<?php Header('Content-type: image/png;Charset:utf-8'); //声明图片$im = imagecreate(400,200);//get color.$bg = imagecolorallocate($im,0,0,0);$red = imagecolorallocate($im,255,0,255);$white = imagecolorallocate($im,255,255,255);$arrowX = array(394,97,399,100,394,103);$arrowY = array(197,5,200,0,203,5);               //画曲线for($i=0;$i<380;$i+=0.1){    $x = $i/20;    $y = sin($x);    $y = 100 + 40*$y;    imagesetpixel($im,$i+10,$y,$red);}//画X轴和Y轴imageline($im,0,100,394,100,$white);imageline($im,200,5,200,200,$white);//画坐标titleimagestring($im,4,350,110,'XShaft',$white);//画箭头imagefilledpolygon($im,$arrowX,3,$white);imagefilledpolygon($im,$arrowY,3,$white);imagepng($im);imagedestroy($im);?>

PHP利用GD库画曲线