PHP生成图表pChart的示例解析

pChart是一个开源的图表生成库，主要涉及3个Class：pChart.class, pData.class, pCache.class，可生成20多种简单或复杂的图表，支持PNG，JPG，GIF通用图片格式。数据源可以来自于Database，CSV，当然也可以手写。使用该程序PHP需要开启GD服务，先来看看pChart的工作流程：

主要分为三步：

* 读取用于生成图表数据（数据库、文件）
* 设计图表样式（圆角、底色等）
* 制作标签、题目、图例并生成图表

下面看一个简单的柱状图表：

代码如下：

<?php
 // Standard inclusions 
 include(\"pChart/pData.class\");
 include(\"pChart/pChart.class\");

 // Dataset definition 
 $DataSet = new pData;
 //图表数据
 $DataSet->AddPoint(array(1,4,-3,2,-3,3,2,1,0,7,4),\"Serie1\");
 $DataSet->AddPoint(array(3,3,-4,1,-2,2,1,0,-1,6,3),\"Serie2\");
 $DataSet->AddPoint(array(4,1,2,-1,-4,-2,3,2,1,2,2),\"Serie3\");
 $DataSet->AddAllSeries();
 $DataSet->SetAbsciseLabelSerie();
 //数据图例
 $DataSet->SetSerieName(\"Microsoft\",\"Serie1\");
 $DataSet->SetSerieName(\"IBM\",\"Serie2\");
 $DataSet->SetSerieName(\"Google\",\"Serie3\");

 // Initialise the graph
 $Test = new pChart(700,230);
 //设置图表尺寸、样式
 $Test->setFontProperties(\"Fonts/tahoma.ttf\",8);
 $Test->setGraphArea(50,30,680,200);
 $Test->drawFilledRoundedRectangle(7,7,693,223,5,240,240,240);
 $Test->drawRoundedRectangle(5,5,695,225,5,230,230,230);
 $Test->drawGraphArea(255,255,255,TRUE);
 $Test->drawScale($DataSet->GetData(),$DataSet->GetDataDescription(),SCALE_NORMAL,150,150,150,TRUE,0,2,TRUE);
 $Test->drawGrid(4,TRUE,230,230,230,50);

 // Draw the 0 line
 $Test->setFontProperties(\"Fonts/MankSans.ttf\",6);
 $Test->drawTreshold(0,143,55,72,TRUE,TRUE);

 // Draw the bar graph
 //柱状图要使用drawBarGraph()
 $Test->drawBarGraph($DataSet->GetData(),$DataSet->GetDataDescription(),TRUE,80);


 // Finish the graph
 //制作图例、标题、字体等属性
 $Test->setFontProperties(\"Fonts/MankSans.ttf\",10);
 $Test->drawLegend(596,150,$DataSet->GetDataDescription(),255,255,255);
 $Test->setFontProperties(\"Fonts/MankSans.ttf\",10);
 $Test->drawTitle(50,22,\"Example\",50,50,50,585);
 
 //生成图表
 $imageFile = \"example12.png\";
 $Test->Render($imageFile);
 echo \'<img src=\"\'.$imageFile.\'\">\';
?>

这个是雷达效果的：

代码：

<?php
 // Standard inclusions 
 include(\"pChart/pData.class\");
 include(\"pChart/pChart.class\");

 // Dataset definition 
 $DataSet = new pData;
 $DataSet->AddPoint(array(\"Memory\",\"Disk\",\"Network\",\"Slots\",\"CPU\"),\"Label\");
 $DataSet->AddPoint(array(6,4,7,4,5),\"Serie1\");
 $DataSet->AddPoint(array(2,3,5,2,4),\"Serie2\");
 $DataSet->AddSerie(\"Serie1\");
 $DataSet->AddSerie(\"Serie2\");
 $DataSet->SetAbsciseLabelSerie(\"Label\");


 $DataSet->SetSerieName(\"Reference\",\"Serie1\");
 $DataSet->SetSerieName(\"Tested computer\",\"Serie2\");

 // Initialise the graph
 $Test = new pChart(400,400);
 $Test->setFontProperties(\"Fonts/tahoma.ttf\",8);
 $Test->drawFilledRoundedRectangle(7,7,393,393,5,240,240,240);
 $Test->drawRoundedRectangle(5,5,395,395,5,230,230,230);
 $Test->setGraphArea(30,30,370,370);
 $Test->drawFilledRoundedRectangle(30,30,370,370,5,255,255,255);
 $Test->drawRoundedRectangle(30,30,370,370,5,220,220,220);

 // Draw the radar graph
 //要使用drawRadarAxis()生成雷达效果
 $Test->drawRadarAxis($DataSet->GetData(),$DataSet->GetDataDescription(),TRUE,20,120,120,120,230,230,230);
 $Test->drawFilledRadar($DataSet->GetData(),$DataSet->GetDataDescription(),50,20);

 // Finish the graph
 $Test->drawLegend(15,15,$DataSet->GetDataDescription(),255,255,255);
 $Test->setFontProperties(\"Fonts/tahoma.ttf\",10);
 $Test->drawTitle(0,22,\"Example\",50,50,50,400);
 
 $imageFile = \"example8.png\";
 $Test->Render($imageFile);
 echo \'<img src=\"\'.$imageFile.\'\">\';
?>

再看几个其他的效果

1，饼图：