

            if ($this->x_data_label_pos != 'none')          // Draw X Data labels?
                $this->DrawXDataLabel($this->data[$row][0], $x_now_pixels, $row);

            for ($idx = 0; $record < $this->num_recs[$row]; $record++, $idx++) {
                if (is_numeric($this->data[$row][$record])) {           //Allow for missing Y data 
                    $y_now_pixels = $this->ytr($this->data[$row][$record]);

                    if ($start_lines[$idx] == TRUE) {
                        // Set line width, revert it to normal at the end
                        ImageSetThickness($this->img, $this->line_widths[$idx]);

                        if ($this->line_styles[$idx] == 'dashed') {
                            $this->SetDashedStyle($this->ndx_data_colors[$idx]);
                            ImageLine($this->img, $x_now_pixels, $y_now_pixels, $lastx[$idx], $lasty[$idx], 
                                      IMG_COLOR_STYLED);
                        } else {
                            ImageLine($this->img, $x_now_pixels, $y_now_pixels, $lastx[$idx], $lasty[$idx], 
                                      $this->ndx_data_colors[$idx]);
                        }

                    }
                    $lasty[$idx] = $y_now_pixels;
                    $lastx[$idx] = $x_now_pixels;
                    $start_lines[$idx] = TRUE;
                } 
                // Y data missing... should we leave a blank or not?
                else if ($this->draw_broken_lines) {
                    $start_lines[$idx] = FALSE;
                }
            }   // end for
        }   // end for

        ImageSetThickness($this->img, 1);       // Revert to original state for lines to be drawn later. 
    } // function DrawLines()


    /*!
     * Draw lines with error bars - data comes in as 
     *      array("label", x, y, error+, error-, y2, error2+, error2-, ...);
     */
    function DrawLinesError() 
    {
        if ($this->data_type != 'data-data-error') {
            $this->DrawError("DrawLinesError(): Data type '$this->data_type' not supported.");
            return FALSE;
        }

        $start_lines = array_fill(0, $this->records_per_group, FALSE);

        for ($row = 0, $cnt = 0; $row < $this->num_data_rows; $row++) {
            $record = 1;                                    // Skip record #0 (data label)

            $x_now = $this->data[$row][$record++];          // Read X value, advance record index

            $x_now_pixels = $this->xtr($x_now);             // Absolute coordinates.
            

            if ($this->x_data_label_pos != 'none')          // Draw X Data labels?
                $this->DrawXDataLabel($this->data[$row][0], $x_now_pixels, $row);

            // Now go for Y, E+, E-
            for ($idx = 0; $record < $this->num_recs[$row]; $idx++) {
                // Y
                $y_now = $this->data[$row][$record++];
                $y_now_pixels = $this->ytr($y_now);

                if ($start_lines[$idx] == TRUE) {
                    ImageSetThickness($this->img, $this->line_widths[$idx]);

                    if ($this->line_styles[$idx] == 'dashed') {
                        $this->SetDashedStyle($this->ndx_data_colors[$idx]);
                        ImageLine($this->img, $x_now_pixels, $y_now_pixels, $lastx[$idx], $lasty[$idx], 
                                  IMG_COLOR_STYLED);
                    } else {
                        ImageLine($this->img, $x_now_pixels, $y_now_pixels, $lastx[$idx], $lasty[$idx], 
                                  $this->ndx_data_colors[$idx]);
                    }
                }

                // Error+
                $val = $this->data[$row][$record++];
                $this->DrawYErrorBar($x_now, $y_now, $val, $this->error_bar_shape, 
                                     $this->ndx_error_bar_colors[$idx]);

                // Error-
                $val = $this->data[$row][$record++];
                $this->DrawYErrorBar($x_now, $y_now, -$val, $this->error_bar_shape, 
                                     $this->ndx_error_bar_colors[$idx]);

                // Update indexes:
                $start_lines[$idx] = TRUE;   // Tells us if we already drew the first column of points, 
                                             // thus having $lastx and $lasty ready for the next column.
                $lastx[$idx] = $x_now_pixels;
                $lasty[$idx] = $y_now_pixels;
            }   // end while
        }   // end for

        ImageSetThickness($this->img, 1);   // Revert to original state for lines to be drawn later.
    }   // function DrawLinesError()



    /*!
     * This is a mere copy of DrawLines() with one more line drawn for each point
     */
    function DrawSquared() 
    {
        // This will tell us if lines have already begun to be drawn.
        // It is an array to keep separate information for every line, for with a single
        // variable we could sometimes get "undefined offset" errors and no plot...
        $start_lines = array_fill(0, $this->records_per_group, FALSE);

        if ($this->data_type == 'text-data') { 
            $lastx[0] = $this->xtr(0);
            $lasty[0] = $this->xtr(0);
        }
        
        for ($row = 0, $cnt = 0; $row < $this->num_data_rows; $row++) {
            $record = 1;                                    // Skip record #0 (data label)

            if ($this->data_type == 'data-data')            // Do we have a value for X?
                $x_now = $this->data[$row][$record++];      // Read it, advance record index
            else
                $x_now = 0.5 + $cnt++;                      // Place text-data at X = 0.5, 1.5, 2.5, etc...

            $x_now_pixels = $this->xtr($x_now);             // Absolute coordinates

            if ($this->x_data_label_pos != 'none')          // Draw X Data labels?
                $this->DrawXDataLabel($this->data[$row][0], $x_now_pixels); // notice there is no last param.
                
            // Draw Lines
            for ($idx = 0; $record < $this->num_recs[$row]; $record++, $idx++) {
                if (is_numeric($this->data[$row][$record])) {               // Allow for missing Y data 
                    $y_now_pixels = $this->ytr($this->data[$row][$record]);

                    if ($start_lines[$idx] == TRUE) {
                        // Set line width, revert it to normal at the end
                        ImageSetThickness($this->img, $this->line_widths[$idx]);

                        if ($this->line_styles[$idx] == 'dashed') {
                            $this->SetDashedStyle($this->ndx_data_colors[$idx]);
                            ImageLine($this->img, $lastx[$idx], $lasty[$idx], $x_now_pixels, $lasty[$idx],
                                      IMG_COLOR_STYLED);
                            ImageLine($this->img, $x_now_pixels, $lasty[$idx], $x_now_pixels, $y_now_pixels, 
                                      IMG_COLOR_STYLED);
                        } else {
                            ImageLine($this->img, $lastx[$idx], $lasty[$idx], $x_now_pixels, $lasty[$idx],
                                      $this->ndx_data_colors[$idx]);
                            ImageLine($this->img, $x_now_pixels, $lasty[$idx], $x_now_pixels, $y_now_pixels,
                                      $this->ndx_data_colors[$idx]);
                        }
                    }
                    $lastx[$idx] = $x_now_pixels;
                    $lasty[$idx] = $y_now_pixels;
                    $start_lines[$idx] = TRUE;
                } 
                // Y data missing... should we leave a blank or not?
                else if ($this->draw_broken_lines) {
                    $start_lines[$idx] = FALSE;
                } 
            }
        }   // end while

        ImageSetThickness($this->img, 1); 
    } // function DrawSquared()


    /*!    
     * Data comes in as array("title", x, y, y2, y3, ...)
     */
    function DrawBars()
    {
        if ($this->data_type != 'text-data') {
            $this->DrawError('DrawBars(): Bar plots must be text-data: use function SetDataType("text-data")');
            return FALSE;
        }

        for ($row = 0; $row < $this->num_data_rows; $row++) {
            $record = 1;                                    // Skip record #0 (data label)

            $x_now_pixels = $this->xtr(0.5 + $row);         // Place text-data at X = 0.5, 1.5, 2.5, etc...

            if ($this->x_data_label_pos != 'none')          // Draw X Data labels? TODO:labels on top of bars.
                $this->DrawXDataLabel($this->data[$row][0], $x_now_pixels);

            // Draw the bar
            for ($idx = 0; $record < $this->num_recs[$row]; $record++, $idx++) {
                if (is_numeric($this->data[$row][$record])) {       // Allow for missing Y data
                    $x1 = $x_now_pixels - $this->data_group_space + ($idx * $this->record_bar_width);
                    $x2 = $x1 + ($this->bar_width_adjust * $this->record_bar_width);

                    if ($this->data[$row][$record] < $this->x_axis_position) {
                        $y1 = $this->x_axis_y_pixels;
                        $y2 = $this->ytr($this->data[$row][$record]);
                    } else {
                        $y1 = $this->ytr($this->data[$row][$record]);
                        $y2 = $this->x_axis_y_pixels;
                    }

                    if ($this->shading) {                           // Draw the shade?
                        ImageFilledPolygon($this->img, array($x1, $y1,
                                                       $x1 + $this->shading, $y1 - $this->shading,
                                                       $x2 + $this->shading, $y1 - $this->shading,
                                                       $x2 + $this->shading, $y2 - $this->shading,
                                                       $x2, $y2,
                                                       $x2, $y1),
                                           6, $this->ndx_data_dark_colors[$idx]);
                    }
                    // Or draw a border?
                    else {
                        ImageRectangle($this->img, $x1, $y1, $x2,$y2, $this->ndx_data_border_colors[$idx]);
                    }
                    // Draw the bar
                    ImageFilledRectangle($this->img, $x1, $y1, $x2, $y2, $this->ndx_data_colors[$idx]);
                }
            }   // end for
        }   // end for
    } //function DrawBars


    /*!
     * Data comes in as array("title", x, y, y2, y3, ...)
     * \note Original stacked bars idea by Laurent Kruk < lolok at users.sourceforge.net >
     */
    function DrawStackedBars()
    {
        if ($this->data_type != 'text-data') {
            $this->DrawError('DrawStackedBars(): Bar plots must be text-data: use SetDataType("text-data")');
            return FALSE;
        }

        for ($row = 0; $row < $this->num_data_rows; $row++) {
            $record = 1;                                    // Skip record #0 (data label)

            $x_now_pixels = $this->xtr(0.5 + $row);         // Place text-data at X = 0.5, 1.5, 2.5, etc...

            if ($this->x_data_label_pos != 'none')          // Draw X Data labels?
                $this->DrawXDataLabel($this->data[$row][0], $x_now_pixels);

            // Draw the bars
            $oldv = 0;
            for ($idx = 0; $record < $this->num_recs[$row]; $record++, $idx++) {
                if (is_numeric($this->data[$row][$record])) {       // Allow for missing Y data 
                    $x1 = $x_now_pixels - $this->data_group_space;
                    $x2 = $x_now_pixels + $this->data_group_space; 

                    $y1 = $this->ytr(abs($this->data[$row][$record]) + $oldv);
                    $y2 = $this->ytr($this->x_axis_position + $oldv);
                    $oldv += abs($this->data[$row][$record]);

                    if ($this->shading) {                           // Draw the shade?
                        ImageFilledPolygon($this->img, array($x1, $y1, 
                                                       $x1 + $this->shading, $y1 - $this->shading,
                                                       $x2 + $this->shading, $y1 - $this->shading,
                                                       $x2 + $this->shading, $y2 - $this->shading,
                                                       $x2, $y2,
                                                       $x2, $y1),
                                           6, $this->ndx_data_dark_colors[$idx]);
                    } 
                    // Or draw a border?
                    else {
                        ImageRectangle($this->img, $x1, $y1, $x2,$y2, $this->ndx_data_border_colors[$idx]);
                    }
                    // Draw the bar
                    ImageFilledRectangle($this->img, $x1, $y1, $x2, $y2, $this->ndx_data_colors[$idx]);
                    
                } 
            }   // end for
        }   // end for
    } //function DrawStackedBars 

    
    /*!
     *
     */
    function DrawGraph()
    {
        if (! $this->img) {
            $this->DrawError('DrawGraph(): No image resource allocated');
            return FALSE;
        }

        if (isset($this->data) && !is_array($this->data)) {
            $this->DrawError("DrawGraph(): No array of data in \$data");
            return FALSE;
        }

        if (! isset($this->data_limits_done))
            $this->FindDataLimits();                // Get maxima and minima for scaling

        if ($this->total_records == 0) {            // Check for empty data sets
            $this->DrawError('Empty data set');
            return FALSE;
        }

        $this->CalcMargins();                       // Calculate margins

        if (! isset($this->plot_area_width))        // Set plot area pixel values (plot_area[])
            $this->SetPlotAreaPixels();

        if (! isset($this->plot_max_y))             // Set plot area world values (plot_max_x, etc.)
            $this->SetPlotAreaWorld();

        if ($this->plot_type == 'bars' || $this->plot_type == 'stackedbars') // Calculate bar widths
            $this->CalcBarWidths();
/* FIXME!!  this sort of thing should not be done without user's consent
        if ($this->x_data_label_pos != 'none') {    // Default: do not draw tick stuff if
            $this->x_tick_label_pos = 'none';       // there are data labels.
            $this->x_tick_pos = 'none';
        }
*/
        $this->PadArrays();                         // Pad color and style arrays to fit records per group.

        $this->DrawBackground();

        $this->DrawImageBorder();

        $this->DrawPlotAreaBackground();

        $this->DrawTitle();
        $this->DrawXTitle();
        $this->DrawYTitle();

        // Pie charts are drawn differently, handle them first
        if ($this->plot_type == 'pie') {
            // Pie charts can maximize image space usage.
            $this->SetPlotAreaPixels($this->safe_margin, $this->title_height,
                                     $this->image_width - $this->safe_margin,
                                     $this->image_height - $this->safe_margin);
            $this->DrawPieChart();

            if ($this->legend)
                $this->DrawLegend($this->legend_x_pos, $this->legend_y_pos, '');

            if ($this->print_image)
                $this->PrintImage();
                
            return;
        }

        ////// All other chart types:
        
        if (! $this->grid_at_foreground) {         // Usually one wants grids to go back, but...
            $this->DrawYAxis();     // Y axis must be drawn before X axis (see DrawYAxis()) 
            $this->DrawXAxis();
        }

        switch ($this->plot_type) {
        case 'thinbarline':
            $this->DrawThinBarLines();
            break;
        case 'area':
            $this->DrawArea();
            break;
        case 'squared':
            $this->DrawSquared();
            break;
        case 'lines':
            if ( $this->data_type == 'data-data-error') {
                $this->DrawLinesError();
            } else {
                $this->DrawLines();
            }
            break;
        case 'linepoints':          // FIXME !!! DrawXDataLabel gets called in DrawLines() and DrawDots()
            if ( $this->data_type == 'data-data-error') {
                $this->DrawLinesError();
                $this->DrawDotsError();
            } else {
                $this->DrawLines();
                $this->DrawDots();
            }
            break;
        case 'points';
            if ( $this->data_type == 'data-data-error') {
                $this->DrawDotsError();
            } else {
                $this->DrawDots();
            }
            break;
        case 'stackedbars':
            $this->DrawStackedBars();
            break; 
        case 'bars':
            $this->DrawBars();
            break;
        default:
            $this->plot_type = 'bars';  // Set it if it wasn't already set.
            $this->DrawBars();
            break;
        }   // end switch

        if ($this->grid_at_foreground) {         // Usually one wants grids to go back, but...
            $this->DrawYAxis();     // Y axis must be drawn before X axis (see DrawYAxis()) 
            $this->DrawXAxis();
        }

        $this->DrawPlotBorder();
        
        if ($this->legend)
            $this->DrawLegend($this->legend_x_pos, $this->legend_y_pos, '');

        if ($this->print_image)
            $this->PrintImage();

    } //function DrawGraph()

/////////////////////////////////////////////
//////////////////         DEPRECATED METHODS
/////////////////////////////////////////////

    /*!
     * Deprecated, use SetYTickPos()
     */
    function SetDrawVertTicks($which_dvt) 
    {
        if ($which_dvt != 1)
            $this->SetYTickPos('none');
        return TRUE;
    } 

    /*!
     * Deprecated, use SetXTickPos()
     */
    function SetDrawHorizTicks($which_dht) 
    {
        if ($which_dht != 1)
           $this->SetXTickPos('none');
        return TRUE;
    }

    /*!
     * \deprecated Use SetNumXTicks()
     */
    function SetNumHorizTicks($n) 
    {
        return $this->SetNumXTicks($n);
    }

    /*!
     * \deprecated Use SetNumYTicks()
     */
    function SetNumVertTicks($n) 
    {
        return $this->SetNumYTicks($n);
    }

    /*!
     * \deprecated Use SetXTickIncrement()
     */
    function SetHorizTickIncrement($inc) 
    {
        return $this->SetXTickIncrement($inc);
    }


    /*!
     * \deprecated Use SetYTickIncrement()
     */
    function SetVertTickIncrement($inc) 
    {
        return $this->SetYTickIncrement($inc);
    }

    /*!
     * \deprecated Use SetYTickPos()
     */
    function SetVertTickPosition($which_tp) 
    { 
        return $this->SetYTickPos($which_tp); 
    }

    /*!
     * \deprecated Use SetXTickPos()
     */
    function SetHorizTickPosition($which_tp) 
    { 
        return $this->SetXTickPos($which_tp);
    }

    /*!
     * \deprecated Use SetFont()
     */
    function SetTitleFontSize($which_size) 
    {
        return $this->SetFont('title', $which_size);
    }

    /*!
     * \deprecated Use SetFont()
     */
    function SetAxisFontSize($which_size) 
    {
        $this->SetFont('x_label', $which_size);
        $this->SetFont('y_label', $whic_size);
    }

    /*!
     * \deprecated Use SetFont()
     */
    function SetSmallFontSize($which_size) 
    {
        return $this->SetFont('generic', $which_size);
    }

    /*!
     * \deprecated Use SetFont()
     */
    function SetXLabelFontSize($which_size)
    {
        return $this->SetFont('x_title', $which_size);
    }

    /*!
     * \deprecated Use SetFont()
     */
    function SetYLabelFontSize($which_size) 
    {
        return $this->SetFont('y_title', $which_size);
    }

    /*!
     * \deprecated Use SetXTitle()
     */
    function SetXLabel($which_xlab) 
    {
        return $this->SetXTitle($which_xlab);
    }

    /*!
     * \deprecated Use SetYTitle()
     */ 
    function SetYLabel($which_ylab) 
    {
        return $this->SetYTitle($which_ylab);
    }   

    /*!
     * \deprecated This is now an Internal function - please set width and 
     *             height via PHPlot() upon object construction
     */
    function SetImageArea($which_iw, $which_ih) 
    {
        $this->image_width = $which_iw;
        $this->image_height = $which_ih;

        return TRUE;
    }

    /*!
     * \deprecated Use SetXTickLength() and SetYTickLength() instead.
     */
    function SetTickLength($which_tl) 
    {
        $this->SetXTickLength($which_tl);
        $this->SetYTickLength($which_tl);
        return TRUE;
    }

    /*!
     * \deprecated  Use SetYLabelType()
     */
    function SetYGridLabelType($which_yglt) 
    {
        return $this->SetYLabelType($which_yglt);
    }

    /*!
     * \deprecated  Use SetXLabelType()
     */
    function SetXGridLabelType($which_xglt) 
    {
        return $this->SetXLabelType($which_xglt);
    }
    /*!
     * \deprecated Use SetYTickLabelPos()
     */
    function SetYGridLabelPos($which_yglp) 
    {
        return $this->SetYTickLabelPos($which_yglp);
    }
    /*!
     * \deprecated Use SetXTickLabelPos()
     */
    function SetXGridLabelPos($which_xglp) 
    {
        return $this->SetXTickLabelPos($which_xglp);
    }


    /*!
     * \deprecated Use SetXtitle()
     */
    function SetXTitlePos($xpos) 
    {
        $this->x_title_pos = $xpos;
        return TRUE;
    }

    /*!
     * \deprecated Use SetYTitle()
     */
    function SetYTitlePos($xpos) 
    {
        $this->y_title_pos = $xpos;
        return TRUE;
    }

    /*!
     * \deprecated  Use DrawDots()
     */
    function DrawDotSeries() 
    {
        $this->DrawDots();
    }

    /*!
     * \deprecated Use SetXLabelAngle()
     */
    function SetXDataLabelAngle($which_xdla)
    {
        return $this->SetXLabelAngle($which_xdla);
    }

    /*!
     * Draw Labels (not grid labels) on X Axis, following data points. Default position is 
     * down of plot. Care must be taken not to draw these and x_tick_labels as they'd probably overlap.
     *
     * \deprecated Use SetXDataLabelPos()
     */
    function SetDrawXDataLabels($which_dxdl)
    {
        if ($which_dxdl == '1' )
            $this->SetXDataLabelPos('plotdown');
        else
            $this->SetXDataLabelPos('none');
    }

    /*!
     * \deprecated This method was intended to improve performance by being specially 
     * written for 'data-data'. However, the improvement didn't pay. Use DrawLines() instead
     */
    function DrawLineSeries() 
    {
        return $this->DrawLines();
    }

    /*!
     * \deprecated Calculates maximum X-Axis label height. Now inside CalcMargins()
     */
    function CalcXHeights() 
    {
        // TTF
        if ($this->use_ttf) {
            $xstr = str_repeat('.', $this->max_t);
            $size = $this->TTFBBoxSize($this->x_label_font['size'], $this->x_label_angle,
                                       $this->x_label_font['font'], $xstr);
            $this->x_tick_label_height = $size[1];
        } 
        // Fixed font
        else { // For Non-TTF fonts we can have only angles 0 or 90
            if ($this->x_label_angle == 90)
                $this->x_tick_label_height = $this->max_t * $this->x_label_font['width'];
            else
                $this->x_tick_label_height = $this->x_label_font['height'];
        }

        return TRUE;
    }


    /*!
     * \deprecated Calculates Maximum Y-Axis tick label width. Now inside CalcMargins()
     */
    function CalcYWidths() 
    {
        //the "." is for space. It isn't actually printed
        $ylab = number_format($this->max_y, $this->y_precision, '.', ', ') . $this->data_units_text . '.';

        // TTF
        if ($this->use_ttf) {
            // Maximum Y tick label width
            $size = $this->TTFBBoxSize($this->y_label_font['size'], 0, $this->y_label_font['font'], $ylab);
            $this->y_tick_label_width = $size[0];

        } 
        // Fixed font
        else {
            // Y axis title width
            $this->y_tick_label_width = strlen($ylab) * $this->y_label_font['width'];
        }

        return TRUE;
    }

    /*!
     * \deprecated Superfluous.
     */
    function DrawLabels() 
    {
        $this->DrawTitle();
        $this->DrawXTitle();
        $this->DrawYTitle();
    }

    /*! 
     * Set up the image resource 'img'
     * \deprecated The constructor should init 'img'
     */
    function InitImage()
    {
        $this->img = ImageCreate($this->image_width, $this->image_height);

        if (! $this->img)
            $this->PrintError('InitImage(): Could not create image resource');
        return TRUE;
    }

    /*!
     * \deprecated
     */
    function SetNewPlotAreaPixels($x1, $y1, $x2, $y2) 
    {
        //Like in GD 0, 0 is upper left set via pixel Coordinates
        $this->plot_area = array($x1, $y1, $x2, $y2);
        $this->plot_area_width = $this->plot_area[2] - $this->plot_area[0];
        $this->plot_area_height = $this->plot_area[3] - $this->plot_area[1];
        $this->y_top_margin = $this->plot_area[1];

        if (isset($this->plot_max_x))
            $this->CalcTranslation();

        return TRUE;
    }

    /*!
     * \deprecated Use _SetRGBColor()
     */
    function SetColor($which_color)
    {
        $this->SetRGBColor($which_color);
        return TRUE;
    }

    /*
     * \deprecated Use SetLineWidths().
     */
    function SetLineWidth($which_lw)
    {

        $this->SetLineWidths($which_lw);

        if (!$this->error_bar_line_width) {
            $this->SetErrorBarLineWidth($which_lw);
        }
        return TRUE;
    }

    /*!
     * \deprecated
     */
    function DrawDashedLine($x1, $y1, $x2, $y2 , $dash_length, $dash_space, $color)
    {
        if ($dash_length)
            $dashes = array_fill(0, $dash_length, $color);
        else
            $dashes = array();
        if ($dash_space)
            $spaces = array_fill(0, $dash_space, IMG_COLOR_TRANSPARENT);
        else
            $spaces = array();

        $style = array_merge($dashes, $spaces);
        ImageSetStyle($this->img, $style);
        ImageLine($this->img, $x1, $y1, $x2, $y2, IMG_COLOR_STYLED);
    }

    /*!
     * \deprecated Selects an input file to be used as background for the whole graph.
     * This resizes the graph to the image's size.
     */
    function SetInputFile($which_input_file)
    {
        $size = GetImageSize($which_input_file);
        $input_type = $size[2];

        switch($input_type) {
        case 1:
            $im = @ ImageCreateFromGIF ($which_input_file);
            if (!$im) { // See if it failed
                $this->PrintError("Unable to open $which_input_file as a GIF");
                return FALSE;
            }
        break;
        case 3:
            $im = @ ImageCreateFromPNG ($which_input_file);
            if (!$im) { // See if it failed
                $this->PrintError("Unable to open $which_input_file as a PNG");
                return FALSE;
            }
        break;
        case 2:
            $im = @ ImageCreateFromJPEG ($which_input_file);
            if (!$im) { // See if it failed
                $this->PrintError("Unable to open $which_input_file as a JPG");
                return FALSE;
            }
        break;
        default:
            $this->PrintError('SetInputFile(): Please select gif, jpg, or png for image type!');
            return FALSE;
        break;
        }

        // Set Width and Height of Image
        $this->image_width = $size[0];
        $this->image_height = $size[1];

        // Deallocate any resources previously allocated
        if ($this->img)
            imagedestroy($this->img);

        $this->img = $im;

        return TRUE;

    }


    /*
     * \deprecated Use SetPointShapes().
     */
    function SetPointShape($which_pt)
    {
        $this->SetPointShapes($which_pt);
        return TRUE;
    }

    /*
     * \deprecated Use SetPointSizes().
     */
    function SetPointSize($which_ps)
    {
        $this->SetPointSizes($which_ps);
        return TRUE;
    }
}  // class PHPlot



////////////////////////


/*!
 * Pads an array with another or with itself.
 *  \param arr array  Original array (reference)
 *  \param size int   Size of the resulting array.
 *  \param arr2 array If specified, array to use for padding. If unspecified, pad with $arr.
 */
function array_pad_array(&$arr, $size, $arr2=NULL)
{
    if (! is_array($arr2)) {
        $arr2 = $arr;                           // copy the original array
    }
    while (count($arr) < $size)
        $arr = array_merge_php4($arr, $arr2);        // append until done
}

/*!
 * Fixes problem with array_merge() in PHP5.
 * \note I simply copied this from a bug report. I am not running php5 yet, so
 *       I cannot reproduce it, which is why I trust the reporter.
 */
function array_merge_php4($array1,$array2)
{
    $return=array();

    foreach(func_get_args() as $arg){
        if(!is_array($arg)){
        $arg=array($arg);
        }
        foreach($arg as $key=>$val){
            if(!is_int($key)){
                $return[$key]=$val;
            }else{
                $return[]=$val;
            }
        }
    }
    return $return;
 }
 
 


?>
