#229 Contour plot try out


Hello i have used and adapted fortran algorithm for computing contour layout.
see http://www.crm.umontreal.ca/Galerie/ContourPlotApplet_Eng.html for original project.

i have reworked it and created a dataset and a Renderer for JFreeChart.
you have full sources in jar file and you can launch the jar file to see an example.
(you must have jcommon-1.0.14.jar jfreechart-1.0.11.jar in the same dir)

i added two screenshot for those who don't want to download launch the test application.

The code is very, very low on comment for the part that does the computation.
All in all it seems to work correctly and provide a nice alternative to scatter plot for large data.

Any comments is welcome.

Julien Blaize


  • Julien Blaize

    Julien Blaize - 2008-12-15

    jar files with sources

  • Julien Blaize

    Julien Blaize - 2008-12-15

    the contour plot

  • Julien Blaize

    Julien Blaize - 2008-12-15

    same data in scatter plot

  • David Gilbert

    David Gilbert - 2008-12-19

    Hi Julien,

    Nice work, this shows a lot of promise! My first question, though, is: what is the licence of the original code that you've derived it from? I found the link to the MacTech article:


    ...but it doesn't mention any licence explicitly. I'll try to get hold of the ACM article, if it doesn't cost too much, and see what it mentions regarding copyright and licence terms. In the worst case, we could reimplement the algorithm from scratch.

    Sorry to get straight into licence questions, but it is necessary to take some care to ensure that the code going into JFreeChart can be freely licensed under the terms of the GNU Lesser General Public Licence.

    Best regards,

    Dave Gilbert
    JFreeChart Project Leader

  • David Gilbert

    David Gilbert - 2008-12-19
    • assigned_to: nobody --> mungady
  • Julien Blaize

    Julien Blaize - 2008-12-19

    Hi Dave,

    I understand your concerns about the licence. I don't know what could be the licence for the java code from the applet page (montreal). I am not legal expert and cannot give you advice on this, maybe i should have think of this before posting.
    Anyway i think the original fortran code by Snyder is in a book and was written at a time where GPL didn't even exists ... (i have found the fortran code also on the net but can't remenber where)
    Your idea to contact mactech and know the licence for the content of the article seems the best option.

    Maybe i can let you do it ? as my english writing is poor... (i am french and wasn't listening enought in english classes)


  • David Gilbert

    David Gilbert - 2008-12-19

    I have a copy of the Snyder article now, I just needed to pay US$10 to ACM and I have the Fortran code too. There's no mention of the licence, but I will start by reading the details of the algorithm to see if I can understand how it works.



  • Julien Blaize

    Julien Blaize - 2009-07-30


    i have found another applet that contains code for Contour plot. I don't have time right now to implement it as a dataset.
    But the algorithm seems to written in java from the start, so it will be easyier for us to understand.
    the full source is at the bottom.

    Maybe it can help.



Get latest updates about Open Source Projects, Conferences and News.

Sign up for the SourceForge newsletter:

No, thanks