pieChart.php

<?

function piechart($title, $slice, $itemName, $fsizes=0) {

	function matchset($xx)
	{
	    $arrx = array_values($xx);
	    $i = 0;
	    while (list ($key, $val) = each ($arrx))
		{
			$xy[$i] = $val;
			$i++;
	    }
	    $cnt = $i;
		return $xy;
	}
	$sliced = matchset($slice);
	$countqw = count($sliced);
	
	$ItemNames = matchset($itemName);
	
	// initialize some variables
	$sum = 0;
	$degrees = Array();
	$diameter = 250;
	$radius = $diameter/2;
	
	// calculate sum of slices
	for ($x=0; $x<$countqw ; $x++)
	{
		$sum += $sliced[$x];
	}
	
	// convert each slice into corresponding percentage of 360-degree circle
	$degCount = 0;
	for ($y=0; $y<$countqw; $y++)
	{
		if((($sliced[$y]/$sum) * 360) > '0')
		{
			$degrees[$degCount] = ($sliced[$y]/$sum) * 360;
			$degCount++;
		}	
	}
	
	
	// set up image and colours
	Header("Content-Type: image/png");
	$im = ImageCreate(550, 300);
	
	$black = ImageColorAllocateAlpha($im, 0, 0, 0, 0);
	$white = ImageColorAllocateAlpha($im, 255, 255, 255, 127);
	$hexCode = array("255,153,0","0,204,153","204,255,102","255,102,102","102,204,255","204,153,255","255,0,0","51,0,255","255,51,153","204,0,255","255,255,51","51,255,51","255,102,0");
	// fill image with white
	ImageFill($im, 0, 0, $white);
	
	// draw baseline
	ImageLine($im, 150,150, 225, 150, $black);
	
	for ($z=0; $z<$countqw; $z++)
	{
		// calculate and draw arc corresponding to each slice
		ImageArc($im, 150, 150, $diameter, $diameter, $last_angle,
		($last_angle+$degrees[$z]), $black);
		$last_angle = $last_angle+$degrees[$z];
	
		// calculate coordinate of end-point of each arc by obtaining
		// length of segment and adding radius
		// remember that cos() and sin() return value in radians
		// and have to be converted back to degrees!
		$end_x = round(150 + ($radius * cos($last_angle*pi()/180)));
		$end_y = round(150 + ($radius * sin($last_angle*pi()/180)));
	
		// demarcate slice with another line
		ImageLine($im, 150, 150, $end_x, $end_y, $black);
	}
	
	// this section is meant to calculate the mid-point of each slice
	// so that it can be filled with colour
	
	// initialize some variables
	$prev_angle = 0;
	$pointer = 0;
	
	for ($z=0; $z<$countqw; $z++)
	{
		// to calculate mid-point of a slice, the procedure is to use an angle
		//bisector
		// and then obtain the mid-point of that bisector
		$pointer = $prev_angle + $degrees[$z];
		$this_angle = ($prev_angle + $pointer) / 2;
		$prev_angle = $pointer;
	
		// get end-point of angle bisector
		$end_x = round(150 + ($radius * cos($this_angle*pi()/180)));
		$end_y = round(150 + ($radius * sin($this_angle*pi()/180)));
	
		// given start point (150,150) and end-point above, mid-point can be
		// calculated with standard mid-point formula
		$mid_x = round((150+($end_x))/2);
		$mid_y = round((150+($end_y))/2);
			
		// depending on which slice, fill with appropriate colour
		$hexCodeSplit = explode(',',$hexCode[$z]);
		$WedgeColor = ImageColorAllocate($im, $hexCodeSplit[0],$hexCodeSplit[1],$hexCodeSplit[2]);
		
		ImageFillToBorder($im, $mid_x, $mid_y, $black, $WedgeColor);		
	}
	
	// write string
	ImageString($im,5, 250, 10, "$title", $black);
	
	$red = ImageColorAllocate($im, 255, 153, 153);
	$blue = ImageColorAllocate($im, 0, 0, 255);
	
	// Create Color key and slice description
	$adjPosition = 40;
	
	for ($z=0; $z<$degCount; $z++)
	{
		$percent = ($degrees[$z]/360)*100;
		$percent = round($percent,2);
		$adjPosition = $adjPosition + 15;
		$hexCodeSplit = explode(',',$hexCode[$z]);
		$percentLen = strlen($percent);
		if($percentLen == '4'){$percent = " "."$percent";}
		if($percentLen == '3'){$percent = "  "."$percent";}
		if($percentLen == '2'){$percent = "   "."$percent";}
		if($percentLen == '1'){$percent = "    "."$percent";}
		ImageString($im,2, 300, ($adjPosition+1), "$percent%", $black);
	
		$WedgeColor = ImageColorAllocate($im, $hexCodeSplit[0],$hexCodeSplit[1],$hexCodeSplit[2]);
	
		ImageFilledRectangle($im, 340, $adjPosition, 350, ($adjPosition+10), $black);
		ImageFilledRectangle($im, 341, ($adjPosition+1), 349, ($adjPosition+9), $WedgeColor);
		if($fsizes){
			if($sliced[$z] >= "1000" && $sliced[$z] < "1000000")
			{
				$sliced[$z] = $sliced[$z]/1000;
				$sliced[$z] = sprintf("%01.2f", "$sliced[$z]")."G";
			}	
			else
				$sliced[$z] = "$sliced[$z]"."M";
		}
		$sliceLen = strlen($sliced[$z]);
		if($sliceLen == '5'){$sliced[$z] = " "."$sliced[$z]";}
		if($sliceLen == '4'){$sliced[$z] = "  "."$sliced[$z]";}
		if($sliceLen == '3'){$sliced[$z] = "   "."$sliced[$z]";}
		if($sliceLen == '2'){$sliced[$z] = "    "."$sliced[$z]";}
		if($sliceLen == '1'){$sliced[$z] = "     "."$sliced[$z]";}
	
		ImageString($im,2, 360, ($adjPosition+1), "$sliced[$z]", $black);
		ImageString($im,2, 410, ($adjPosition+1), "$ItemNames[$z]", $black);
	}
	
	// output to browser
	ImagePNG($im);
}
?>