matplotlib-devel Mailing List for matplotlib (Page 10)

On Sat, Jul 19, 2008 at 9:48 PM, Ryan May <rm...@gm...> wrote:
> Ok, thanks for the vote of confidence. My (newly created) ID is: ryanmay
Alright, you're now set up for commits. Keep working closely with
Eric and Jeff and the rest of us on the functionality you are adding.
Welcome aboard!
JDH

John Hunter wrote:
> On Sat, Jul 19, 2008 at 9:30 PM, Ryan May <rm...@gm...> wrote:
>> Take this one instead. I missed some imports on the last one (oops).
> 
> Hey Ryan -- the code you have been contributing is certainly high
> quality, and I am happy to give you commit rights if you send me your
> sf id. You should still post here for anything significant so we can
> review and provide input/feedback, but we'd be happy to have you
> making contributions directly.
Ok, thanks for the vote of confidence. My (newly created) ID is: ryanmay
Ryan
-- 
Ryan May
Graduate Research Assistant
School of Meteorology
University of Oklahoma

On Sat, Jul 19, 2008 at 9:30 PM, Ryan May <rm...@gm...> wrote:
> Take this one instead. I missed some imports on the last one (oops).
Hey Ryan -- the code you have been contributing is certainly high
quality, and I am happy to give you commit rights if you send me your
sf id. You should still post here for anything significant so we can
review and provide input/feedback, but we'd be happy to have you
making contributions directly.
JDH

On Sat, Jul 19, 2008 at 8:02 PM, Eric Firing <ef...@ha...> wrote:
> We might want to consider, however, whether such extensive changes
> should be made immediately *before* a "bugfix" release. I think John is
> trying to get one out. I am already a little nervous about other recent
> and impending changes in this context. (Your idea of a branch was a
Although I may have used the phrase "bugfix release" many times in the
past, I want to clarify my thinking on this. I distinguish between
point releases and major releases. With the exception of the
maintenance branch, on which the *only* changes should be bugfixes, I
expect every point release to have new features and bugfixes. When we
decide to bump the major version is of course subjective, but it
normally comes when a number of significant features have been
introduced, and it should be comparatively rare, 2 to 4 times a year
or so. But I expect and want new features in every point release.
We are fortunate that we have a lot of developers, and Charlie is a
very responsive release manager. I would rather err on the side of
getting new features out, tested to the best of our abilities, with
the understanding that if we break something important we will roll
out a point release that fixes a critical bug within 12 to 24 hours,
and hide the broken release in the mean time. Release early, release
often.
My aversion to branches stems not from the weaknesses in svn merge,
which may be better in hg or other version control systems. The
reason I wnat people contributing to the trunk is that I want as many
people testing and using the code as possible so we can find and fix
the bugs before they are released. While Michael's transforms
refactoring was so significant that it absolutely required a branch,
we did not start finding the bugs until we made his branch the trunk,
and even then did not find the bulk of them. We found them when we
released the code. More tests will help, and we should have as many
tests as we can muster, but until we have bullet-proof tests we have
to leverage our developers and users as testers.
The only short term pressure for a point release is coming from
debian, because they are having some trouble with our last point
release. Because debian is an important platform, I want to get a
point release out that satisfies their problems ASAP, but not before
we are ready. Whether this is next week or next month or next year
will depend on whether the code is ready (I hear echos of Orson Welles
in the old Paul Masson commercial, "We will sell no wine, before it's
time").
In the case of the contouring enhancements, they're not ready, so
we'll wait. In the situation where debian or some other important
vendor has a freeze deadline with a critical problem that needs
fixing, we can always do a branch off the last point release that
fixes just the required bugs. Sandro can keep us appraised if such a
deadline is approaching for 0.98.2.
JDH

John Hunter wrote:
> On Sat, Jul 19, 2008 at 8:58 PM, Ryan May <rm...@gm...> wrote:
>> Hi,
>>
>> In integrating my barbs work, I'm having trouble that causes a circular
>> import. I used delete_masked_points from axes. The problem here is that
>> axes imports quiver (where I put barbs) which then has to (in some form)
>> import axes to get delete_masked_points. Anyone have something I'm
>> missing here? Or can I move delete_masked_points to a better location?
> 
> mlab or cbook would be fine
> 
> JDH
Take this one instead. I missed some imports on the last one (oops).
Ryan
-- 
Ryan May
Graduate Research Assistant
School of Meteorology
University of Oklahoma

John Hunter wrote:
> On Sat, Jul 19, 2008 at 8:58 PM, Ryan May <rm...@gm...> wrote:
>> Hi,
>>
>> In integrating my barbs work, I'm having trouble that causes a circular
>> import. I used delete_masked_points from axes. The problem here is that
>> axes imports quiver (where I put barbs) which then has to (in some form)
>> import axes to get delete_masked_points. Anyone have something I'm
>> missing here? Or can I move delete_masked_points to a better location?
> 
> mlab or cbook would be fine
> 
> JDH
Here's a patch to do just that.
Ryan
-- 
Ryan May
Graduate Research Assistant
School of Meteorology
University of Oklahoma

John Hunter wrote:
> On Sat, Jul 19, 2008 at 8:58 PM, Ryan May <rm...@gm...> wrote:
>> Hi,
>>
>> In integrating my barbs work, I'm having trouble that causes a circular
>> import. I used delete_masked_points from axes. The problem here is that
>> axes imports quiver (where I put barbs) which then has to (in some form)
>> import axes to get delete_masked_points. Anyone have something I'm
>> missing here? Or can I move delete_masked_points to a better location?
> 
> mlab or cbook would be fine
> 
cbook seems like a better home for utility functions like this.
Eric

On Sat, Jul 19, 2008 at 8:58 PM, Ryan May <rm...@gm...> wrote:
> Hi,
>
> In integrating my barbs work, I'm having trouble that causes a circular
> import. I used delete_masked_points from axes. The problem here is that
> axes imports quiver (where I put barbs) which then has to (in some form)
> import axes to get delete_masked_points. Anyone have something I'm
> missing here? Or can I move delete_masked_points to a better location?
mlab or cbook would be fine
JDH

Hi,
In integrating my barbs work, I'm having trouble that causes a circular 
import. I used delete_masked_points from axes. The problem here is that 
axes imports quiver (where I put barbs) which then has to (in some form) 
import axes to get delete_masked_points. Anyone have something I'm 
missing here? Or can I move delete_masked_points to a better location?
Ryan
-- 
Ryan May
Graduate Research Assistant
School of Meteorology
University of Oklahoma

David,
I am reverting your changes to contour.py; that is, I am taking it back 
to 5689. The problem is that running contour_demo.py, below, fails. 
Some index accounting somewhere is getting fouled up. I don't have time 
to investigate.
When you have it straightened out you can put the changes back, so this 
is just a brief setback.
We might want to consider, however, whether such extensive changes 
should be made immediately *before* a "bugfix" release. I think John is 
trying to get one out. I am already a little nervous about other recent 
and impending changes in this context. (Your idea of a branch was a 
good one in concept, but maybe a pain and more trouble than it is worth 
with svn. Too bad we aren't using something nice like Mercurial. Now, 
that comment should push a few buttons.)
Eric
In [1]:run contour_demo.py
---------------------------------------------------------------------------
IndexError Traceback (most recent call last)
/home/efiring/programs/py/mpl/mpl_trunk/examples/pylab_examples/contour_demo.py 
in <module>()
 82 inline=1,
 83 fmt='%1.1f',
---> 84 fontsize=14)
 85
 86 # make a colorbar for the contour lines
/usr/local/lib/python2.5/site-packages/matplotlib/pyplot.pyc in 
clabel(*args, **kwargs)
 1698 hold(h)
 1699 try:
-> 1700 ret = gca().clabel(*args, **kwargs)
 1701 draw_if_interactive()
 1702 except:
/usr/local/lib/python2.5/site-packages/matplotlib/axes.pyc in 
clabel(self, CS, *args, **kwargs)
 5996
 5997 def clabel(self, CS, *args, **kwargs):
-> 5998 return CS.clabel(*args, **kwargs)
 5999 clabel.__doc__ = mcontour.ContourSet.clabel.__doc__
 6000
/usr/local/lib/python2.5/site-packages/matplotlib/contour.pyc in 
clabel(self, *args, **kwargs)
 150 blocking_contour_labeler(inline)
 151 else:
--> 152 self.labels(inline)
 153
 154 self.label_list = cbook.silent_list('text.Text', self.cl)
/usr/local/lib/python2.5/site-packages/matplotlib/contour.pyc in 
labels(self, inline)
 451 if self.print_label(slc,lw):
 452 x,y, rotation, ind = 
self.locate_label(slc, lw)
--> 453 self.add_label(x,y,rotation,icon)
 454
 455 if inline:
/usr/local/lib/python2.5/site-packages/matplotlib/contour.pyc in 
add_label(self, x, y, rotation, icon)
 364 verticalalignment='center')
 365
--> 366 color = 
self.label_mappable.to_rgba(self.label_cvalues[icon],
 367 alpha=self.alpha)
 368
IndexError: index out of bounds
 > 
/usr/local/lib/python2.5/site-packages/matplotlib/contour.py(366)add_label()
 365
--> 366 color = 
self.label_mappable.to_rgba(self.label_cvalues[icon],
 367 alpha=self.alpha)
ipdb> icon
7
ipdb> self.label_cvalues
array([-1. , -0.6, -0.2, 0.2, 0.6, 1. , 1.4])

Eric Firing wrote:
> Ryan May wrote:
> 
>> Eric Firing wrote:
>> 
>>> Ryan May wrote:
>>> 
>>>> Hi,
>>>>
>>>> In looking over trying to support masked arrays in wind barbs, I noticed
>>>> a problem. I had originally copied the model of quiver, wherein masked
>>>> arrays are supported for U,V, and color, but not for X,Y. This stems
>>>> from the seemingly nonsensical nature of masking a location. 
>>>> However, if nothing is drawn for a location X,Y where U,V are masked, 
>>>> this would seemingly lead to a problem where the locations and the 
>>>> things to be drawn get out of phase. Am I missing something here? 
>>>> Eric, did I miss some magic somewhere in quiver that handles this?
>>>> 
>> >>
>> 
>>> There is no magic; we are not compressing or otherwise extracting the 
>>> valid values, but are leaving the masking of U and V in place through 
>>> the creation of the arrow vertices. It is the PolyCollection.draw() 
>>> method that is then handling the masking.
>>>
>>> Now, having said that, and having traced through the code, I am not 
>>> at all sure that everything in collections is still working correctly 
>>> as described; I will have to look a bit more.
>>>
>>> Note that the path module itself can handle masking now, so masked 
>>> arrays sometimes get passed all the way through to it.
>>> 
>> So you mean the list/array of vertices can contain masked values?
>> 
>
> Yes. But again, trying to trace data values through various paths in 
> the code, it can be hard to keep track of what assumptions are being 
> made at each stage. I think the present intention is that masked values 
> are passed through, but I also think I saw a recent code addition 
> (maybe...) that does not do this. I need to check.
>
> 
>>> Quiver and windbarb could use the axes.delete_masked_points function 
>>> right at the start, and this might be a good change to make, except 
>>> that it is inconsistent with using the present set_UVC method to 
>>> update arrows at constant locations.
>>> 
>> delete_masked_points() looks to me like a sane way to go. I'll update 
>> my masked handling to use this.
>> 
>
> It can be OK if your windbarb is intended as a one-shot instance--that 
> is, the user makes another one if the data change--which is probably OK.
>
> delete_masked_points looks to me like it has its own problems in the 
> whole mpl-with-units context, including a recent change that I suspect 
> breaks the handling of datetime inputs, but I don't think that any 
> changes or cleanups will affect your use of it.
I suspect that your concern may be referring to my recent change. I
started some unit tests for delete_masked_points() (in
unit/axes_unit.py) when I made the modifications, so if you have use
cases, put 'em in there...
-Andrew

Thanks for the help, Ryan and Eric.
On Sat, Jul 19, 2008 at 7:27 PM, Eric Firing <ef...@ha...> wrote:
> Ryan,
>
> Thanks. I will take care of this one way or another, but I want to see
> whether we really need both _uniform_offsets and _offsets.
>
> Eric
>
> Ryan May wrote:
>> John Hunter wrote:
>>> On Thu, Jul 17, 2008 at 10:28 PM, Ryan May <rm...@gm...> wrote:
>>>
>>>> I helped Eric out with this offline, and obviously set_array is for the
>>>> colors, but the only solution we could come up with was to directly
>>>> reset the PolyCollection._offsets member. This seems a little hacky.
>>>> Is there any reason that there is not an set_offsets() (or something
>>>> like it)? Any reason why I shouldn't code up a patch?
>>>
>>> No, I can't thing of any reason why this attribute should not be
>>> publicly settable, so patch away.
>>
>> Here's an updated version of the patch so that the doctring actually
>> makes sense.
>>
>> Ryan
>>

Eric Firing wrote:
>>> Quiver and windbarb could use the axes.delete_masked_points function 
>>> right at the start, and this might be a good change to make, except 
>>> that it is inconsistent with using the present set_UVC method to 
>>> update arrows at constant locations.
>>
>> delete_masked_points() looks to me like a sane way to go. I'll update 
>> my masked handling to use this.
> 
> It can be OK if your windbarb is intended as a one-shot instance--that 
> is, the user makes another one if the data change--which is probably OK.
> 
> delete_masked_points looks to me like it has its own problems in the 
> whole mpl-with-units context, including a recent change that I suspect 
> breaks the handling of datetime inputs, but I don't think that any 
> changes or cleanups will affect your use of it.
What I've tried to do is keep copies of the original data passed in, and 
when updating UV or offsets, use delete_masked_points to keep them lined 
 up as appropriate. Does this sound reasonable? It doesn't look too 
bad, and still keeps an interface that allows updating.
Ryan
-- 
Ryan May
Graduate Research Assistant
School of Meteorology
University of Oklahoma

Ryan May wrote:
> Eric Firing wrote:
>> Ryan May wrote:
>>> Hi,
>>>
>>> In looking over trying to support masked arrays in wind barbs, I noticed
>>> a problem. I had originally copied the model of quiver, wherein masked
>>> arrays are supported for U,V, and color, but not for X,Y. This stems
>>> from the seemingly nonsensical nature of masking a location. 
>>> However, if nothing is drawn for a location X,Y where U,V are masked, 
>>> this would seemingly lead to a problem where the locations and the 
>>> things to be drawn get out of phase. Am I missing something here? 
>>> Eric, did I miss some magic somewhere in quiver that handles this?
> >>
>> There is no magic; we are not compressing or otherwise extracting the 
>> valid values, but are leaving the masking of U and V in place through 
>> the creation of the arrow vertices. It is the PolyCollection.draw() 
>> method that is then handling the masking.
>>
>> Now, having said that, and having traced through the code, I am not 
>> at all sure that everything in collections is still working correctly 
>> as described; I will have to look a bit more.
>>
>> Note that the path module itself can handle masking now, so masked 
>> arrays sometimes get passed all the way through to it.
> 
> So you mean the list/array of vertices can contain masked values?
Yes. But again, trying to trace data values through various paths in 
the code, it can be hard to keep track of what assumptions are being 
made at each stage. I think the present intention is that masked values 
are passed through, but I also think I saw a recent code addition 
(maybe...) that does not do this. I need to check.
> 
>>
>> Quiver and windbarb could use the axes.delete_masked_points function 
>> right at the start, and this might be a good change to make, except 
>> that it is inconsistent with using the present set_UVC method to 
>> update arrows at constant locations.
> 
> delete_masked_points() looks to me like a sane way to go. I'll update 
> my masked handling to use this.
It can be OK if your windbarb is intended as a one-shot instance--that 
is, the user makes another one if the data change--which is probably OK.
delete_masked_points looks to me like it has its own problems in the 
whole mpl-with-units context, including a recent change that I suspect 
breaks the handling of datetime inputs, but I don't think that any 
changes or cleanups will affect your use of it.
Eric
> 
> Ryan
> 

Ryan,
Thanks. I will take care of this one way or another, but I want to see 
whether we really need both _uniform_offsets and _offsets.
Eric
Ryan May wrote:
> John Hunter wrote:
>> On Thu, Jul 17, 2008 at 10:28 PM, Ryan May <rm...@gm...> wrote:
>>
>>> I helped Eric out with this offline, and obviously set_array is for the
>>> colors, but the only solution we could come up with was to directly
>>> reset the PolyCollection._offsets member. This seems a little hacky.
>>> Is there any reason that there is not an set_offsets() (or something
>>> like it)? Any reason why I shouldn't code up a patch?
>>
>> No, I can't thing of any reason why this attribute should not be
>> publicly settable, so patch away.
> 
> Here's an updated version of the patch so that the doctring actually 
> makes sense.
> 
> Ryan
> 
> 
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John Hunter wrote:
> On Thu, Jul 17, 2008 at 10:28 PM, Ryan May <rm...@gm...> wrote:
> 
>> I helped Eric out with this offline, and obviously set_array is for the
>> colors, but the only solution we could come up with was to directly
>> reset the PolyCollection._offsets member. This seems a little hacky.
>> Is there any reason that there is not an set_offsets() (or something
>> like it)? Any reason why I shouldn't code up a patch?
> 
> No, I can't thing of any reason why this attribute should not be
> publicly settable, so patch away.
Here's an updated version of the patch so that the doctring actually 
makes sense.
Ryan
-- 
Ryan May
Graduate Research Assistant
School of Meteorology
University of Oklahoma

Jeff Whitaker wrote:
> John: Well, I hit one snag. One file in natgrid has this comment in it.
> 
> /*
> * The code in this file is based on code written and
> * copyrighted (C) by Dave Watson. Dr. Watson retains the
> * copyright to his original code. Augmentations and changes
> * to Dr. Watson's code are copyrighted (C) by UCAR, 1997.
> */
> 
> The NCAR folks have not been able to contact the fellow, and suspect he 
> may have passed on. I can't verify this though. Do you see this as a 
> problem?
It was for me. That's why I wrote scikits.delaunay in the first place. That, and 
the nngridr code's an uncommented mass of nested ifs.
-- 
Robert Kern
"I have come to believe that the whole world is an enigma, a harmless enigma
 that is made terrible by our own mad attempt to interpret it as though it had
 an underlying truth."
 -- Umberto Eco

Eric Firing wrote:
> Ryan May wrote:
>> Hi,
>>
>> In looking over trying to support masked arrays in wind barbs, I noticed
>> a problem. I had originally copied the model of quiver, wherein masked
>> arrays are supported for U,V, and color, but not for X,Y. This stems
>> from the seemingly nonsensical nature of masking a location. However, 
>> if nothing is drawn for a location X,Y where U,V are masked, this 
>> would seemingly lead to a problem where the locations and the things 
>> to be drawn get out of phase. Am I missing something here? Eric, did 
>> I miss some magic somewhere in quiver that handles this?
 >>
> There is no magic; we are not compressing or otherwise extracting the 
> valid values, but are leaving the masking of U and V in place through 
> the creation of the arrow vertices. It is the PolyCollection.draw() 
> method that is then handling the masking.
> 
> Now, having said that, and having traced through the code, I am not at 
> all sure that everything in collections is still working correctly as 
> described; I will have to look a bit more.
> 
> Note that the path module itself can handle masking now, so masked 
> arrays sometimes get passed all the way through to it.
So you mean the list/array of vertices can contain masked values?
> 
> Quiver and windbarb could use the axes.delete_masked_points function 
> right at the start, and this might be a good change to make, except that 
> it is inconsistent with using the present set_UVC method to update 
> arrows at constant locations.
delete_masked_points() looks to me like a sane way to go. I'll update 
my masked handling to use this.
Ryan
-- 
Ryan May
Graduate Research Assistant
School of Meteorology
University of Oklahoma

Ryan May wrote:
> John Hunter wrote:
>> Fernando and Gael proposed supporting a backend fallback option so the
>> user could express the intention: use my default backend unless I
>> happen to be in an incompatible user interface environment and then
>> just choose the most sensible thing. Users who do not want this magic
>> can simply turn the fallback option off. This behavior will only be
>> triggered if
>>
>> 1) the fallback option is on (it will be by default)
>> 2) the user is running mpl in an environment in which a user
>> interface already has a running mainloop
>> 3) the default backend is known to be incompatible. Eg, if the
>> default backend is PS, nothing will happen.
>>
>> I think the proposed changes are reasonable.
>>
> +1
I agree. Sounds like progress.
Eric
> 
> Ryan
> 

Ryan May wrote:
> Hi,
> 
> In trying to add a symbol for an empty wind barb, I ran into problem. 
> Traditionally, a smaller, non-filled circle is used for low wind speeds 
> when doing a barb plot. I can draw the circle easily as a polygon, 
> using CirclePolygon from patches, but unfortunately, the fill color for 
> this polygon ends up being the same as the color of the flags on the 
> barbs. Therefore, as currently implemented, the only way to have 
> unfilled circles is to have unfilled flags.
> 
> The only technical solution I can think of here is to have separate 
> collections for the circles and the polygons. Unfortunately, I have no 
> idea how to begin to do that within a class that inherits from 
> collections. Another option would be to somehow manually set the fill 
> colors on the circles after the collection is initialized. Anyone have 
> suggestions on how to make this work, or maybe a better technical solution.
Ryan,
Yes, this would require some bigger changes. Instead of inheriting from 
PolyCollection, it would have to contain two collections, or a 
collection and a Line2D with markers.
An alternative would be to override the PolyCollection.draw() method 
with a near-copy, but with logic added right before the renderer call to 
 set the alpha (column 3) of the rgba array to zero for the circles.
A better way might be to modify the original draw method to use 
self.get_facecolors() instead of self._facecolors; then one could 
override the get_facecolors method, which would require much less code.
Eric
> 
> Jeff, how aesthetically displeasing do you think it would be to have 
> small (possibly colored) circles to represent the low winds instead of 
> the traditional (somewhat larger) hollow circle? It would make it 
> impossible to do sky cover in a traditional surface map, but maybe 
> Z-ordering could be used to hack around it.
> 
> Thoughts,
> 
> Ryan
> 

Ryan May wrote:
> Hi,
> 
> In looking over trying to support masked arrays in wind barbs, I noticed
> a problem. I had originally copied the model of quiver, wherein masked
> arrays are supported for U,V, and color, but not for X,Y. This stems
> from the seemingly nonsensical nature of masking a location. However, 
> if nothing is drawn for a location X,Y where U,V are masked, this would 
> seemingly lead to a problem where the locations and the things to be 
> drawn get out of phase. Am I missing something here? Eric, did I miss 
> some magic somewhere in quiver that handles this?
> 
> Ryan
> 
Ryan,
There is no magic; we are not compressing or otherwise extracting the 
valid values, but are leaving the masking of U and V in place through 
the creation of the arrow vertices. It is the PolyCollection.draw() 
method that is then handling the masking.
Now, having said that, and having traced through the code, I am not at 
all sure that everything in collections is still working correctly as 
described; I will have to look a bit more.
Note that the path module itself can handle masking now, so masked 
arrays sometimes get passed all the way through to it.
Quiver and windbarb could use the axes.delete_masked_points function 
right at the start, and this might be a good change to make, except that 
 it is inconsistent with using the present set_UVC method to update 
arrows at constant locations.
Eric

Hi,
As promised, here's a short patch to add get_offsets() and set_offsets() 
to the Collections() base class. I tried to make it do the right thing 
with regard to _offsets vs. _uniform_offsets, depending on whether 
_uniform_offsets is None. I also had tried to make __init__ use 
set_offsets, but that proved to be too much of a hassle for too little 
code reuse.
Comments?
Ryan
-- 
Ryan May
Graduate Research Assistant
School of Meteorology
University of Oklahoma

John Hunter wrote:
> Fernando and Gael proposed supporting a backend fallback option so the
> user could express the intention: use my default backend unless I
> happen to be in an incompatible user interface environment and then
> just choose the most sensible thing. Users who do not want this magic
> can simply turn the fallback option off. This behavior will only be
> triggered if
> 
> 1) the fallback option is on (it will be by default)
> 2) the user is running mpl in an environment in which a user
> interface already has a running mainloop
> 3) the default backend is known to be incompatible. Eg, if the
> default backend is PS, nothing will happen.
> 
> I think the proposed changes are reasonable.
> 
+1
Ryan
-- 
Ryan May
Graduate Research Assistant
School of Meteorology
University of Oklahoma

Hi,
In trying to add a symbol for an empty wind barb, I ran into problem. 
Traditionally, a smaller, non-filled circle is used for low wind speeds 
when doing a barb plot. I can draw the circle easily as a polygon, 
using CirclePolygon from patches, but unfortunately, the fill color for 
this polygon ends up being the same as the color of the flags on the 
barbs. Therefore, as currently implemented, the only way to have 
unfilled circles is to have unfilled flags.
The only technical solution I can think of here is to have separate 
collections for the circles and the polygons. Unfortunately, I have no 
idea how to begin to do that within a class that inherits from 
collections. Another option would be to somehow manually set the fill 
colors on the circles after the collection is initialized. Anyone have 
suggestions on how to make this work, or maybe a better technical solution.
Jeff, how aesthetically displeasing do you think it would be to have 
small (possibly colored) circles to represent the low winds instead of 
the traditional (somewhat larger) hollow circle? It would make it 
impossible to do sky cover in a traditional surface map, but maybe 
Z-ordering could be used to hack around it.
Thoughts,
Ryan
-- 
Ryan May
Graduate Research Assistant
School of Meteorology
University of Oklahoma

On Sat, Jul 19, 2008 at 1:05 AM, Gael Varoquaux
<gae...@no...> wrote:
> It turns out it was only in the GTK backend, and quite trivial to
> correct. Attached is a new patch, including this correction.
Hey Gael, this is starting to look reasonable. I know implementing
these checks, such as detecting whether the mainloop is active, can be
a hassle, so thanks for taking the time to write against so many
environments. We may want to make take the logic you've provided and
encapsulate them in the backend methods to make them more easily
recognizable, fixable and reusable. Eg, each unser interface backend
would provide a "mainloop_running" method. You could then access this
in pyplot to support your fallback logic, and also we could use it in
"show" to make sure we don't try and start mainloops that are already
running.
One thing notice in your patch is that when it comes time to check for
tk, you import tkinter and then do nothing with it. I assume this is
a placeholder until you figure out what you want to do?
For a little background, Fernando, Gael and I talked about this
problem a bit over the phone yesterday. The use case they are trying
to address is that people may be wanting to use more than one
application, at different times or at the same time, that have
embedded python shells. With all the work going on making ipython
frontends for wx, qt and gtk, it is not unreasonable to assume that
there ill soon be multiple IDEs or other environment in which one
might want to import and use pylab. Since we only support one default
backend, and it is dificult and onerous for the user to constantly
modify their rc depending on what application they may be launching,
Fernando and Gael proposed supporting a backend fallback option so the
user could express the intention: use my default backend unless I
happen to be in an incompatible user interface environment and then
just choose the most sensible thing. Users who do not want this magic
can simply turn the fallback option off. This behavior will only be
triggered if
 1) the fallback option is on (it will be by default)
 2) the user is running mpl in an environment in which a user
interface already has a running mainloop
 3) the default backend is known to be incompatible. Eg, if the
default backend is PS, nothing will happen.
I think the proposed changes are reasonable.
JDH