matplotlib-users Mailing List for matplotlib

On 2/11/11 3:06 PM, Ray Speth wrote:
> Hi,
>
> I wrote a script to generate streamline plots using matplotlib a while
> ago, and this post inspired me to finally clean it up a bit. The code is
> available at http://web.mit.edu/speth/Public/streamlines.py and you can
> see an example of its output at
> http://web.mit.edu/speth/Public/streamlines.png
>
> I'd be happy to have it find a home in matplotlib if it would be useful
> to other people there.
Could you put a license statement on the file you posted? Even if it 
isn't included in matplotlib, I think we would love to include it in 
Sage. I've wanted to have streamline plots in Sage for a long time, and 
your plots look great!
Thanks,
Jason

On Fri, Feb 11, 2011 at 3:06 PM, Ray Speth <sp...@mi...> wrote:
> Hi,
>
> I wrote a script to generate streamline plots using matplotlib a while
> ago, and this post inspired me to finally clean it up a bit. The code is
> available at http://web.mit.edu/speth/Public/streamlines.py and you can
> see an example of its output at
> http://web.mit.edu/speth/Public/streamlines.png
>
> I'd be happy to have it find a home in matplotlib if it would be useful
> to other people there.
>
> Ray
>
>
Ray,
That is absolutely beautiful work there.
At the very least, I would like to see this added to the gallery or the
cookbook. The code is very nicely commented and documented. Just a few
points that come to mind.
First, consider the possibility of using asanyarray() instead of asarray().
The big usecase for asanyarray is the use of masked arrays.
Second, I am personally against call signatures that are just "**kwargs" and
then popping off the arguments at the beginning of the method. So long as
the default value is not a mutable object, then put those arguments in the
call signature with the default values. It is much more IDE and
documentation-friendly this way.
Third, I would think that using plt.gca() would be better than plt.axes()
just in case the user is using subplots. gca() will create an axes if none
exists already.
Lastly, you should do ax.plot() instead of plt.plot() since you have already
retrieved the axes object. This way, in case the axes object passed in is
not the currently active axes, it would still work.
The difficulty in getting this included into matplotlib proper (and the same
goes to the other thread about streamgraphs) is that these plots are done in
an object oriented rather than procedural approach. Personally, I would
like to see (one day) a refactor of matplotlib where everything plotable is
an object that gets placed into the axes object (which, itself is a plotable
that gets placed in a figure...). While the current code isn't too far from
that concept, the interface is ultimately procedural.
@everyone else:
The big reason I see for a future refactor to an object-oriented approach is
that plots are getting more complicated, and we can't just keep on adding
more methods to the axes object. A more object-oriented approach would
allow for complex graphs to be placed into their own modules, and yet still
be treated the same as any other plotting method. It would also make it
easier for others to extend matplotlib's plotting features.
Ben Root

Can anyone share a colormap that goes from bright yellow to
dark blue via green, along the lines of the middle 2/3 of
gist_rainbow?
http://www.scipy.org/Cookbook/Matplotlib/Show_colormaps
Thanks,
Alan Isaac