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Jae-Joon Lee wrote:
> Looking at the code, the "transparent" option set alphas of paches to
> 0, which I think is simply ignored in ps backend (which does not
> support alpha). I think it is better if the visibility of patches is
> set to False when the "transparent" option is set.

The ps backend does not support alpha in general, but it does use 
alpha=0 as a flag to not render.  The problem is that there is a single 
alpha for an artist with both line color and face color.  The artist 
alpha kwarg and attribute are at the root of much of the present 
alpha-mess in mpl.

> 
> Setting patch's (face) color to "none" work for me. If it does not
> work, please post a complete script.

I think this is what needs to be fixed in figure.py: the transparent 
option should be manipulating the patch facecolors, not the patch artist 
alpha value.

Eric

> 
> Regards,
> 
> -JJ
> 
> 
> 
> On Mon, Apr 26, 2010 at 2:38 AM, T J <tj...@gm...> wrote:
>> Not sure when this occurred, but I just updated to the latest SVN and
>> still see the issue:
>>   I am no longer able to save transparent figure---specifically, I
>> need no patch drawn for the figure and axis when saving to EPS.
>>
>>>>> savefig('test.eps', transparent=True)
>> The above should work, but it doesn't..  Explicitly setting the patch
>> colors to 'none' doesn't work either.
>>
>> Anyone else seeing this?
>>
>> ------------------------------------------------------------------------------
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Hi,

Believe it or not, the factor of 10000 was my only problem all the time.
Until you pointed it out I never noticed that it was missing in one of
the calls.


Thanks!
Niko


On 04/26/2010 03:26 PM, Jae-Joon Lee wrote:
> I think I'm lost.
> 
> 
>>  In other words: the colorbar created
>> by imshow should have the same values as the one created by contourf.
> 
> But, in your original post, your plotting two different image.
> with contourf, you're drawing "omega*10000", but with imshow, you're
> drawing "omega".
> Are you saying that these two should have same colorbar, although
> there is a factor 10000 difference?
> 
> And, as far as I know, colorbar shows values of the original input.
> 
> What is the min and max of omega, and what do you expect your colorbar show?
> If possible, please post a complete example so that others can test.
> 
> Regards,
> 
> -JJ
> 
> 
>>
>> I am not sure how I can use vmin and vmax to achieve that effect. The
>> scaling is done correctly, it's just that the colorbar should show the
>> original, and not the rescaled values.
>>
>> Thanks,
>> -Niko
>>
>>
>> I did not try vmin and vmax, because
>> On 04/26/2010 02:31 PM, Jae-Joon Lee wrote:
>>> Did you try to change vmin, vmax?
>>>
>>> http://matplotlib.sourceforge.net/api/pyplot_api.html#matplotlib.pyplot.imshow
>>>
>>> If this is not what you want, please describe more explicitly why the
>>> colorbar is wrong.
>>>
>>> Regards,
>>>
>>> -JJ
>>>
>>>
>>> On Mon, Apr 26, 2010 at 11:37 AM, Nikolaus Rath <Nik...@ra...> wrote:
>>>> The problem with imshow is, that it rescales the data so the
>>>> colorbar does not show the correct amplitudes (see
>>>> www.rath.org/imshow.png):
>>>>
>>>>    ctr = ax.imshow(omega, cmap=cm.YlOrRd, aspect='equal', interpolation='nearest',
>>>>                    origin='lower', extent=(-(N-1)/2, (N-1)/2, 0, M-1))
>>>>    fig.colorbar(ctr)
>>>>    ax.set_xlim(xmin= -(N - 1) / 2, xmax=(N - 1) / 2)
>>>>    ax.set_ylim(ymin=0, ymax=M - 1)
>>>>    fig.show()
>>>>
>>>> Is there a way to get the proper amplitudes into the colorbar?
>>
>>
>>   -Nikolaus
>>
>> --
>>  »Time flies like an arrow, fruit flies like a Banana.«
>>
>>  PGP fingerprint: 5B93 61F8 4EA2 E279 ABF6  02CF A9AD B7F8 AE4E 425C
>>


   -Nikolaus

-- 
 »Time flies like an arrow, fruit flies like a Banana.«

  PGP fingerprint: 5B93 61F8 4EA2 E279 ABF6  02CF A9AD B7F8 AE4E 425C

On Mon, Apr 26, 2010 at 12:01 PM, Jae-Joon Lee <lee...@gm...> wrote:
> Looking at the code, the "transparent" option set alphas of paches to
> 0, which I think is simply ignored in ps backend (which does not
> support alpha). I think it is better if the visibility of patches is
> set to False when the "transparent" option is set.
>

Or both.

> Setting patch's (face) color to "none" work for me. If it does not
> work, please post a complete script.
>

Attached. But I'm not doing anything fancy.  I've also attached the
EPS along with a TEX document.

I think I'm lost.


>  In other words: the colorbar created
> by imshow should have the same values as the one created by contourf.

But, in your original post, your plotting two different image.
with contourf, you're drawing "omega*10000", but with imshow, you're
drawing "omega".
Are you saying that these two should have same colorbar, although
there is a factor 10000 difference?

And, as far as I know, colorbar shows values of the original input.

What is the min and max of omega, and what do you expect your colorbar show?
If possible, please post a complete example so that others can test.

Regards,

-JJ


>
> I am not sure how I can use vmin and vmax to achieve that effect. The
> scaling is done correctly, it's just that the colorbar should show the
> original, and not the rescaled values.
>
> Thanks,
> -Niko
>
>
> I did not try vmin and vmax, because
> On 04/26/2010 02:31 PM, Jae-Joon Lee wrote:
>> Did you try to change vmin, vmax?
>>
>> http://matplotlib.sourceforge.net/api/pyplot_api.html#matplotlib.pyplot.imshow
>>
>> If this is not what you want, please describe more explicitly why the
>> colorbar is wrong.
>>
>> Regards,
>>
>> -JJ
>>
>>
>> On Mon, Apr 26, 2010 at 11:37 AM, Nikolaus Rath <Nik...@ra...> wrote:
>>> The problem with imshow is, that it rescales the data so the
>>> colorbar does not show the correct amplitudes (see
>>> www.rath.org/imshow.png):
>>>
>>>    ctr = ax.imshow(omega, cmap=cm.YlOrRd, aspect='equal', interpolation='nearest',
>>>                    origin='lower', extent=(-(N-1)/2, (N-1)/2, 0, M-1))
>>>    fig.colorbar(ctr)
>>>    ax.set_xlim(xmin= -(N - 1) / 2, xmax=(N - 1) / 2)
>>>    ax.set_ylim(ymin=0, ymax=M - 1)
>>>    fig.show()
>>>
>>> Is there a way to get the proper amplitudes into the colorbar?
>
>
>   -Nikolaus
>
> --
>  »Time flies like an arrow, fruit flies like a Banana.«
>
>  PGP fingerprint: 5B93 61F8 4EA2 E279 ABF6  02CF A9AD B7F8 AE4E 425C
>

Looking at the code, the "transparent" option set alphas of paches to
0, which I think is simply ignored in ps backend (which does not
support alpha). I think it is better if the visibility of patches is
set to False when the "transparent" option is set.

Setting patch's (face) color to "none" work for me. If it does not
work, please post a complete script.

Regards,

-JJ



On Mon, Apr 26, 2010 at 2:38 AM, T J <tj...@gm...> wrote:
> Not sure when this occurred, but I just updated to the latest SVN and
> still see the issue:
>   I am no longer able to save transparent figure---specifically, I
> need no patch drawn for the figure and axis when saving to EPS.
>
>>>> savefig('test.eps', transparent=True)
>
> The above should work, but it doesn't..  Explicitly setting the patch
> colors to 'none' doesn't work either.
>
> Anyone else seeing this?
>
> ------------------------------------------------------------------------------
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>

Hi,

I want the colorbar to show the real fourier amplitudes, not the
amplitudes after rescaling to 0..1. In other words: the colorbar created
by imshow should have the same values as the one created by contourf.

I am not sure how I can use vmin and vmax to achieve that effect. The
scaling is done correctly, it's just that the colorbar should show the
original, and not the rescaled values.

Thanks,
-Niko


I did not try vmin and vmax, because
On 04/26/2010 02:31 PM, Jae-Joon Lee wrote:
> Did you try to change vmin, vmax?
> 
> http://matplotlib.sourceforge.net/api/pyplot_api.html#matplotlib.pyplot.imshow
> 
> If this is not what you want, please describe more explicitly why the
> colorbar is wrong.
> 
> Regards,
> 
> -JJ
> 
> 
> On Mon, Apr 26, 2010 at 11:37 AM, Nikolaus Rath <Nik...@ra...> wrote:
>> The problem with imshow is, that it rescales the data so the
>> colorbar does not show the correct amplitudes (see
>> www.rath.org/imshow.png):
>>
>>    ctr = ax.imshow(omega, cmap=cm.YlOrRd, aspect='equal', interpolation='nearest',
>>                    origin='lower', extent=(-(N-1)/2, (N-1)/2, 0, M-1))
>>    fig.colorbar(ctr)
>>    ax.set_xlim(xmin= -(N - 1) / 2, xmax=(N - 1) / 2)
>>    ax.set_ylim(ymin=0, ymax=M - 1)
>>    fig.show()
>>
>> Is there a way to get the proper amplitudes into the colorbar?


   -Nikolaus

-- 
 »Time flies like an arrow, fruit flies like a Banana.«

  PGP fingerprint: 5B93 61F8 4EA2 E279 ABF6  02CF A9AD B7F8 AE4E 425C

Did you try to change vmin, vmax?

http://matplotlib.sourceforge.net/api/pyplot_api.html#matplotlib.pyplot.imshow

If this is not what you want, please describe more explicitly why the
colorbar is wrong.

Regards,

-JJ


On Mon, Apr 26, 2010 at 11:37 AM, Nikolaus Rath <Nik...@ra...> wrote:
> The problem with imshow is, that it rescales the data so the
> colorbar does not show the correct amplitudes (see
> www.rath.org/imshow.png):
>
>    ctr = ax.imshow(omega, cmap=cm.YlOrRd, aspect='equal', interpolation='nearest',
>                    origin='lower', extent=(-(N-1)/2, (N-1)/2, 0, M-1))
>    fig.colorbar(ctr)
>    ax.set_xlim(xmin= -(N - 1) / 2, xmax=(N - 1) / 2)
>    ax.set_ylim(ymin=0, ymax=M - 1)
>    fig.show()
>
> Is there a way to get the proper amplitudes into the colorbar?

On Fri, Apr 23, 2010 at 11:07 AM, Thomas Robitaille
<tho...@gm...> wrote:
> Hi,
>
> I'm having issues with translucent patches. The following code
>
> import matplotlib
> matplotlib.use('Agg')
> import matplotlib.pyplot as mpl
> from matplotlib.patches import Circle
>
> fig = mpl.figure()
> ax = fig.add_subplot(111)
> c = Circle((0.25,0.5), radius=0.2, facecolor='none', edgecolor='green', alpha=0.2)
> ax.add_patch(c)
> c = Circle((0.75,0.5), radius=0.2, facecolor='blue', edgecolor='green', alpha=0.2)
> ax.add_patch(c)
> fig.savefig('test_alpha.png')
>
> Produces a plot where the two circles have different borders - the left circle has a border with alpha=1.0 and the right circle has a border with alpha=0.2. Should I submit this as a bug report?
>

This is kind of a known bug.

http://old.nabble.com/patches-have-incorrect-alpha-values-td22667217.html#a22667217

But, please go ahead and file a bug report.

Fixing this requires some changes in backend api, and I'm not sure if
this will be fixed soon.

Regards,

-JJ

Hi
In an embedded application, I want to have a number of FigureCanvas s inside
a scrolled window. But the FigureCanvas s always resize to fit inside my
main window. I've tried intercepting resize requests but nothing seems to
work. Any ideas?


Mathew

Peter Buschman-2 wrote:
> 
> 
> I ended up finding a solution to this by using a FixedLocator and 
> manually setting each of the tick
> positions for both major and minor grids without overlap.
> 
> I'm not sure if this is the recommended way to do this, but hey, it worked
> ;-)
> 
>      for tick in range(seconds+1)[1:]:
>          if tick % major_multiple == 0:
>              xmajorticks.append(tick)
>          elif tick % minor_multiple == 0:
>              xminorticks.append(tick)
> 
>      ax.xaxis.set_major_locator(FixedLocator(xmajorticks))
>      ax.xaxis.set_minor_locator(FixedLocator(xminorticks))
> 
> 

Hi there,
I know this is an old post, but I'm also trying to do something similar, but
using different linestyles for the major and minor grids.

Has anyone figured out code that's more efficient than this? It seems that
this can slow down my application's data "load time". Also, since I'm using
the zoom widget, I'm not certain if this will work if the tick markers
change If I change my x limits... Any thoughts?


-----
Krishna Adrianto Pribadi
Test Engineer
Harley-Davidson Motor Co.
Talladega Test Facility
Vehicle Test Stands
-- 
View this message in context: http://old.nabble.com/Setting-color-of-both-major-and-minor-gridlines--tp9475256p28367421.html
Sent from the matplotlib - users mailing list archive at Nabble.com.

Hello,

I have 2d array with fourier amplitudes that I would like to plot. I
found two options: contourf and imshow. This is my code:

    omega = np.fft.rfftn(b_field, axes=(1, 0))
    omega = np.abs(np.fft.fftshift(omega, axes=(1,)))
    fig = plt.figure()
    ax = fig.add_subplot(111)
    M = omega.shape[0]
    N = omega.shape[1]
    ax.set_title('Spectrum')
    ax.set_ylabel(r'Poloidal Mode Number m')
    ax.set_xlabel(r'Toroidal Mode Number n')
    ax.grid(True)

    # Get rid of normalization
    omega /= np.prod(omega.shape)
    
The problem with contourf is that I can't seem to stop it from
strongly interpolating the data, which obscures the discrete nature:
(see www.rath.org/contourf.png)

    ctr = ax.contourf(np.arange(-N / 2, N / 2),
                      np.arange(0, M),
                      omega * 10000, 100, cmap=cm.YlOrRd, interpolation='nearest')
    fig.colorbar(ctr)
    ax.set_xlim(xmin= -(N - 1) / 2, xmax=(N - 1) / 2)
    ax.set_ylim(ymin=0, ymax=M - 1)
    fig.show()

Apparently contourf does not accept the interpolation='nearest' option.
Is there a way to make it stop interpolating?

The problem with imshow is, that it rescales the data so the
colorbar does not show the correct amplitudes (see
www.rath.org/imshow.png):

    ctr = ax.imshow(omega, cmap=cm.YlOrRd, aspect='equal', interpolation='nearest',
                    origin='lower', extent=(-(N-1)/2, (N-1)/2, 0, M-1))
    fig.colorbar(ctr)
    ax.set_xlim(xmin= -(N - 1) / 2, xmax=(N - 1) / 2)
    ax.set_ylim(ymin=0, ymax=M - 1)
    fig.show()

Is there a way to get the proper amplitudes into the colorbar?


Thanks!


   -Nikolaus

-- 
 »Time flies like an arrow, fruit flies like a Banana.«

  PGP fingerprint: 5B93 61F8 4EA2 E279 ABF6  02CF A9AD B7F8 AE4E 425C

Not sure when this occurred, but I just updated to the latest SVN and
still see the issue:
   I am no longer able to save transparent figure---specifically, I
need no patch drawn for the figure and axis when saving to EPS.

>>> savefig('test.eps', transparent=True)

The above should work, but it doesn't..  Explicitly setting the patch
colors to 'none' doesn't work either.

Anyone else seeing this?