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

I'm using GRAL for real-time plotting. It's an LGPL Java library. Although it's not as powerful as JFreeChart it has a nicer API. I got a plot up and running in very short time. They also ship a real-time plotting example.

Answer 2

Plot4j supports also real-time plotting!

Answer 3

Live Graph supports real-time rendering.

Answer 4

Check ILOG's JViews - they have a lot of stuff and something might fit your needs. All of them are extremely configurable and quite fast. Not free though.

Answer 5

I've used JFreeChart in a rather complex application that needed to visualize data streams and calculations based on the data. We implemented the ability to visually edit the data plots by mouse and had a very large set of data points. JFreeChart handled it very well.

Unfortunately I was stuck with v0.7, but the newest release are sooo much better when it comes to API clarity. The community is very helpful and the developers are responding to mails too.

If you're doing a web application and don't want to bother with libraries, you can check the Google Chart API. Didn't use it myself, but I started some tests which were very promising.

Answer 6

I found this question when I was googling for open source plotting libraries for java. I wasn't quite happy with the answers posted here so I did some further research on the issue. Although this question has been posted back in 2008 this might still be interesting to someone.

Here is a list of Open Source Charting & Reporting Tools in Java