Re: draw graph
| From: | Hugh Bothwell | Date: | Wed, 25 Jul 2001 14:06:17 +0000 |
| Subject: | Re: draw graph | ||
| References: | 1 | Groups: | php.db |
| Request: | Send a blank email to php-db+get-10750@lists.php.net to get a copy of this message | ||
"Sommai Fongnamthip" <sommai@thaithanakit.co.th> wrote in message
news:5.1.0.14.2.20010725153241.00a8dc20@langsuan.thaithanakit.co.th...
> Dear,
> How could I draw graph with gd by using PHP code with custom log scale?
How 'bout:
function drawLogGraph($arr) {
$xoffs = 20;
$yoffs = 180;
$drawwidth = 160;
$drawheight = -160;
$logscale = -10; // height of a 10x division
$logscalebase = 1; // '0' on your graph
$numbars = count($arr);
$perbar = $drawwidth / $numbars;
$barwidth = 0.8; // ... fractional draw width
$halfsp = (1 - $barwidth) * 0.5;
$img = ImageCreateFromPNG("graphbackground.png") or die("Could not load
background");
for ($i = 0; $i < $numbars; $i++) {
$barleft = $perbar * ($i + $halfsp);
$barright = $perbar * ($i + 1 - $halfsp);
$bartop = (log10($arr[$i]) - $logscalebase) * $logscale;
ImageFilledRectangle($img, $xoffs + $barleft, $yoffs + $bartop,
$xoffs + $barright, $yoffs, 1);
}
return $img;
}