PHP利用GD库生成折线图

如图，PHPGD库生成折线图；

这里只说原理，至于优化界面，封装数据方法，可自行拆分优化

 0){
		$prenum = $num ;
		$preynum = $ynum ;
	}
	$num = $i * 6 *10;
	$ynum = rand(0,$height);
    imagesetpixel($image, $num , $ynum ,$fff);
	// 设置值
	$str = (string)($height - $ynum);
	if($ynum < $preynum){
		imagestring($image,4,$num,$ynum-20,$str,$fff);
	}else{
		imagestring($image,4,$num,$ynum+20,$str,$fff);

	}
	// imagechar($im, 5, 0, 0, $string, $black);
	// 连线
	// var_dump($str);
	if($i > 0){
		imageline($image,$prenum,$preynum,$num,$ynum,$fff);
	}
	
}

// imageline($image,rand(0,500),rand(0,300),rand(0,500),rand(0,300),create_color($image));

// 4.输出或保存
header('content-type:image/jpg');
imagejpeg($image);


imagedestroy($image);