matplotlib-devel Mailing List for matplotlib

I've spent some more time working on the idea of using a common image
renderer for the GUIs. As I mentioned before, this will remain
optional so no need to be concerned about losing support for the
current GTK or WX backend, but this will enable us to add capabilities
to the GUI backends that they may not natively support.
I've been working on the GTKGD backend as a testbed since we already
have the GUI architecture in GTK and the drawing architecture in GD.
This already backend provides additional capabilities to GTK, namely
antialiased lines and arbitrary text rotation. I wrote some C code to
transfer the image from GD->GTK so it is now fast enough to be usable,
though not as fast as the native GTK solution. There are some
performance bottlenecks in GD that I've identified in the profiler so
the current speed can be improved.
David Moore has implemented a paint backend (a libart wrapper).
libart is a sophisticated render engine that is currently used as the
renderer for Gnome Canvas and is ported to all the major platforms.
Although he is waiting on some paint patches he applied to be
incorporated, this provides another candidate backend for a common
image renderer.
I've updated CVS. In setup.py there is a line 'if 0' that needs to be
replaced with 'if 1' to compile the extension module (does anybody
know how to set flags for distutils?) The GTKGD backend now passes
all the regression tests (though there is a color allocation but that
seems to be a gdmodule problem) and serves as a template for GUI
implementers who want to get something up and running fast. With this
approach, the backend writer does not need to implement either a
Renderer or a GraphicsContext. Once you have the GUI architecture
setup, adding a different image renderer is as simple as doing a
importing a different FigureCanvasBackend and writing an image->gui
canvas transfer function.
If there are any brave souls who want to test this out and working,
I'd be much obliged. You'll need the requirements for the GTK and GD
backends installed as described on
http://matplotlib.sourceforge.net/backends.html, including the
gdmodule patch. Let me know if you encounter any compile problems.
JDH

John,
Thanks for the hints.
First I've tried subscribing to the devel list -- sourceforge is sulking
again, so no joy so far, i've cc'ed the list on this, so if it accepts
posts from non-subcribees it should get there.
I've looked a bit at the transforms stuff + things are making a bit more
sense, but I'm still unable to achieve what I'd like.
I think the basic problem is that Line2D and Rectangle are intended to
draw on the axes, whereas what I'd ideally like to do is draw outside
the axes (see the screenshot i sent originally) -- ie instead of doing
what is done with the legend and have it appear somewhere within the
axes of the plot I'd like the table of data to be outside this.
I was hoping I could do things like specify negative y-positions to draw
below the axes, but I now think I'm deluded in thinking this 'cos
matplotlib is smart and every time something gets drawn the axes are
automagically adjusted to make sure the latest lines/rectangles are
included.
I suspect I need some new sort of object to draw outside the axes - can
you confirm that is the case?
Plan B. would be to just live with putting the tables within the plot,
as per the legend, but this doesn't work too well in general 'cos the
table tends to obscure some important part of the plot.
Let me know if this is still hard to understand and I'll try and get
what I have into a state which demonstrates the problem I am running
into.
John