解析PHP生成图表pChart的示例

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：

相关学习推荐：PHP编程从入门到精通

主要分为三步：

1. * 读取用于生成图表数据（数据库、文件）
2. * 设计图表样式（圆角、底色等）
3. * 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：

2, 双座标曲线图：

3, 层叠柱状图：

4, 多图表：

图表的种类已经相当丰富了，具体图表设置请参考

http://pchart.sourceforge.net/documentation.PHP?topic=pChart

::源代码下载::：

http://xiazai.jb51.net/202007/yuanma/pChart_jb51.rar