Till version 4.0 charts could be exported only as flash, needing an internal server to allow for previewing. Because a chart image could not be created programatically, a chart could not be inserted inside a report.
From 4.0 a chart can be also exported as a jpg image. Using this exporter, now it is possible to insert a chart inside a report (to be seen in HTML, PDF, RTF, EXCEL or saved in XML) :
A pdf result (for chart data analysis part) looks like :
A chart element is similar to an image element, the only difference is that for chart the image is dynamically generated. So, a chart element can be resized similar to an image element.