Generate bar chart with PHP_PHP tutorial

PHP Generate Bar Chart
Due to overwhelmning the relevant example for Guangdong's needs, the most important thing about this is to generate the bar chart from an array as required

. Of course, these can easily be numbered from any source, as well as put into an array

// create an array of values ​​for the chart. These values ​​
// could come from anywhere, POST, GET, database etc.
$values ​​= array(23,32,35,57,12,3,36,54,32,15,43,24,30) ;

// now we get the number of values ​​in the array. this will
// tell us how many columns to plot
$columns = count($values);

// set the height and width of the graph image

$width = 300;
$height = 200;

// Set the amount of space between each column
$padding = 5;

// Get the width of 1 column
$column_width = $width / $columns ;

// set the graph color variables
$im = imagecreate($width,$height);
$gray = imagecolorallocate ($im,0xcc,0xcc,0xcc);
$gray_lite = imagecolorallocate ($im,0xee,0xee,0xee);
$ gray_dark = imagecolorallocate ($im,0x7f,0x7f,0x7f);
$white = imagecolorallocate ($im,0xff,0xff,0xff);

// set the background color of the graph
imagefilledrectangle($im,0,0,$width,$height,$white);

// Calculate the maximum value we are going to plot
$max_value = max($values) ;

// loop over the array of columns
for($i=0;$i<$columns;$i++)
{
// set the column hieght for each value
$column_height = ($height / 100) * (( $values[$i] / $max_value)

*100);
// now the coords
$x1 = $ i*$column_width;
$y1 = $height-$column_height;
$x2 = (($i+1)*$column_width)-$padding;
$y2 = $height;

// write the columns over the background
imagefilledrectangle($im,$x1,$y1,$x2,$y2,$gray);

// This gives the columns a little 3d effect
imageline($im,$x1,$y1,$x1,$y2,$gray_lite);
imageline($im,$x1,$y2,$x2,$y2,$gray_lite);
imageline($im,$x2,$y1,$x2,$y2,$gray_dark);
}

// set the correct png headers
header ("Content-type: image/png");
// spit the image out the other end
imagepng($im);
?>