Creating a simple bar chart using pChart Library in PHP
[ More ] Dec 28, 2008 | 5 Comments | Posted in PHP, Tech, Web Development |pChart is a charting library for PHP that allows generation of dynamic good looking GD based charts. Ever since I saw a small demo of charts in their website, it was attracted to try this product; I didn’t get a chance until last week.
Installing pChart in XAMPP and in Linux (Ubuntu)
The ‘pChart‘ download comes with a numerous list of files and folders, although you will need only about two major folders. They are
- /pChart
- /Fonts
In XAMPP
You can copy both the folders to your global includes folder, so that they can be accessed from anywhere across the system. Say C:\xampp\php-includes\pChart and
C:\xampp\php-includes\Fonts or you can reference them directly using the full path name. The library includes are usually kept outside the htdocs folder for security reasons.
In Linux (Ubuntu)
You can copy both the folders to your global includes folder, so that they can be accessed from anywhere across the system. Say /var/www/php-includes/pChart and
/var/www/php-includes/fonts or you can reference them directly using the full path name.
In this example of creating a bar chart we will use XAMPP, full paths, whereas the examples provided in the pChart download will tell you about how to use the includes folder option. It is best add the folder to the php include setting, so that it can be referenced from anywhere.
Configuring the pChart charting setup in XAMPP
Now we will start placing the php file that will generate the chart, lets create some folders called
- C:\xampp\htdocs\charting-test\
- C:\xampp\htdocs\charting-test\cache-images\
Now create a file called index.php in charting-test folder that will generate the chart. The generated charts are stored in cache-images folder and can be rendered from that folder.
<?php
define ('CHART_ENGINE_ROOT','C:\\xampp\\php-includes\\');
include_once CHART_ENGINE_ROOT.'pChart\\pChart.class';
include_once CHART_ENGINE_ROOT.'pChart\\pData.class';
$chartFileName = $_SERVER['REQUEST_TIME']."_testChart.png";
$dataRow = Array();
$dataRow[0]['studentName']= "Praveen";
$dataRow[0]['studentMarks']= 52;
$dataRow[1]['studentName']= "Krishna";
$dataRow[1]['studentMarks']= 20;
$dataRow[2]['studentName']= "Joseph";
$dataRow[2]['studentMarks']= 35;
$dataRow[3]['studentName']= "Deepak";
$dataRow[3]['studentMarks']= 26;
$dataRow[4]['studentName']= "Martin";
$dataRow[4]['studentMarks']= 37;
$dataRow[5]['studentName']= "Vijay";
$dataRow[5]['studentMarks']= 19;
// Dataset definition
$DataSet = new pData;
for ($i=0; $i<6; $i++) {
$dispStudName = $dataRow[$i]['studentName'];
$dispStudMarks = $dataRow[$i]['studentMarks'];
$DataSet->AddPoint($dispStudName,"Names");
$DataSet->AddPoint($dispStudMarks,"Marks");
}
$DataSet->AddAllSeries();
$DataSet->RemoveSerie("Names");
$DataSet->SetAbsciseLabelSerie("Names");
$DataSet->SetSerieName("Marks","Marks");
$DataSet->SetYAxisName("Marks");
// Initialise the graph
$Test = new pChart(700,270);
$Test->setFontProperties(CHART_ENGINE_ROOT."Fonts\\tahoma.ttf",9);
$Test->setGraphArea(70,30,680,200);
$Test->drawFilledRoundedRectangle(7,7,693,263,5,240,240,240);
$Test->drawRoundedRectangle(5,5,695,265,5,270,270,270);
$Test->drawGraphArea(255,255,255,TRUE);
$Test->drawScale($DataSet->GetData(),$DataSet->GetDataDescription(),SCALE_NORMAL,150,150,150,TRUE,45,2,TRUE);
$Test->drawGrid(4,TRUE,230,230,230,50);
// Draw the 0 line
$Test->setFontProperties(CHART_ENGINE_ROOT."Fonts\\tahoma.ttf",6);
$Test->drawTreshold(0,143,55,72,TRUE,TRUE);
// Draw the bar graph
$Test->drawBarGraph($DataSet->GetData(),$DataSet->GetDataDescription());
// Finish the graph
$Test->setFontProperties(CHART_ENGINE_ROOT."Fonts\\tahoma.ttf",8);
$Test->drawLegend(575,35,$DataSet->GetDataDescription(),255,255,255);
$Test->setFontProperties(CHART_ENGINE_ROOT."Fonts\\tahoma.ttf",10);
$Test->drawTitle(60,22,"Student Marks Comparision",50,50,50,585);
$Test->Render("cache-images/".$chartFileName);
$Test->ReportWarnings();
$webPrintStr = <<<
<img src="cache-images/$chartFileName" alt="" />
ETEXT;
echo $webPrintStr;
?>
Resulting Chart
The charts are really cool 
