Making a scatter-plot of 300k doubles is extremely slow compared to R or Excel with the same data. Perhaps JFreeChart isn't being used optimally?
A single CPU core is utilized 100% during this time. Also after the plot is generated, re-referencing it is quick enough.
Have you got some sample code that tries to do this and is very slow?
I've found that I can get the speed on creating a scatter plot for 300k items down from around 20s on my machine, to almost instant, by switching from an XYSeriesCollection to a DefaultXYDataset. However I need to do more digging to see what the downsides of this would be.
@nathanmesser do you have any code snippets that allows us to use DefaultXYDataset?