In this episode we talk about everything from image manipulation, generating charts & graphs, classes and frameworks and even home invasions.
The charting libraries I discuss are Fusion Charts and pChart, both are very good libraries and have great documentation on how to get started.
The following is a code snippet that I wrote which takes in an associative array, parses it out for a data label ($a[0]) and a data value ($a[1]) and generates a Fusion compatible XML file.
function fnGenerateXML($scaption, $sxaxis, $syaxis, $adata)
{
if(empty($adata))
die("Empty data set passed to function.");
$sdata = "\n";
foreach($adata as $arow)
$sdata .= " \n";
$sdata .= "";
$sfile_xml = "./chart.xml";
file_put_contents($sfile_xml, $sdata);
return $sfile_xml;
}
The function is called in the following fashion:
$sfile_xml = fnGenerateXML("Caption", "X Lbl", "Y Lbl", $a);
The Fusion Chart is generated using the following method call:
echo renderChartHTML("./Column3D.swf", "$sfile_xml", "",
"ID", 650, 650, false);
Here is some sample code I wrote to generate a graph using pChart:
// Dataset definition
$pData = new pData;
$pData->AddPoint($a1, "s1");
$pData->AddPoint($a2, "s2");
$pData->AddPoint($alabels, "lbl");
$pData->AddSerie("s1");
$pData->AddSerie("s2");
$pData->SetSerieName("s1lbl", "s1");
$pData->SetSerieName("s2lbl", "s2");
$pData->SetYAxisName("Ylbl");
$pData->SetAbsciseLabelSerie("lbl");
// Init graph
$pGraph = new pChart(800, 340);
$pGraph->setFontProperties("./tahoma.ttf",8);
$pGraph->setGraphArea(50,30,680,200);
$pGraph->drawFilledRoundedRectangle(7,7,693,240,5,240,240,240);
$pGraph->drawRoundedRectangle(5,5,695,240,5,260,230,230);
$pGraph->drawGraphArea(255,255,255,TRUE);
$pGraph->drawScale($pData->GetData(),
$pData->GetDataDescription(),SCALE_ADDALL,150,150,150,TRUE,0,2,TRUE);
$pGraph->drawGrid(4,TRUE,230,230,230,50);
// Draw the 0 line
$pGraph->drawTreshold(0,143,55,72,TRUE,TRUE);
// Draw the graph
$pGraph->drawStackedBarGraph($pData->GetData(),
$pData->GetDataDescription(),TRUE);
// Finish
$pGraph->drawLegend(500,40,$pData->GetDataDescription(),255,255,255);
$pGraph->drawTitle(225,22,"Title",0,0,0);
$pGraph->Stroke();
As you can see pChart requires a bit more setup to get going but both are great libraries for getting the job done. Another free option for charting/graphing that we didn’t discuss on the podcast is the Google Chart API.
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Enjoy the show and as always, stay geeky!
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- Nicholas
