matplotlib-devel Mailing List for matplotlib

Ryan May wrote:
> John Hunter wrote:
> 
>> Ryan May has been doing all the heavy lifting with respect to PSD and
>> specgram, so I am going to turf this to him :-) It may be that the
>> bug filer's problems are resolved in the recent changes in 98.5.2, but
>> Ryan should confirm
>>
>> On Fri, Jan 9, 2009 at 2:45 PM, Dave Peterson <dpe...@en...> wrote:
>> 
>>> Hi John,
>>>
>>> Sorry for sending this directly, but I'm still waiting for my matplotlib
>>> devel mailing subscription to go through....
>>>
>>> We've just had an EPD user submit a patch for matplotlib to 'fix' a problem
>>> they were seeing with the PSD function. Is this a known issue or something
>>> that you'd be interested in including in future versions of matplotlib? Or
>>> is it something that you disagree is 'right'?
>>>
>>> https://svn.enthought.com/epd/ticket/581
>>>
>>> I'd like to know to do the right thing with the matplotlib we include in
>>> EPD. :-)
>>> 
>
> Specgram specifically handles the case of moving frequencies to -Fs/2 to Fs/2,
> instead of 0 to Fs. It was this way before I did any of my changes and I just
> left it as it was. Psd returns frequencies 0 to Fs for Matlab compatibility (I
> think anyways, John?). Personally, I'd also prefer to have -Fs/2 to Fs/2
> returned as well, so I don't have to do it in my own code. However, I'm also
> loath to add yet another flag to toggle Matlab compatibility.
>
> As far as the patch goes, it looks fine. It won't work as is with the
> refactoring I've already done in SVN, but it wouldn't be hard to implement the
> changes, if we decide to go that way.
>
> Maybe it's time to refactor here to get routine(s) that operate how we want (IMO
> more sanely than Matlab), and we provide wrappers that give Matlab-like behavior.
> Maybe we can also get these sane routines upstream into Scipy. At that point,
> however, I'm not sure what to do about the plotting functions, since there's a
> variety of behavior.
>
> Thoughts?
>
> Ryan
> 
Hi Guys,
I'm not sure what's going on with my subscription request e-mail. So 
I'll reply-all and see what happens...
I can't speak too strongly about what should be there but I certainly 
like Ryan's idea of getting more sane behavior and simultaneously 
providing a wrapper / second API entry point to get the Matlab 
compatible behavior. 
As far as EPD goes, since this didn't result in a "yes, we'll apply it" 
response, we'll hold off on applying this patch to the matplotlib build 
we ship inside EPD until you guys figure out which way you're headed. 
It clearly seems wrong to have different, non-bug, behavior between your 
releases and EPD.
-- Dave

There appears to be a bug in the macosx backend. When I plot large 
numbers with small variations in the value, the numbers seem to be 
coarsely rounded off. This bug doesn't appear with other backends (I 
tried WxAgg and TkAgg). Below is a simple script showing the problem 
and the resulting plot on the macosx backend.
Thanks,
-Tony
Mac OS X 10.5.6
Matplotlib svn r6779
#~~~~~~~~
import numpy as np
import matplotlib.pyplot as plt
x = np.linspace(0, 1)
plt.plot(x, x + 1e6)
plt.show()

On Mon, Jan 12, 2009 at 3:29 AM, T J <tj...@gm...> wrote:
> It looks like mincnt is used only when C is not None. For the default
> histogram method, I've found it useful to be able to turn off cells
> with fewer then *mincnt* points. Attached is a diff which implements
> this. Also, should *marginals* be True by default? It seems that
> hexbin is an alternative to scatter and since scatter doesn't have it,
> then hexbin should not have it either.
Thanks for the mincnt patch, I've applied it to svn head and made
marginals False -- I *thought* I made it False when adding it, so this
was just a screwup.
JDH

It looks like mincnt is used only when C is not None. For the default
histogram method, I've found it useful to be able to turn off cells
with fewer then *mincnt* points. Attached is a diff which implements
this. Also, should *marginals* be True by default? It seems that
hexbin is an alternative to scatter and since scatter doesn't have it,
then hexbin should not have it either.