<?php
  /*=======================================================================
   // File:        JPGRAPH_RADAR.PHP
   // Description: Radar plot extension for JpGraph
   // Created:     2001-02-04
   // Ver:         $Id: jpgraph_radar.php 1783 2009-08-25 11:41:01Z ljp $
   //
   // Copyright (c) Asial Corporation. All rights reserved.
   //========================================================================
   */
  
  require_once('jpgraph_plotmark.inc.php');
  
  //===================================================
  // CLASS RadarLogTicks
  // Description: Logarithmic ticks
  //===================================================
  class RadarLogTicks extends Ticks {
  
      function __construct() {
              // Empty
      }
  
      function Stroke($aImg,&$grid,$aPos,$aAxisAngle,$aScale,&$aMajPos,&$aMajLabel) {
          $start = $aScale->GetMinVal();
          $limit = $aScale->GetMaxVal();
          $nextMajor = 10*$start;
          $step = $nextMajor / 10.0;
          $count=1;
  
          $ticklen_maj=5;
          $dx_maj=round(sin($aAxisAngle)*$ticklen_maj);
          $dy_maj=round(cos($aAxisAngle)*$ticklen_maj);
          $ticklen_min=3;
          $dx_min=round(sin($aAxisAngle)*$ticklen_min);
          $dy_min=round(cos($aAxisAngle)*$ticklen_min);
  
          $aMajPos=array();
          $aMajLabel=array();
  
          if( $this->supress_first ) {
              $aMajLabel[] = '';
          }
          else {
              $aMajLabel[]=$start;
          }
  
          $yr=$aScale->RelTranslate($start);
          $xt=round($yr*cos($aAxisAngle))+$aScale->scale_abs[0];
          $yt=$aPos-round($yr*sin($aAxisAngle));
          $aMajPos[]=$xt+2*$dx_maj;
          $aMajPos[]=$yt-$aImg->GetFontheight()/2;
          $grid[]=$xt;
          $grid[]=$yt;
  
          $aImg->SetLineWeight($this->weight);
  
          for($y=$start; $y<=$limit; $y+=$step,++$count  ) {
              $yr=$aScale->RelTranslate($y);
              $xt=round($yr*cos($aAxisAngle))+$aScale->scale_abs[0];
              $yt=$aPos-round($yr*sin($aAxisAngle));
              if( $count % 10 == 0 ) {
                  $grid[]=$xt;
                  $grid[]=$yt;
                  $aMajPos[]=$xt+2*$dx_maj;
                  $aMajPos[]=$yt-$aImg->GetFontheight()/2;
                  if( !$this->supress_tickmarks ) {
                      if( $this->majcolor != '' ) {
                          $aImg->PushColor($this->majcolor);
                      }
                      $aImg->Line($xt+$dx_maj,$yt+$dy_maj,$xt-$dx_maj,$yt-$dy_maj);
                      if( $this->majcolor != '' ) {
                          $aImg->PopColor();
                      }
                  }
                  if( $this->label_formfunc != '' ) {
                      $f=$this->label_formfunc;
                      $l = call_user_func($f,$nextMajor);
                  }
                  else {
                      $l = $nextMajor;
                  }
  
                  $aMajLabel[]=$l;
                  $nextMajor *= 10;
                  $step *= 10;
                  $count=1;
              }
              else {
                  if( !$this->supress_minor_tickmarks ) {
                      if( $this->mincolor != '' ) {
                          $aImg->PushColor($this->mincolor);
                      }
                      $aImg->Line($xt+$dx_min,$yt+$dy_min,$xt-$dx_min,$yt-$dy_min);
                      if( $this->mincolor != '' ) {
                          $aImg->PopColor();
                      }
                  }
              }
          }
      }
  }
  
  //===================================================
  // CLASS RadarLinear
  // Description: Linear ticks
  //===================================================
  class RadarLinearTicks extends Ticks {
  
      private $minor_step=1, $major_step=2;
      private $xlabel_offset=0,$xtick_offset=0;
  
      function __construct() {
          // Empty
      }
  
      // Return major step size in world coordinates
      function GetMajor() {
          return $this->major_step;
      }
  
      // Return minor step size in world coordinates
      function GetMinor() {
          return $this->minor_step;
      }
  
      // Set Minor and Major ticks (in world coordinates)
      function Set($aMajStep,$aMinStep=false) {
          if( $aMinStep==false ) {
              $aMinStep=$aMajStep;
          }
  
          if( $aMajStep <= 0 || $aMinStep <= 0 ) {
              JpGraphError::RaiseL(25064);
              //JpGraphError::Raise(" Minor or major step size is 0. Check that you haven't got an accidental SetTextTicks(0) in your code. If this is not the case you might have stumbled upon a bug in JpGraph. Please report this and if possible include the data that caused the problem.");
          }
  
          $this->major_step=$aMajStep;
          $this->minor_step=$aMinStep;
          $this->is_set = true;
      }
  
      function Stroke($aImg,&$grid,$aPos,$aAxisAngle,$aScale,&$aMajPos,&$aMajLabel) {
          // Prepare to draw linear ticks
          $maj_step_abs = abs($aScale->scale_factor*$this->major_step);
          $min_step_abs = abs($aScale->scale_factor*$this->minor_step);
          $nbrmaj = round($aScale->world_abs_size/$maj_step_abs);
          $nbrmin = round($aScale->world_abs_size/$min_step_abs);
          $skip = round($nbrmin/$nbrmaj); // Don't draw minor on top of major
  
          // Draw major ticks
          $ticklen2=$this->major_abs_size;
          $dx=round(sin($aAxisAngle)*$ticklen2);
          $dy=round(cos($aAxisAngle)*$ticklen2);
          $label=$aScale->scale[0]+$this->major_step;
  
          $aImg->SetLineWeight($this->weight);
  
          $aMajPos = array();
          $aMajLabel = array();
  
          for($i=1; $i<=$nbrmaj; ++$i) {
              $xt=round($i*$maj_step_abs*cos($aAxisAngle))+$aScale->scale_abs[0];
              $yt=$aPos-round($i*$maj_step_abs*sin($aAxisAngle));
  
              if( $this->label_formfunc != '' ) {
                  $f=$this->label_formfunc;
                  $l = call_user_func($f,$label);
              }
              else {
                  $l = $label;
              }
  
              $aMajLabel[]=$l;
              $label += $this->major_step;
              $grid[]=$xt;
              $grid[]=$yt;
              $aMajPos[($i-1)*2]=$xt+2*$dx;
              $aMajPos[($i-1)*2+1]=$yt-$aImg->GetFontheight()/2;
              if( !$this->supress_tickmarks ) {
                  if( $this->majcolor != '' ) {
                      $aImg->PushColor($this->majcolor);
                  }
                  $aImg->Line($xt+$dx,$yt+$dy,$xt-$dx,$yt-$dy);
                  if( $this->majcolor != '' ) {
                      $aImg->PopColor();
                  }
              }
          }
  
          // Draw minor ticks
          $ticklen2=$this->minor_abs_size;
          $dx=round(sin($aAxisAngle)*$ticklen2);
          $dy=round(cos($aAxisAngle)*$ticklen2);
          if( !$this->supress_tickmarks && !$this->supress_minor_tickmarks) {
              if( $this->mincolor != '' ) {
                  $aImg->PushColor($this->mincolor);
              }
              for($i=1; $i<=$nbrmin; ++$i) {
                  if( ($i % $skip) == 0 ) {
                      continue;
                  }
                  $xt=round($i*$min_step_abs*cos($aAxisAngle))+$aScale->scale_abs[0];
                  $yt=$aPos-round($i*$min_step_abs*sin($aAxisAngle));
                  $aImg->Line($xt+$dx,$yt+$dy,$xt-$dx,$yt-$dy);
              }
              if( $this->mincolor != '' ) {
                  $aImg->PopColor();
              }
          }
      }
  }
  
  
  //===================================================
  // CLASS RadarAxis
  // Description: Implements axis for the radar graph
  //===================================================
  class RadarAxis extends AxisPrototype {
      public $title=null;
      private $title_color='navy';
      private $len=0;
  
      function __construct($img,$aScale,$color=array(0,0,0)) {
          parent::__construct($img,$aScale,$color);
          $this->len = $img->plotheight;
          $this->title = new Text();
          $this->title->SetFont(FF_FONT1,FS_BOLD);
          $this->color = array(0,0,0);
      }
  
      // Stroke the axis
      // $pos    = Vertical position of axis
      // $aAxisAngle = Axis angle
      // $grid   = Returns an array with positions used to draw the grid
      // $lf   = Label flag, TRUE if the axis should have labels
      function Stroke($pos,$aAxisAngle,&$grid,$title,$lf) {
          $this->img->SetColor($this->color);
  
          // Determine end points for the axis
          $x=round($this->scale->world_abs_size*cos($aAxisAngle)+$this->scale->scale_abs[0]);
          $y=round($pos-$this->scale->world_abs_size*sin($aAxisAngle));
  
          // Draw axis
          $this->img->SetColor($this->color);
          $this->img->SetLineWeight($this->weight);
          if( !$this->hide ) {
              $this->img->Line($this->scale->scale_abs[0],$pos,$x,$y);
          }
  
          $this->scale->ticks->Stroke($this->img,$grid,$pos,$aAxisAngle,$this->scale,$majpos,$majlabel);
          $ncolor=0;
          if( isset($this->ticks_label_colors) ) {
              $ncolor=count($this->ticks_label_colors);
          }
  
          // Draw labels
          if( $lf && !$this->hide ) {
              $this->img->SetFont($this->font_family,$this->font_style,$this->font_size);
              $this->img->SetTextAlign('left','top');
              $this->img->SetColor($this->label_color);
  
              // majpos contains (x,y) coordinates for labels
              if( ! $this->hide_labels ) {
                  $n = floor(count($majpos)/2);
                  for($i=0; $i < $n; ++$i) {
                      // Set specific label color if specified
                      if( $ncolor > 0 ) {
                          $this->img->SetColor($this->ticks_label_colors[$i % $ncolor]);
                      }
  
                      if( $this->ticks_label != null && isset($this->ticks_label[$i]) ) {
                          $this->img->StrokeText($majpos[$i*2],$majpos[$i*2+1],$this->ticks_label[$i]);
                      }
                      else {
                          $this->img->StrokeText($majpos[$i*2],$majpos[$i*2+1],$majlabel[$i]);
                      }
                  }
              }
          }
          $this->_StrokeAxisTitle($pos,$aAxisAngle,$title);
      }
  
      function _StrokeAxisTitle($pos,$aAxisAngle,$title) {
          $this->title->Set($title);
          $marg=6+$this->title->margin;
          $xt=round(($this->scale->world_abs_size+$marg)*cos($aAxisAngle)+$this->scale->scale_abs[0]);
          $yt=round($pos-($this->scale->world_abs_size+$marg)*sin($aAxisAngle));
  
          // Position the axis title.
          // dx, dy is the offset from the top left corner of the bounding box that sorrounds the text
          // that intersects with the extension of the corresponding axis. The code looks a little
          // bit messy but this is really the only way of having a reasonable position of the
          // axis titles.
          if( $this->title->iWordwrap > 0 ) {
              $title = wordwrap($title,$this->title->iWordwrap,"\n");
          }
  
          $h=$this->img->GetTextHeight($title)*1.2;
          $w=$this->img->GetTextWidth($title)*1.2;
  
          while( $aAxisAngle > 2*M_PI )
              $aAxisAngle -= 2*M_PI;
  
          // Around 3 a'clock
          if( $aAxisAngle>=7*M_PI/4 || $aAxisAngle <= M_PI/4 ) $dx=-0.15; // Small trimming to make the dist to the axis more even
  
          // Around 12 a'clock
          if( $aAxisAngle>=M_PI/4 && $aAxisAngle <= 3*M_PI/4 ) $dx=($aAxisAngle-M_PI/4)*2/M_PI;
  
          // Around 9 a'clock
          if( $aAxisAngle>=3*M_PI/4 && $aAxisAngle <= 5*M_PI/4 ) $dx=1;
  
          // Around 6 a'clock
          if( $aAxisAngle>=5*M_PI/4 && $aAxisAngle <= 7*M_PI/4 ) $dx=(1-($aAxisAngle-M_PI*5/4)*2/M_PI);
  
          if( $aAxisAngle>=7*M_PI/4 ) $dy=(($aAxisAngle-M_PI)-3*M_PI/4)*2/M_PI;
          if( $aAxisAngle<=M_PI/12 ) $dy=(0.5-$aAxisAngle*2/M_PI);
          if( $aAxisAngle<=M_PI/4 && $aAxisAngle > M_PI/12) $dy=(1-$aAxisAngle*2/M_PI);
          if( $aAxisAngle>=M_PI/4 && $aAxisAngle <= 3*M_PI/4 ) $dy=1;
          if( $aAxisAngle>=3*M_PI/4 && $aAxisAngle <= 5*M_PI/4 ) $dy=(1-($aAxisAngle-3*M_PI/4)*2/M_PI);
          if( $aAxisAngle>=5*M_PI/4 && $aAxisAngle <= 7*M_PI/4 ) $dy=0;
  
          if( !$this->hide ) {
              $this->title->Stroke($this->img,$xt-$dx*$w,$yt-$dy*$h,$title);
          }
      }
  
  } // Class
  
  
  //===================================================
  // CLASS RadarGrid
  // Description: Draws grid for the radar graph
  //===================================================
  class RadarGrid { //extends Grid {
      private $type='solid';
      private $grid_color='#DDDDDD';
      private $show=false, $weight=1;
  
      function __construct() {
          // Empty
      }
  
      function SetColor($aMajColor) {
          $this->grid_color = $aMajColor;
      }
  
      function SetWeight($aWeight) {
          $this->weight=$aWeight;
      }
  
      // Specify if grid should be dashed, dotted or solid
      function SetLineStyle($aType) {
          $this->type = $aType;
      }
  
      // Decide if both major and minor grid should be displayed
      function Show($aShowMajor=true) {
          $this->show=$aShowMajor;
      }
  
      function Stroke($img,$grid) {
          if( !$this->show ) {
              return;
          }
  
          $nbrticks = count($grid[0])/2;
          $nbrpnts = count($grid);
          $img->SetColor($this->grid_color);
          $img->SetLineWeight($this->weight);
  
          for($i=0; $i<$nbrticks; ++$i) {
              for($j=0; $j<$nbrpnts; ++$j) {
                  $pnts[$j*2]=$grid[$j][$i*2];
                  $pnts[$j*2+1]=$grid[$j][$i*2+1];
              }
              for($k=0; $k<$nbrpnts; ++$k ){
                  $l=($k+1)%$nbrpnts;
                  if( $this->type == 'solid' )
                      $img->Line($pnts[$k*2],$pnts[$k*2+1],$pnts[$l*2],$pnts[$l*2+1]);
                  elseif( $this->type == 'dotted' )
                      $img->DashedLine($pnts[$k*2],$pnts[$k*2+1],$pnts[$l*2],$pnts[$l*2+1],1,6);
                  elseif( $this->type == 'dashed' )
                      $img->DashedLine($pnts[$k*2],$pnts[$k*2+1],$pnts[$l*2],$pnts[$l*2+1],2,4);
                  elseif( $this->type == 'longdashed' )
                      $img->DashedLine($pnts[$k*2],$pnts[$k*2+1],$pnts[$l*2],$pnts[$l*2+1],8,6);
              }
              $pnts=array();
          }
      }
  } // Class
  
  
  //===================================================
  // CLASS RadarPlot
  // Description: Plot a radarplot
  //===================================================
  class RadarPlot {
      public $mark=null;
      public $legend='';
      public $legendcsimtarget='';
      public $legendcsimalt='';
      public $csimtargets=array(); // Array of targets for CSIM
      public $csimareas="";   // Resultant CSIM area tags
      public $csimalts=null;   // ALT:s for corresponding target
      private $data=array();
      private $fill=false, $fill_color=array(200,170,180);
      private $color=array(0,0,0);
      private $weight=1;
      private $linestyle='solid';
  
      //---------------
      // CONSTRUCTOR
      function __construct($data) {
          $this->data = $data;
          $this->mark = new PlotMark();
      }
  
      function Min() {
          return Min($this->data);
      }
  
      function Max() {
          return Max($this->data);
      }
  
      function SetLegend($legend) {
          $this->legend=$legend;
      }
  
      function SetLineStyle($aStyle) {
          $this->linestyle=$aStyle;
      }
  
      function SetLineWeight($w) {
          $this->weight=$w;
      }
  
      function SetFillColor($aColor) {
          $this->fill_color = $aColor;
          $this->fill = true;
      }
  
      function SetFill($f=true) {
          $this->fill = $f;
      }
  
      function SetColor($aColor,$aFillColor=false) {
          $this->color = $aColor;
          if( $aFillColor ) {
              $this->SetFillColor($aFillColor);
              $this->fill = true;
          }
      }
  
      // Set href targets for CSIM
      function SetCSIMTargets($aTargets,$aAlts=null) {
          $this->csimtargets=$aTargets;
          $this->csimalts=$aAlts;
      }
  
      // Get all created areas
      function GetCSIMareas() {
          return $this->csimareas;
      }
  
      function Stroke($img, $pos, $scale, $startangle) {
          $nbrpnts = count($this->data);
          $astep=2*M_PI/$nbrpnts;
          $a=$startangle;
  
          for($i=0; $i<$nbrpnts; ++$i) {
  
              // Rotate each non null point to the correct axis-angle
              $cs=$scale->RelTranslate($this->data[$i]);
              $x=round($cs*cos($a)+$scale->scale_abs[0]);
              $y=round($pos-$cs*sin($a));
  
              $pnts[$i*2]=$x;
              $pnts[$i*2+1]=$y;
  
              // If the next point is null then we draw this polygon segment
              // to the center, skip the next and draw the next segment from
              // the center up to the point on the axis with the first non-null
              // value and continues from that point. Some additoinal logic is necessary
              // to handle the boundary conditions
              if( $i < $nbrpnts-1 ) {
                  if( is_null($this->data[$i+1]) ) {
                      $cs = 0;
                      $x=round($cs*cos($a)+$scale->scale_abs[0]);
                      $y=round($pos-$cs*sin($a));
                      $pnts[$i*2]=$x;
                      $pnts[$i*2+1]=$y;
                      $a += $astep;
                  }
              }
  
              $a += $astep;
          }
  
          if( $this->fill ) {
              $img->SetColor($this->fill_color);
              $img->FilledPolygon($pnts);
          }
  
          $img->SetLineWeight($this->weight);
          $img->SetColor($this->color);
          $img->SetLineStyle($this->linestyle);
          $pnts[] = $pnts[0];
          $pnts[] = $pnts[1];
          $img->Polygon($pnts);
          $img->SetLineStyle('solid'); // Reset line style to default
  
          // Add plotmarks on top
          if( $this->mark->show ) {
  			for($i=0; $i < $nbrpnts; ++$i) {
  	            if( isset($this->csimtargets[$i]) ) {
  	                $this->mark->SetCSIMTarget($this->csimtargets[$i]);
  	                $this->mark->SetCSIMAlt($this->csimalts[$i]);
  	                $this->mark->SetCSIMAltVal($pnts[$i*2], $pnts[$i*2+1]);
  	                $this->mark->Stroke($img, $pnts[$i*2], $pnts[$i*2+1]);
  	                $this->csimareas .= $this->mark->GetCSIMAreas();
  	            }
  	            else {
  					$this->mark->Stroke($img,$pnts[$i*2],$pnts[$i*2+1]);
  	            }
              }
          }
  
      }
  
      function GetCount() {
          return count($this->data);
      }
  
      function Legend($graph) {
          if( $this->legend == '' ) {
              return;
          }
          if( $this->fill ) {
              $graph->legend->Add($this->legend,$this->fill_color,$this->mark);
          } else {
              $graph->legend->Add($this->legend,$this->color,$this->mark);
          }
      }
  
  } // Class
  
  //===================================================
  // CLASS RadarGraph
  // Description: Main container for a radar graph
  //===================================================
  class RadarGraph extends Graph {
      public $grid,$axis=null;
      private $posx,$posy;
      private $len;
      private $axis_title=null;
  
      function __construct($width=300,$height=200,$cachedName="",$timeout=0,$inline=1) {
          parent::__construct($width,$height,$cachedName,$timeout,$inline);
          $this->posx = $width/2;
          $this->posy = $height/2;
          $this->len = min($width,$height)*0.35;
          $this->SetColor(array(255,255,255));
          $this->SetTickDensity(TICKD_NORMAL);
          $this->SetScale('lin');
          $this->SetGridDepth(DEPTH_FRONT);
      }
  
      function HideTickMarks($aFlag=true) {
          $this->axis->scale->ticks->SupressTickMarks($aFlag);
      }
  
      function ShowMinorTickmarks($aFlag=true) {
          $this->yscale->ticks->SupressMinorTickMarks(!$aFlag);
      }
  
      function SetScale($axtype,$ymin=1,$ymax=1,$dummy1=null,$dumy2=null) {
          if( $axtype != 'lin' && $axtype != 'log' ) {
              JpGraphError::RaiseL(18003,$axtype);
              //("Illegal scale for radarplot ($axtype). Must be \"lin\" or \"log\"");
          }
          if( $axtype == 'lin' ) {
              $this->yscale = new LinearScale($ymin,$ymax);
              $this->yscale->ticks = new RadarLinearTicks();
              $this->yscale->ticks->SupressMinorTickMarks();
          }
          elseif( $axtype == 'log' ) {
              $this->yscale = new LogScale($ymin,$ymax);
              $this->yscale->ticks = new RadarLogTicks();
          }
  
          $this->axis = new RadarAxis($this->img,$this->yscale);
          $this->grid = new RadarGrid();
      }
  
      function SetSize($aSize) {
          if( $aSize < 0.1 || $aSize>1 ) {
              JpGraphError::RaiseL(18004,$aSize);
              //("Radar Plot size must be between 0.1 and 1. (Your value=$s)");
          }
          $this->len=min($this->img->width,$this->img->height)*$aSize/2;
      }
  
      function SetPlotSize($aSize) {
          $this->SetSize($aSize);
      }
  
      function SetTickDensity($densy=TICKD_NORMAL,$dummy1=null) {
          $this->ytick_factor=25;
          switch( $densy ) {
              case TICKD_DENSE:
                  $this->ytick_factor=12;
                  break;
              case TICKD_NORMAL:
                  $this->ytick_factor=25;
                  break;
              case TICKD_SPARSE:
                  $this->ytick_factor=40;
                  break;
              case TICKD_VERYSPARSE:
                  $this->ytick_factor=70;
                  break;
              default:
                  JpGraphError::RaiseL(18005,$densy);
                  //("RadarPlot Unsupported Tick density: $densy");
          }
      }
  
      function SetPos($px,$py=0.5) {
          $this->SetCenter($px,$py);
      }
  
      function SetCenter($px,$py=0.5) {
          if( $px >= 0 && $px <= 1 ) {
          	$this->posx = $this->img->width*$px;
          }
          else {
          	$this->posx = $px;
          }
          if( $py >= 0 && $py <= 1 ) {
          	$this->posy = $this->img->height*$py;
          }
          else {
          	$this->posy = $py;
          }
      }
  
      function SetColor($aColor) {
          $this->SetMarginColor($aColor);
      }
  
      function SetTitles($aTitleArray) {
          $this->axis_title = $aTitleArray;
      }
  
      function Add($aPlot) {
      	if( $aPlot == null ) {
              JpGraphError::RaiseL(25010);//("Graph::Add() You tried to add a null plot to the graph.");
          }
          if( is_array($aPlot) && count($aPlot) > 0 ) {
              $cl = $aPlot[0];
          }
          else {
              $cl = $aPlot;
          }
  
          if( $cl instanceof Text ) $this->AddText($aPlot);
          elseif( class_exists('IconPlot',false) && ($cl instanceof IconPlot) ) $this->AddIcon($aPlot);
          else {
              $this->plots[] = $aPlot;
          }
      }
  
      function GetPlotsYMinMax($aPlots) {
          $min=$aPlots[0]->Min();
          $max=$aPlots[0]->Max();
          foreach( $this->plots as $p ) {
              $max=max($max,$p->Max());
              $min=min($min,$p->Min());
          }
          if( $min < 0 ) {
              JpGraphError::RaiseL(18006,$min);
              //("Minimum data $min (Radar plots should only be used when all data points > 0)");
          }
          return array($min,$max);
      }
  
      function StrokeIcons() {
      	if( $this->iIcons != null ) {
          	$n = count($this->iIcons);
          	for( $i=0; $i < $n; ++$i ) {
              	$this->iIcons[$i]->Stroke($this->img);
          	}
      	}
      }
  
  	function StrokeTexts() {
          if( $this->texts != null ) {
  			$n = count($this->texts);
              for( $i=0; $i < $n; ++$i ) {
                  $this->texts[$i]->Stroke($this->img);
              }
          }
      }
  
      // Stroke the Radar graph
      function Stroke($aStrokeFileName='') {
  
          // If the filename is the predefined value = '_csim_special_'
          // we assume that the call to stroke only needs to do enough
          // to correctly generate the CSIM maps.
          // We use this variable to skip things we don't strictly need
          // to do to generate the image map to improve performance
          // a best we can. Therefor you will see a lot of tests !$_csim in the
          // code below.
          $_csim = ( $aStrokeFileName === _CSIM_SPECIALFILE );
  
          // We need to know if we have stroked the plot in the
          // GetCSIMareas. Otherwise the CSIM hasn't been generated
          // and in the case of GetCSIM called before stroke to generate
          // CSIM without storing an image to disk GetCSIM must call Stroke.
          $this->iHasStroked = true;
  
          $n = count($this->plots);
          // Set Y-scale
  
          if( !$this->yscale->IsSpecified() && count($this->plots) > 0 ) {
              list($min,$max) = $this->GetPlotsYMinMax($this->plots);
              $this->yscale->AutoScale($this->img,0,$max,$this->len/$this->ytick_factor);
          }
          elseif( $this->yscale->IsSpecified() &&
                  ( $this->yscale->auto_ticks || !$this->yscale->ticks->IsSpecified()) ) {
  
              // The tick calculation will use the user suplied min/max values to determine
              // the ticks. If auto_ticks is false the exact user specifed min and max
              // values will be used for the scale.
              // If auto_ticks is true then the scale might be slightly adjusted
              // so that the min and max values falls on an even major step.
              $min = $this->yscale->scale[0];
              $max = $this->yscale->scale[1];
              $this->yscale->AutoScale($this->img,$min,$max,
                                       $this->len/$this->ytick_factor,
                                       $this->yscale->auto_ticks);
          }
  
          // Set start position end length of scale (in absolute pixels)
          $this->yscale->SetConstants($this->posx,$this->len);
  
          // We need as many axis as there are data points
          $nbrpnts=$this->plots[0]->GetCount();
  
          // If we have no titles just number the axis 1,2,3,...
          if( $this->axis_title==null ) {
              for($i=0; $i < $nbrpnts; ++$i ) {
                  $this->axis_title[$i] = $i+1;
              }
          }
          elseif( count($this->axis_title) < $nbrpnts) {
              JpGraphError::RaiseL(18007);
              // ("Number of titles does not match number of points in plot.");
          }
          for( $i=0; $i < $n; ++$i ) {
              if( $nbrpnts != $this->plots[$i]->GetCount() ) {
                  JpGraphError::RaiseL(18008);
                  //("Each radar plot must have the same number of data points.");
              }
          }
  
          if( !$_csim ) {
          	if( $this->background_image != '' ) {
              	$this->StrokeFrameBackground();
          	}
          	else {
              	$this->StrokeFrame();
              	$this->StrokeBackgroundGrad();
          	}
          }
          $astep=2*M_PI/$nbrpnts;
  
  		if( !$_csim ) {
       		if( $this->iIconDepth == DEPTH_BACK ) {
          		$this->StrokeIcons();
          	}
  
  
  	        // Prepare legends
      	    for($i=0; $i < $n; ++$i) {
          	    $this->plots[$i]->Legend($this);
  	        }
      	    $this->legend->Stroke($this->img);
          	$this->footer->Stroke($this->img);
  		}
  
  		if( !$_csim ) {
  	        if( $this->grid_depth == DEPTH_BACK ) {
  	            // Draw axis and grid
  	            for( $i=0,$a=M_PI/2; $i < $nbrpnts; ++$i, $a += $astep ) {
  	                $this->axis->Stroke($this->posy,$a,$grid[$i],$this->axis_title[$i],$i==0);
  	            }
                  $this->grid->Stroke($this->img,$grid);
  	        }
              if( $this->iIconDepth == DEPTH_BACK ) {
                  $this->StrokeIcons();
              }
  
  		}
  
          // Plot points
          $a=M_PI/2;
          for($i=0; $i < $n; ++$i ) {
              $this->plots[$i]->Stroke($this->img, $this->posy, $this->yscale, $a);
          }
  
          if( !$_csim ) {
              if( $this->grid_depth != DEPTH_BACK ) {
                  // Draw axis and grid
                  for( $i=0,$a=M_PI/2; $i < $nbrpnts; ++$i, $a += $astep ) {
                     $this->axis->Stroke($this->posy,$a,$grid[$i],$this->axis_title[$i],$i==0);
                  }
                  $this->grid->Stroke($this->img,$grid);
              }
  
          	$this->StrokeTitles();
         		$this->StrokeTexts();
         		if( $this->iIconDepth == DEPTH_FRONT ) {
          		$this->StrokeIcons();
          	}
  		}
  
          // Should we do any final image transformation
          if( $this->iImgTrans && !$_csim ) {
              if( !class_exists('ImgTrans',false) ) {
                  require_once('jpgraph_imgtrans.php');
              }
  
              $tform = new ImgTrans($this->img->img);
              $this->img->img = $tform->Skew3D($this->iImgTransHorizon,$this->iImgTransSkewDist,
              $this->iImgTransDirection,$this->iImgTransHighQ,
              $this->iImgTransMinSize,$this->iImgTransFillColor,
              $this->iImgTransBorder);
          }
  
  		if( !$_csim ) {
  	        // If the filename is given as the special "__handle"
  	        // then the image handler is returned and the image is NOT
  	        // streamed back
  	        if( $aStrokeFileName == _IMG_HANDLER ) {
  	            return $this->img->img;
  	        }
  	        else {
  	            // Finally stream the generated picture
  	            $this->cache->PutAndStream($this->img,$this->cache_name,$this->inline,$aStrokeFileName);
  	        }
  		}
      }
  } // Class
  
  /* EOF */
  ?>