Re: [Matplotlib-users] imlim in ax.imshow

[Damon M. <dam...@gm...>]

On Tue, Oct 2, 2012 at 8:07 PM, K.-Michael Aye <kmi...@gm...> wrote:
>
> On Oct 2, 2012, at 12:06 PM, Damon McDougall <dam...@gm...> wrote:
>
>> On Tue, Oct 2, 2012 at 8:00 PM, K.-Michael Aye <kmi...@gm...> wrote:
>>>
>>> On Oct 2, 2012, at 11:09 AM, Damon McDougall <dam...@gm...> wrote:
>>>
>>>> On Tue, Oct 2, 2012 at 5:51 PM, K.-Michael Aye <kmi...@gm...> wrote:
>>>>>
>>>>>
>>>>> On Oct 2, 2012, at 6:33 AM, Damon McDougall <dam...@gm...> wrote:
>>>>>
>>>>>> On Tue, Oct 2, 2012 at 2:19 PM, Benjamin Root <ben...@ou...> wrote:
>>>>>>>
>>>>>>>
>>>>>>> On Mon, Oct 1, 2012 at 7:20 PM, Michael Aye <kmi...@gm...> wrote:
>>>>>>>>
>>>>>>>> Hi!
>>>>>>>>
>>>>>>>> I see that the function ax.imshow takes the parameter 'imlim' but in
>>>>>>>> the source (status: EPD 7.3-2) it is not being used?
>>>>>>>> So what is it for?
>>>>>>>>
>>>>>>>> Best regards,
>>>>>>>> Michael
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>> Confirmed.  I don't see imlim anywhere except in the imshow() signature.  I
>>>>>>> have no recollection of this parameter, so it might be from before my time.
>>>>>>>
>>>>>>> Ben Root
>>>>>>
>>>>>> Is there some functionality you were looking for or were you just
>>>>>> exploring the codebase?
>>>>>>
>>>>> How nice of you to ask! ;)
>>>>> Indeed: I had the case that image arrays inside an ImageGrid where shown with some white overhead area around, e.g. for an image of 100 pixels on the x-axis, the imshow resulted in an x-axis that went from -10 to 110. I was looking for a simple way to suppress that behavior and let imshow instead use the exact image extent. I believe that the plot command has such a flag, hasn't it? (I.e. to use the exact xdata range and not try to beautify the plot?
>>>>>
>>>>> Michael
>>>>>
>>>>>
>>>>>> --
>>>>>> Damon McDougall
>>>>>> http://www.damon-is-a-geek.com
>>>>>> B2.39
>>>>>> Mathematics Institute
>>>>>> University of Warwick
>>>>>> Coventry
>>>>>> West Midlands
>>>>>> CV4 7AL
>>>>>> United Kingdom
>>>>
>>>> Is the 'extent' keyword what you're looking for?
>>>>
>>>
>>> No, because it needs detail. I was looking for a boolean switch that basically says: Respect the data, not beauty.
>>
>> I don't understand what you mean by 'beauty'. If your image is 100
>> pixels wide and 50 pixels tall, what is it about extent=[0,100,0,50]
>> that doesn't do what you want?
>>
> As I wrote, that's not what is happening. I get extent=[-10,110,0,50].
>
>
>> --
>> Damon McDougall
>> http://www.damon-is-a-geek.com
>> B2.39
>> Mathematics Institute
>> University of Warwick
>> Coventry
>> West Midlands
>> CV4 7AL
>> United Kingdom
>

The following script works for me:

import numpy as np
import matplotlib.pyplot as plt

image = np.random.random((100,50))

fig = plt.figure()
ax = fig.add_subplot(1, 1, 1)
ax.imshow(image, extent=[0,100,0,50])
plt.show()


-- 
Damon McDougall
http://www.damon-is-a-geek.com
B2.39
Mathematics Institute
University of Warwick
Coventry
West Midlands
CV4 7AL
United Kingdom