PHP生成条形图的方法

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：

复制代码 代码如下:<?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。