CakePHP Questions

Hi i'm using jpgraph to display some data in a report. It works fine while the data array is set specifically by me:

$datay=array(2000,3000,5000);

$this->set('datay', $datay);

but what i need to do is set $datay as some query data located in another controller.

So for EG the data may be

$myData = array_sum($data1);

$myData1 = array_sum($data2);

$graphData = array($myData, $myData1);

And i Would like to then have

$datay = $graphData;

But i cant get it to load any data in this way.

Does anyone have any suggestions on this?

thanks!