Polar Plot
Since polar plots are currently (as of 0.9.13) missing in
JFreeChart,
we have created an extension that adds this capability. Our intent is
that they become integrated into JFreeChart. The classes are
not in the JFreeChart packages, but could be easily moved there.
Features
This polar plot package is different than the ones we found in the JFreeChart form
in that they do not use a CategoryDataset but a PolarDataset.
As of this initial release, PolarDataset extends the XYDataset.
Below is a list of features:
- Uses an
XYDataset based dataset instead of a CategoryDataset.
- Allows the user to plot data in (theta, radius) pairs.
- Places text (annotation) in the lower left corner.
- Draws a grid of radial lines (spokes) at every 45 degrees.
- Draws a grid of rings at an auto generated unit depending upon the upper bound of the
RadialAxis.
- Allows the programmer to specify different series of the dataset to be filled.
- Supports Zoom In, Zoom Out, and Auto Range popup menu items.
Code Changes
More work is needed on these classes. In particular, the following are needed:
- Popup menu control of colors and fill status.
- Popup menu control of angular and radius tick units.
- Maybe change
PolarDataset so that it does not implement the XYDataset
but has something more unique. This needs more thought.
We expect to be making changes by March 2004. Please check back.
SEI would appreciate being notified
if you are using this code. Also, if you would like to contribute any changes, that
would be appreciated too.
Source
The source code for the Polar Plot package is provided with the GNU Lesser General Public License
where the intent is that it is integrated into JFreeChart. Also, the source
has an no warranty, so you can't take us to court. :)
Demo
So that others can see the polar plotting package in action, a simple demonstration
application is provided. This demonstration is a Java Web Start application.
It requires a ~700 KB download since it includes the JFreeChart jar files.
The image below shows an example of the demo:
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