ayuda en creacion de graficas

[dcreate]

Hola amigos, estoy creando graficas y encontre este codigo en la libreria jpgraph y quisiera saber si se pueden crear mas barras con la misma propiedad q tiene este, intente meter $gbarplot = new GroupBarPlot(array($bplot1,$bplot2)); pero ya no sirve el codigo, espero me puedan ayudar

<?php // content="text/plain; charset=utf-8"
include_once ("jpgraph/jpgraph.php");
include_once ("jpgraph/jpgraph_bar.php");

// Some random data to plot
$datay=array(12,26,9,17,31,8,9);

// Create the graph.
$graph = new Graph(440,440,'auto');
$graph->SetScale("textlin");

// Create a bar pot
$bplot = new BarPlot($datay);

// Create targets for the image maps so that the details are opened in a separate window
$fmtStr = "javascript:window.open('barcsim_details.php?id=%d ','_new','width=500,height=300');void(0)";
$n = count($datay);
$targ=array();
$alts=array();
for($i=0; $i < $n; ++$i) {
$targ[$i] = sprintf($fmtStr,$i+1);
$alts[$i] = 'val=%d';
// Note: The format placeholder val=%d will be replaced by the actual value in the ouput HTML by the
// library so that when the user hoovers the mouse over the bar the actual numerical value of the bar
// will be dísplayed
}
$bplot->SetCSIMTargets($targ,$alts);

// Add plot to graph
$graph->Add($bplot);

// Setup the title, also wih a CSIM area
$graph->title->Set("CSIM with popup windows");
$graph->title->SetFont(FF_FONT2,FS_BOLD);
// Assume we can give more details on the graph
$graph->title->SetCSIMTarget(sprintf($fmtStr,-1),'Title for Bar');

// Send back the HTML page which will call this script again to retrieve the image.
$graph->StrokeCSIM();

?>