$width=200;
$height=200;
Header("Content-type: image/gif");
$im = imagecreate($width,$height);
$white=ImageColorAllocate($im,255,255,255);
$blue=ImageColorAllocate($im,1,18,250);
$red=ImageColorAllocate($im,125,12,89);
$centerx=100;
$centery=100;
for ($x=-100;$x<=100;$x++)
{
for ($sub=500;$sub<=10000;$sub+=500)
{
$new=($x*$x*$x)/$sub;
imagesetpixel ($im, ($centerx+$x), ($centery-$new), $blue);
imagesetpixel ($im, ($centery-$new),($centerx+$x) , $red);
imagesetpixel ($im, ($centerx-$x), ($centery-$new), $red);
imagesetpixel ($im, ($centery+$new),($centerx+$x) , $blue);
}
}
imagePng($im);
ImageDestroy($im);
?>