bad Prfomance on Linux

greiff · Post by **greiff** » Tue Feb 03, 2004 12:25 pm

we have a problem with the performance of JFreeChart on Linux. On Windows 2000 it takes 1 sec to genearate a PNG timeseries chart with 2 series. On our Linux box (same mem and processor) the overall task takes 10 secs.
We are using Jboss as appserver and jdk 1.4.2.
Are there any performance issues on linux ?

thx in advance
Torsten

Post by **david.gilbert** » Wed Feb 04, 2004 11:12 am

I have noticed that Java2D is slower for me on Linux than on Windows (same machine), but I don't know the reason why. And sometimes the difference is as much as a factor of 10 (but usually less).

What type of chart are you drawing? In most places, the JFreeChart code tries to be flexible rather than fast, so it is often possible to make chart-specific alterations to the source code to get better performance. Or if you prefer not to modify the code, switching off anti-aliasing improves speed a lot.

greiff · Post by **greiff** » Thu Feb 05, 2004 1:21 pm

david.gilbert wrote:I have noticed that Java2D is slower for me on Linux than on Windows (same machine), but I don't know the reason why. And sometimes the difference is as much as a factor of 10 (but usually less).

What type of chart are you drawing? In most places, the JFreeChart code tries to be flexible rather than fast, so it is often possible to make chart-specific alterations to the source code to get better performance. Or if you prefer not to modify the code, switching off anti-aliasing improves speed a lot.

Thanks for your reply.
We draw a 2 line timeseries chart (each up to 500 data entries) and a 200 day moving average. How can I switch off anti-aliasing ?

Torsten

Post by **david.gilbert** » Fri Feb 06, 2004 5:43 pm

You can use the setAntiAlias() method in the JFreeChart class. It was deprecated at one point, but I have reinstated it now.

I'm hoping to modify the renderer that draws lines for the time series charts to have an option to store all the small lines that make up a series as a polygon or general path in the renderer state object, then just draw the whole line at the end. I need to do this because when there are a lot of items and the line stroke is dashed, you can't make out the dashes anymore...but I think it may also speed things up a little. It's on the to-do list, anyway.