Contour error

[alejogm0520]

Hi, I've been trying to use this plugin, however I find this error:

The contour plugin is disabled as it requires python modules numpy, matplotlib, and shapely which are not all installed.

I'm using:

• Qgis: 2.18 "Las palmas"
• Python: Python 2.7.13
• Matplotlib: 1.5.2rc2
• Numpy: 1.11.0
• Shapely: 1.5.17
• Fedora 24

Someone knows how to fix it ?

Thanks!!!!

-Alejo

[ccrook]

Hi @alejogm0520

This error is generated from the following python code.

mplAvailable=True
try:
    import numpy as np
    import matplotlib as mpl
    import matplotlib.pyplot as plt
    from matplotlib.mlab import griddata
    from shapely.geometry import MultiLineString, MultiPolygon
except:
    mplAvailable=False

If you open the python console from the Plugin menu in QGIS and type in each of the import lines one by one, then one of them should give an error. That will tell you which python library is not importing as expected.

[alejogm0520]

Hi @ccrook Thanks for the fast answer, but I'm afraid that all the libraries are fine, there is no error when import the libraries at the python console from QGis, and the error stilll happen. Thanks!

-Alejo

[ccrook]

@alejogm0520. Thanks for confirming this. I'm not sure how to proceed now though, as the error "contour plugin is disabled" only occurs if mplAvailable is False, and mplAvailable is only set by the code above. So if these imports do not result in an exception then the error should not be triggered.

Are you able to find and edit the contour.py file. If so then you could locate the code above and replace it with

...
except:
  raise
  mplAvailable=False

That way the contour plugin should fail to load and you should see the exception that caused the problem. Which would be useful to know in terms of fixing it.

[basilrabi]

it seems we have to install python-matplotlib-qt4. After installing, the issue seems fixed.

[jcpayne]

Can someone please explain how to install python-matplotlib-qt4, if that is indeed the problem?

[ccrook]

@jcpayne Before that it might be worth testing which import is failing. I suggest opening the python console and entering each of these lines in turn, and see which one fails. I'm not sure why matplotlib would require the qt4 component (especially as QGIS3 uses qt5). I suspect that this installation fixed some other missing component in matplotlib.

import numpy as np
import matplotlib as mpl
import matplotlib.pyplot as plt
from matplotlib.mlab import griddata
from shapely.geometry import MultiLineString, MultiPolygon

[ccrook]

This issue now closed - see #34