PHP生成条形图的方法

这篇文章主要介绍了PHP生成条形图的方法,可实现生成柱状的条形图,适用于一些类似柱状图显示报表的场合,具有一定的实用价值,需要的朋友可以参考下

本文实例讲述了PHP生成条形图的方法。分享给大家供大家参考。具体实现方法如下：

<?php 
  // create an array of values for the chart. These values  
  // could come from anywhere, POST, GET, database etc.  
  $values = array(23,32,35,57,12,3,36,54,32,15,43,24,30); 
 
  // now we get the number of values in the array. this will  
  // tell us how many columns to plot  
    $columns  = count($values); 
 
  // set the height and width of the graph image 
 
    $width = 300;  
    $height = 200; 
 
  // Set the amount of space between each column  
    $padding = 5; 
 
  // Get the width of 1 column  
    $column_width = $width / $columns ; 
 
  // set the graph color variables  
    $im        = imagecreate($width,$height);  
    $gray      = imagecolorallocate ($im,0xcc,0xcc,0xcc);  
    $gray_lite = imagecolorallocate ($im,0xee,0xee,0xee);  
    $gray_dark = imagecolorallocate ($im,0x7f,0x7f,0x7f);  
    $white     = imagecolorallocate ($im,0xff,0xff,0xff); 
 
  // set the background color of the graph  
    imagefilledrectangle($im,0,0,$width,$height,$white); 
 
 
  // Calculate the maximum value we are going to plot  
  $max_value = max($values); 
 
  // loop over the array of columns  
    for($i=0;$i<$columns;$i++)  
        { 
    // set the column hieght for each value  
        $column_height = ($height / 100) * (( $values[$i] / $max_value) 
 
*100);  
    // now the coords 
        $x1 = $i*$column_width;  
        $y1 = $height-$column_height;  
        $x2 = (($i+1)*$column_width)-$padding;  
        $y2 = $height; 
 
        // write the columns over the background  
        imagefilledrectangle($im,$x1,$y1,$x2,$y2,$gray); 
 
        // This gives the columns a little 3d effect  
        imageline($im,$x1,$y1,$x1,$y2,$gray_lite);  
        imageline($im,$x1,$y2,$x2,$y2,$gray_lite);  
        imageline($im,$x2,$y1,$x2,$y2,$gray_dark);  
        } 
 
   // set the correct png headers  
   header ("Content-type: image/png");  
  // spit the image out the other end  
  imagepng($im);  
?>

运行效果如下图所示：

希望本文所述对大家的PHP程序设计有所帮助。