How to draw sine and cosine curves on pictures using PHP_PHP Tutorial

In the past, I used actionscript to dynamically draw trigonometric function curves. In fact, it is very simple to output trigonometric function curves in PHP.

Copy code The code is as follows:

define("MAX_WIDTH_PIXEL", 600);
define("MAX_HEIGHT_PIXEL", 240);

//Send header information
header("Content-type: image/gif");

//Create image
$img = imageCreate(MAX_WIDTH_PIXEL, MAX_HEIGHT_PIXEL);

//Set color
$bgcolor = imageColorAllocate($img, 0xff, 0xe9, 0xe9);
$red = imageColorAllocate($img, 255, 0, 0);
$blue = imageColorAllocate($img, 0, 0, 255);
$brown = imageColorAllocate($img, 100, 0, 0);
$black = imageColorAllocate($img, 0, 0, 0);

$width = MAX_WIDTH_PIXEL/2; //Width
$height = MAX_HEIGHT_PIXEL/2; //Height

//Create coordinate axis
imageLine($img, $width, 0, $width, MAX_HEIGHT_PIXEL, $black); //y-axis
imageLine($img, 0, $height, MAX_WIDTH_PIXEL, $ height, $black);//x-axis

//Describe function graphics through loops
for($i=0; $i<=MAX_WIDTH_PIXEL; $i++)
{
$y1 = 100 * sin($i/100 * M_PI);
imageSetPixel($img, $i, $height+$y1, $blue);

$y2 = 100 * sin($i/300 * M_PI);
imageSetPixel($img, $i, $height+$y2, $red);

$y3 = 100 * sin($i/300 * M_PI);
imageSetPixel($img, $i, $height-$y3, $brown);
}

//Display graphics
imageGif($img);

//Release resources
imageDestroy($img);
/*==Hermit Bird==*/
?>

http://www.bkjia.com/PHPjc/327471.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/327471.htmlTechArticleI used to use actionscript to dynamically draw trigonometric function curves. In fact, it is very simple to output trigonometric function curves in PHP. Copy the code The code is as follows: ?php define("MAX_WIDTH_PIXEL", 600); define("MA...