Masked nan

I have a problem that arose when I tried to run the gridding irregularly
spaced data demo on the wiki
http://www.scipy.org/Cookbook/Matplotlib/Gridding_irregularly_spaced_data

When I run the attached script, which sets one value of an array to nan, masks the array where there are nan, and tries to plot it using contour(), I get the following errors:

/usr/lib/python2.4/site-packages/numpy/core/ma.py:604: UserWarning: Cannot automatically convert masked array to numeric because data
     is masked in one or more locations.
   warnings.warn("Cannot automatically convert masked array to "\
Traceback (most recent call last):
   File "masked_nan.py", line 18, in ?
     contour(x, y, z)
   File "/usr/lib/python2.4/site-packages/matplotlib/pylab.py", line 1754, in contour
     ret = gca().contour(*args, **kwargs)
   File "/usr/lib/python2.4/site-packages/matplotlib/axes.py", line 4092, in contour
     return ContourSet(self, *args, **kwargs)
   File "/usr/lib/python2.4/site-packages/matplotlib/contour.py", line 429, in __init__
     x, y, z = self._contour_args(*args) # also sets self.levels,
   File "/usr/lib/python2.4/site-packages/matplotlib/contour.py", line 614, in _contour_args
     lev = self._autolev(z, 7)
   File "/usr/lib/python2.4/site-packages/matplotlib/contour.py", line 517, in _autolev
     zmargin = (zmax - zmin) * 0.001 # so z < (zmax + zmargin)
TypeError: unsupported operand type(s) for -: 'str' and 'str'

I am using
>>> numpy.__version__
'1.0'
>>> matplotlib.__version__
'0.87.7'

Is there a way to use contour() and plot arrays whose elements may be nan?

Thanks,
Paul

masked_nan.py (241 Bytes)

Paul Novak wrote:

I have a problem that arose when I tried to run the gridding irregularly
spaced data demo on the wiki
http://www.scipy.org/Cookbook/Matplotlib/Gridding_irregularly_spaced_data

When I run the attached script, which sets one value of an array to nan, masks the array where there are nan, and tries to plot it using contour(), I get the following errors:

/usr/lib/python2.4/site-packages/numpy/core/ma.py:604: UserWarning: Cannot automatically convert masked array to numeric because data
    is masked in one or more locations.
  warnings.warn("Cannot automatically convert masked array to "\
Traceback (most recent call last):
  File "masked_nan.py", line 18, in ?
    contour(x, y, z)
  File "/usr/lib/python2.4/site-packages/matplotlib/pylab.py", line 1754, in contour
    ret = gca().contour(*args, **kwargs)
  File "/usr/lib/python2.4/site-packages/matplotlib/axes.py", line 4092, in contour
    return ContourSet(self, *args, **kwargs)
  File "/usr/lib/python2.4/site-packages/matplotlib/contour.py", line 429, in __init__
    x, y, z = self._contour_args(*args) # also sets self.levels,
  File "/usr/lib/python2.4/site-packages/matplotlib/contour.py", line 614, in _contour_args
    lev = self._autolev(z, 7)
  File "/usr/lib/python2.4/site-packages/matplotlib/contour.py", line 517, in _autolev
    zmargin = (zmax - zmin) * 0.001 # so z < (zmax + zmargin)
TypeError: unsupported operand type(s) for -: 'str' and 'str'

I am using
>>> numpy.__version__
'1.0'
>>> matplotlib.__version__
'0.87.7'

Is there a way to use contour() and plot arrays whose elements may be nan?

Thanks,
Paul

Paul: Your test script works for me (numpy 1.0, matplotlib 0.87.7, python2.5 on macos x).

-Jeff

···

--
Jeffrey S. Whitaker Phone : (303)497-6313
NOAA/OAR/CDC R/PSD1 FAX : (303)497-6449
325 Broadway Boulder, CO, USA 80305-3328

It worked fine for me too. Do you happen to have numerix : Numeric in your
matplotlibrc file?

Darren

···

On Thursday 21 December 2006 13:43, Jeff Whitaker wrote:

Paul Novak wrote:
> I have a problem that arose when I tried to run the gridding irregularly
> spaced data demo on the wiki
> http://www.scipy.org/Cookbook/Matplotlib/Gridding_irregularly_spaced_data
>
> When I run the attached script, which sets one value of an array to
> nan, masks the array where there are nan, and tries to plot it using
> contour(), I get the following errors:
>
> /usr/lib/python2.4/site-packages/numpy/core/ma.py:604: UserWarning:
> Cannot automatically convert masked array to numeric because data
> is masked in one or more locations.
> warnings.warn("Cannot automatically convert masked array to "\
> Traceback (most recent call last):
> File "masked_nan.py", line 18, in ?
> contour(x, y, z)
> File "/usr/lib/python2.4/site-packages/matplotlib/pylab.py", line
> 1754, in contour
> ret = gca().contour(*args, **kwargs)
> File "/usr/lib/python2.4/site-packages/matplotlib/axes.py", line
> 4092, in contour
> return ContourSet(self, *args, **kwargs)
> File "/usr/lib/python2.4/site-packages/matplotlib/contour.py", line
> 429, in __init__
> x, y, z = self._contour_args(*args) # also sets self.levels,
> File "/usr/lib/python2.4/site-packages/matplotlib/contour.py", line
> 614, in _contour_args
> lev = self._autolev(z, 7)
> File "/usr/lib/python2.4/site-packages/matplotlib/contour.py", line
> 517, in _autolev
> zmargin = (zmax - zmin) * 0.001 # so z < (zmax + zmargin)
> TypeError: unsupported operand type(s) for -: 'str' and 'str'
>
> I am using
>
> >>> numpy.__version__
>
> '1.0'
>
> >>> matplotlib.__version__
>
> '0.87.7'
>
> Is there a way to use contour() and plot arrays whose elements may be
> nan?
>
> Thanks,
> Paul

Paul: Your test script works for me (numpy 1.0, matplotlib 0.87.7,
python2.5 on macos x).

Adding the line numeric: numpy to my matplotlibrc file fixed the problem.

Thanks,
Paul

Darren Dale wrote:

···

On Thursday 21 December 2006 13:43, Jeff Whitaker wrote:

Paul Novak wrote:

I have a problem that arose when I tried to run the gridding irregularly
spaced data demo on the wiki
http://www.scipy.org/Cookbook/Matplotlib/Gridding_irregularly_spaced_data

When I run the attached script, which sets one value of an array to
nan, masks the array where there are nan, and tries to plot it using
contour(), I get the following errors:

/usr/lib/python2.4/site-packages/numpy/core/ma.py:604: UserWarning:
Cannot automatically convert masked array to numeric because data
    is masked in one or more locations.
  warnings.warn("Cannot automatically convert masked array to "\
Traceback (most recent call last):
  File "masked_nan.py", line 18, in ?
    contour(x, y, z)
  File "/usr/lib/python2.4/site-packages/matplotlib/pylab.py", line
1754, in contour
    ret = gca().contour(*args, **kwargs)
  File "/usr/lib/python2.4/site-packages/matplotlib/axes.py", line
4092, in contour
    return ContourSet(self, *args, **kwargs)
  File "/usr/lib/python2.4/site-packages/matplotlib/contour.py", line
429, in __init__
    x, y, z = self._contour_args(*args) # also sets self.levels,
  File "/usr/lib/python2.4/site-packages/matplotlib/contour.py", line
614, in _contour_args
    lev = self._autolev(z, 7)
  File "/usr/lib/python2.4/site-packages/matplotlib/contour.py", line
517, in _autolev
    zmargin = (zmax - zmin) * 0.001 # so z < (zmax + zmargin)
TypeError: unsupported operand type(s) for -: 'str' and 'str'

I am using

numpy.__version__

'1.0'

matplotlib.__version__

'0.87.7'

Is there a way to use contour() and plot arrays whose elements may be
nan?

Thanks,
Paul

Paul: Your test script works for me (numpy 1.0, matplotlib 0.87.7,
python2.5 on macos x).

It worked fine for me too. Do you happen to have numerix : Numeric in your matplotlibrc file?

Darren

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