Imagegraph

// Functie
<?php
function imagegraph(&$img, $title, $mode, $data) {
  if (!$img || ($mode != 1 && $mode != 2) || count($data) == 0) return false;
  $x = imagesx($img);
  $y = imagesy($img);
  $white = imagecolorallocate($img, 255, 255, 255);
  $black = imagecolorallocate($img, 0, 0, 0);
  $grey = imagecolorallocate($img, 210, 210, 210);
  $darkgrey = imagecolorallocate($img, 170, 170, 170);
  $colors = array();
  $colors[] = imagecolorallocate($img, 255, 0, 0);
  $colors[] = imagecolorallocate($img, 0, 255, 0);
  $colors[] = imagecolorallocate($img, 0, 0, 255);
  $colors[] = imagecolorallocate($img, 255, 255, 0);
  $colors[] = imagecolorallocate($img, 255, 0, 255);
  $colors[] = imagecolorallocate($img, 0, 255, 255);
  imagefill($img, 0, 0, $white);
  imagerectangle($img, 0, 0, $x-1, $y-1, $black); //border
  imagefilledrectangle($img, 30, 15, $x-15, $y-30, $grey); //achtergrond
  imageline($img, 30, 15, 30, $y-30, $black); //y as
  imageline($img, 30, $y-30, $x-15, $y-30, $black); //x as
  $fy = imagefontheight(1);
  $fx = imagefontwidth(1);
  $rasterx = 45;
  while ($rasterx <= $x-15) { //x raster
    imageline($img, $rasterx, $y-31, $rasterx, 15, $darkgrey);
    $rasterx += 15;
  }
  $rastery = $y-45;
  while ($rastery >= 15) { //y raster
    imageline($img, 31, $rastery, $x-15, $rastery, $darkgrey);
    $rastery -= 15;
  }
  $graph = 0;
  while($graph < count($data)) {
    $datax = array_keys($data[$graph]);
    $datay = array_values($data[$graph]);
    if (!isset($largestx) || max($datax) > $largestx) $largestx = max($datax);
    if (!isset($smallestx) || min($datax) < $smallestx) $smallestx = min($datax);
    if (!isset($largesty) || max($datay) > $largesty) $largesty = max($datay);
    if (!isset($smallesty) || min($datay) < $smallesty) $smallesty = min($datay);
    $graph++;
  }
  $numrastx = ($x-45)/30;
  $incx = ($largestx-$smallestx)/$numrastx;
  $numrasty = ($y-45)/30;
  $incy = ($largesty-$smallesty)/$numrasty;
  $txtlocx = 30;
  $i = 0;
  while ($txtlocx <= $x-15) { //x as strings
    imagestringup($img, 1, round($txtlocx-($fy/2)), $y-30+strlen(round($i*$incx+$smallestx, 0))*$fx, round($i*$incx+$smallestx, 0), $black);
    $i++;
    $txtlocx += 30;
  }
  $txtlocy = $y-30;
  $i = 0;
  while ($txtlocy >= 15) { //y as strings
    imagestring($img, 1, 30-strlen(round($i*$incy+$smallesty, 0))*$fx, $txtlocy-round($fy/2), round($i*$incy+$smallesty, 0), $black);
    $i++;
    $txtlocy -= 30;
  }
  $graph = 0;
  while ($graph < count($data)) {
    if (!isset($colors[$graph])) break; //kleuren op :(
    ksort($data[$graph]);
    $datax = array_keys($data[$graph]);
    $datay = array_values($data[$graph]);
    $i = 1;
    while ($i < count($datax)) {
      if ($mode == 1) { //lijn voor graph
        $dotx = ((($x-45)/($largestx-$smallestx))*($datax[$i-1]-$smallestx))+30;
        $dotx2 = ((($x-45)/($largestx-$smallestx))*($datax[$i]-$smallestx))+30;
        if ($largesty != $smallesty) {
          $doty = $y-30-((($y-45)/($largesty-$smallesty))*($datay[$i-1]-$smallesty));
          $doty2 = $y-30-((($y-45)/($largesty-$smallesty))*($datay[$i]-$smallesty));
        } else {
          $doty = $y-30-(($y-45)/2);
          $doty2 = $y-30-(($y-45)/2);
        }
        imageline($img, $dotx, $doty, $dotx2, $doty2, $colors[$graph]);
      } elseif ($mode == 2) { //dots voor graph
        $dotx = ((($x-45)/($largestx-$smallestx))*($datax[$i]-$smallestx))+30;
        if ($largesty != $smallesty) $doty = $y-30-((($y-45)/($largesty-$smallesty))*($datay[$i]-$smallesty));
        else $doty = $y-30-(($y-45)/2);
        imagefilledellipse($img, $dotx, $doty, 3, 3, $colors[$graph]);
      }
      $i++;
    }
    $graph++;
  }
  imagestring($img, 2, 30, 1, $title, $black);
  return true;
}
?>

//Testcode voor voorbeeld
<?php
$data = array();
$i = -50;
while ($i <= 50) {
  $data[0][$i] = sin(0.1*$i)*50;
  $data[1][$i] = cos(0.1*$i)*50;
  $data[2][$i] = sin(0.1*$i+pi())*50;
  $data[3][$i] = cos(0.1*$i+pi())*50;
  $data[4][$i] = $i;
  $data[5][$i] = -$i;
  $i++;
}
$img = imagecreatefromjpeg('/home/jorrizza/pics/boosmannetje.jpg');
$img2 = imagecreate(imagesx($img), imagesy($img));
imagegraph($img2, 'Testgrafiek', 1, $data);
imagecopymerge($img, $img2, 0, 0, 0, 0, imagesx($img2), imagesy($img2), 75);
header('Content-Type: image/png');
imagepng($img);
?>