[Matplotlib-devel] Possible bug in matplotlib versions 1.4 and higher with basemap arcgisimage imagery

[Michael Droettboom]

Can you provide a standalone example to reproduce, or fire up the debugger
and let me know that the value of "basemap_url" is on line 4270 of
basemap/__init__.py?  Were that to point to somewhere that fails, one would
expect this error.  (Though in the case of 1.5.1 something additionally
funky is going on, I'm not necessarily surprised by the result with 1.4.3
without additional information).

Mike

On Mon, Jan 25, 2016 at 10:53 AM, Benjamin Root <ben.v.root at gmail.com>
wrote:

> Yes, I recently noticed this, too. CC-ing Mike Droettboom, I think this is
> caused by our recent changes to _image.cpp to add error-checking.
>
> Ben Root
>
> On Fri, Jan 22, 2016 at 3:43 AM, Mike Tercek via Matplotlib-devel <
> matplotlib-devel at python.org> wrote:
>
>> When I make a map with the basemap and try to insert a background image
>> from acrgis servers, the following code works ok if I have maplotlib
>> version 1.3.1 installed:
>>
>> m =
>> Basemap(llcrnrlon=ll_lon,llcrnrlat=ll_lat,urcrnrlon=ur_lon,urcrnrlat=ur_lat,epsg=3857,lat_0=latz,lon_0=lonz,
>> fix_aspect = False)
>> m.arcgisimage(service='ESRI_Imagery_World_2D', xpixels = 2000, verbose=
>> False, dpi = 80)
>>
>> However, if I have matplotlib version 1.4.3 installed I get the following
>> error:
>>
>> Python 3.4.3 (default, Oct 14 2015, 20:28:29)
>> [GCC 4.8.4] on linux
>> Type "help", "copyright", "credits" or "license" for more information.
>> >>> runfile('/media/mt/7670100C700FD1B3/vegviz/contain/xv.py',
>> wdir=r'/media/mt/7670100C700FD1B3/vegviz/contain')
>> Content-Type: text/html
>>
>> Traceback (most recent call last):
>>   File "<stdin>", line 1, in <module>
>>   File
>> "/usr/local/lib/python3.4/dist-packages/spyderlib/widgets/externalshell/sitecustomize.py",
>> line 680, in runfile
>>     execfile(filename, namespace)
>>   File
>> "/usr/local/lib/python3.4/dist-packages/spyderlib/widgets/externalshell/sitecustomize.py",
>> line 85, in execfile
>>     exec(compile(open(filename, 'rb').read(), filename, 'exec'),
>> namespace)
>>   File "/media/mt/7670100C700FD1B3/vegviz/contain/xv.py", line 401, in
>> <module>
>>     m,fig =
>> make_base_map(title,frame_bound,park_bound,inset,inset_location,inset_alignment,ll_lon,ll_lat,ur_lon,ur_lat,latz,lonz,True)
>>   File "/media/mt/7670100C700FD1B3/vegviz/contain/xv.py", line 110, in
>> make_base_map
>>     m.arcgisimage(service='ESRI_Imagery_World_2D', xpixels = 2000,
>> verbose= False, dpi = 80)
>>   File
>> "/usr/local/lib/python3.4/dist-packages/mpl_toolkits/basemap/__init__.py",
>> line 4270, in arcgisimage
>>     return
>> self.imshow(imread(urllib.request.urlopen(basemap_url)),origin='upper')
>>   File "/usr/local/lib/python3.4/dist-packages/matplotlib/image.py", line
>> 1270, in imread
>>     return handler(fname)
>> RuntimeError: _image_module::readpng: file not recognized as a PNG file
>>
>> And if I install matplotlib 1.5.1, I get this error:
>>
>> Python 3.4.3 (default, Oct 14 2015, 20:28:29)
>> [GCC 4.8.4] on linux
>> Type "help", "copyright", "credits" or "license" for more information.
>> >>> runfile('/media/mt/7670100C700FD1B3/vegviz/contain/xv.py',
>> wdir=r'/media/mt/7670100C700FD1B3/vegviz/contain')
>> Content-Type: text/html
>>
>> Traceback (most recent call last):
>>   File "<stdin>", line 1, in <module>
>>   File
>> "/usr/local/lib/python3.4/dist-packages/spyderlib/widgets/externalshell/sitecustomize.py",
>> line 680, in runfile
>>     execfile(filename, namespace)
>>   File
>> "/usr/local/lib/python3.4/dist-packages/spyderlib/widgets/externalshell/sitecustomize.py",
>> line 85, in execfile
>>     exec(compile(open(filename, 'rb').read(), filename, 'exec'),
>> namespace)
>>   File "/media/mt/7670100C700FD1B3/vegviz/contain/xv.py", line 401, in
>> <module>
>>     m,fig =
>> make_base_map(title,frame_bound,park_bound,inset,inset_location,inset_alignment,ll_lon,ll_lat,ur_lon,ur_lat,latz,lonz,True)
>>   File "/media/mt/7670100C700FD1B3/vegviz/contain/xv.py", line 110, in
>> make_base_map
>>     m.arcgisimage(service='ESRI_Imagery_World_2D', xpixels = 2000,
>> verbose= False, dpi = 80)
>>   File
>> "/usr/local/lib/python3.4/dist-packages/mpl_toolkits/basemap/__init__.py",
>> line 4270, in arcgisimage
>>     return
>> self.imshow(imread(urllib.request.urlopen(basemap_url)),origin='upper')
>>   File "/usr/local/lib/python3.4/dist-packages/matplotlib/image.py", line
>> 1326, in imread
>>     return handler(fname)
>> SystemError: error return without exception set
>>
>>
>>
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Matplotlib-devel at python.org
>> https://mail.python.org/mailman/listinfo/matplotlib-devel
>>
>>
>


-- 
Michael Droettboom
Continuum Analytics
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/matplotlib-devel/attachments/20160125/f6dc665a/attachment-0001.html>