Are there any decent free Java data plotting libra

Question

On a recent Java project, we needed a free Java based real-time data plotting utility. After much searching, we found this tool called the Scientific Graphics Toolkit or SGT from NOAA. It seemed pretty robust, but we found out that it wasn't terribly configurable. Or at least not configurable enough to meet our needs. We ended up digging very deeply into the Java code and reverse engineering the code and changing it all around to make the plot tool look and act the way we wanted it to look and act. Of course, this killed any chance for future upgrades from NOAA.

So what free or cheap Java based data plotting tools or libraries do you use?

Followup: Thanks for the JFreeChart suggestions. I checked out their website and it looks like a very nice data charting and plotting utility. I should have made it clear in my original question that I was looking specifically to plot real-time data. I corrected my question above to make that point clear. It appears that JFreeChart support for live data is marginal at best, though. Any other suggestions out there?

Answer 1

jcckit can handle real-time plotting. It's a bear to use though.

I forked it, and made a very simple wrapper around it for non-realtime plotting. The underlying complicated interface can be used directly too.

https://bitbucket.org/hughperkins/easyjcckit

Answer 2

JHandles is an alternative graphics package for Octave (a math package). It is probably worth looking into, but being Octave specific may not have what you need.

-Adam

Answer 3

For real-time plotting you can use QN Plot, JOpenChart or its fork Openchart2.

Answer 4

I used JFreeChart (http://www.jfree.org/jfreechart/) on a previous project. It has some very good built-in capabilities, and the design was WAY extensible so you could always roll your own extension later if you needed some custom chart annotation or wanted an axis to render differently, or whatever. It's definitely worth checking out.