<?php
	/*
		generate a bar graph of data
		@param data : associative array of labels & values
		@param xdim : width (in pixels) of image
		@param ydim : height (in pixels) of image
		@param bar_delta : space between value markings (defaults to 5 evenly spaced points)
	*/
	function bar_graph($data,$xdim,$ydim,$bar_delta=0)
	{
		$handle = imagecreate($xdim,$ydim);
		$background = array(255,255,255);
		$background = imagecolorallocate($handle,$background[0],$background[1],$background[2]);
		$text = imagecolorallocate($handle,0,0,0);
		$lines = imagecolorallocate($handle,255,0,0);
		$bars = imagecolorallocate($handle,100,200,255);
		$min = min(array_values($data));
		$max = max(array_values($data));
		$c = 5;
		while ($bar_delta == 0 && $c)
		{
			$bar_delta = floor($max/$c);
			$c -= 1;
		}
		$y_delta = floor($ydim / ($max/$bar_delta));
		$bar_delta = floor($bar_delta);
		if ($bar_delta == 0) $bar_delta = 1;
		if ($y_delta == 0) $y_delta = 1;
		$cur = $ydim-3;
		$val = $max;
		while ($cur > 0)
		{
			imageline($handle,10,$ydim-$cur+3,$xdim,$ydim-$cur+3,$lines);
			imagestring($handle,1,0,$ydim-$cur,$val,$text);
			$cur -= $y_delta;
			$val -= $bar_delta;
		}
		$padleft = 15;
		$padding = 5;
		$available = $xdim-$padleft-count($data)*$padding;
		$width = $available/count($data);
		$cLeft = $padleft;
		foreach($data as $key=>$value)
		{
			imagefilledrectangle($handle,$cLeft,$ydim-$ydim*$value/$max+3,$cLeft+$width,$ydim,$bars);
			$strwidth = strlen($key)*6;
			$offset = ($width-$strwidth)/2;
			imagestring($handle,3,$cLeft+$offset,$ydim-15,$key,$text);
			$cLeft += $width+$padding;
		}
		header("Content-Type: image/png");
		imagepng($handle);
		imagedestroy($handle);
	}
	function line_graph($data,$xdim,$ydim,$m_m_0=false,$round_to = 1, $MIN = null, $MAX = null, $deltas = null)
	{
		$DELTA_COUNT = 5;
		$handle = imagecreate($xdim,$ydim);
		$background = imagecolorallocate($handle, 255,255,255);
		$text = imagecolorallocate($handle, 0,0,0);
		$datcolors = array(imagecolorallocate($handle,255,0,0), imagecolorallocate($handle,0,255,0), imagecolorallocate($handle, 0,0,255), imagecolorallocate($handle,255,255,0), imagecolorallocate($handle,0,255,255), imagecolorallocate($handle,255,0,255));
		$min = min($data[0]);
		$max = max($data[0]);
		foreach($data as $next) {
			$t = min($next);
			$min = $min < $t ? $min : $t;
			$t = max($next);
			$max = $max > $t ? $max : $t;
		}
		if ($MIN === null)
			$MIN = $min;
		if ($MAX === null)
			$MAX = $max;
		$range = $MAX-$MIN;
		if (!$deltas)
		{
			if ($round_to) {
				if ($MAX%$round_to)
					$MAX = ceil($MAX/$round_to)*$round_to;
				if ($MIN%$round_to)
					$MIN = floor($MIN/$round_to)*$round_to;
			}
			$range = $MAX-$MIN;
			$deltas = $range/$DELTA_COUNT;
			$deltas = $deltas ? $deltas : 1;
		}
		$c = 0;
		$bar_y_delta = floor($ydim/$range)*$scaled;
		if ($m_m_0)
		{
			imagestring($handle,1,0,$ydim-10,round($MIN,3),$text);
			imagestring($handle,1,0,0,round($MAX,3),$text);
		}
		else
			while ($MIN+$c*$deltas <= $MAX)
			{
				imageline($handle,10,$ydim-$bar_y_delta*$c,$xdim,$ydim-$bar_y_delta*$c,$text);
				imagestring($handle,1,0,$ydim-$bar_y_delta*$c,$MIN+($c++)*$deltas,$text);
			}
		$transform = $ydim/$range;
		for ($i = 0 ; $i < count($data) ; $i++)
		{
			$xoffset = ($xdim-10)/(count($data[$i])-1);
			for ($j = 0 ; $j < count($data[$i])-1 ; $j++) {
				imageline($handle,
					$xoffset*$j+10,
					$ydim-($data[$i][$j]-$MIN)*$transform,
					$xoffset*($j+1)+10,
					$ydim-($data[$i][$j+1]-$MIN)*$transform,
					$datcolors[$i]
				);
				if ($data[$i][$j] != $MIN)
					imagefilledellipse($handle,$xoffset*$j+10,$ydim-($data[$i][$j]-$MIN)*$transform,5,5,$datcolors[$i]);
			}
			if ($data[$i][$j] != $MIN)
				imagefilledellipse($handle,$xoffset*$j+10,$ydim-($data[$i][$j]-$MIN)*$transform,5,5,$datcolors[$i]);
		}
		header("Content-Type: image/png");
		imagepng($handle);
		imagedestroy($handle);

	}
?>