Is there a way to change the shape size in a JasperReports chart?

I'm building a Time series based chart that graphs Time -> double value. The chart contains at least 230 points. If I use the "show lines" option the graph doesn't display any lines. If I disselect the "show shapes" 开发者_如何学编程the shames disappear, but there are no dots to where the data is.

How would I change the shapes in the chart to a circular point?

I'd override the renderer's getItemShape() method or invoke setSeriesShape() as required. There's an example here. ShapeUtilities is handy, too.