Re: [Matplotlib-users] Affine2D on scatter

[Derek T. <der...@gm...>]

I've been seeing some discrepancy between display and saved figures.  See
attached.  One is the result of the save, the other is the screen capture
of the display.  I'm using 1.2.0 on a mac.


On Thu, Apr 4, 2013 at 9:46 AM, Derek Thomas <der...@gm...> wrote:

> I get a different result.
>
>
> On Thu, Apr 4, 2013 at 9:25 AM, Phil Elson <pel...@gm...> wrote:
>
>> Hi Derek,
>>
>> What are we looking at here?
>>
>> The following code:
>>
>> import matplotlib.pyplot as plt
>> import matplotlib.transforms as mtrans
>> import numpy as np
>>
>> plt.figure()
>> ax = plt.subplot(111)
>> base_trans = ax.transData
>> mtx = np.array([[1,1,0],
>>                 [0,1,0],
>>                 [0,0,1]])
>> tr = mtrans.Affine2D(matrix=mtx) + base_trans
>>
>> plt.plot([1,2,3], [1,2,3], 'gray', transform=tr)
>> plt.scatter([1,2,3], [1,2,3], c='k', marker='D', transform=tr)
>> plt.show()
>>
>> produces the following plot on v1.2.0:
>> [image: Inline images 1]
>> Is this unexpected or are you getting a different result to me?
>>
>> Regards,
>>
>>
>>
>> On 4 April 2013 17:06, Derek Thomas <der...@gm...> wrote:
>>
>>> I posted a related question on stackoverflow
>>> (
>>> http://stackoverflow.com/questions/15815862/apply-affine-transform-to-quiver-in-python-matplotlib
>>> )
>>> but I've produced a simple enough example with strange results that I
>>> think it merits attention here.  I'm trying to apply affine transforms
>>> to quiver and scatter plots.  In all cases that I've considered, the
>>> scatter and quiver plots transform opposite the regular plot.  Here's
>>> a minimal case:
>>>
>>> import matplotlib as mpl
>>> from pylab import figure, subplot, plot, scatter, show, axis
>>>
>>> figure()
>>> ax = subplot(111)
>>> base_trans = ax.transData
>>> tr =  mpl.transforms.Affine2D(matrix =
>>> array([[1,1,0],[0,1,0],[0,0,1]])) + base_trans
>>>
>>>
>>> plot( [1,2,3], [1,2,3], 'k.', transform = tr )
>>> scatter( [1,2,3], [1,2,3], c = 'k', marker = 'D', transform = tr )
>>> axis([0,7,0,7])
>>> show()
>>>
>>> Thanks,
>>>
>>> Derek
>>>
>>>
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>>
>>
>