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titusjan / argos

Argos: a data viewer that can read HDF5, NetCDF4, and other file formats.
GNU General Public License v3.0
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Image plot crosshair fails on NetCDF scalars set to fill value. #16

Closed titusjan closed 3 years ago

titusjan commented 3 years ago

When cross hair plots are enabled in the Image Plot inspector, and the user hovers above plot, and the selected item is a NetCDF scalar set to the fill value, the application exits with the following error:

Traceback (most recent call last):
  File "C:\Users\kenter\Documents\src\argos\argos\inspector\pgplugins\imageplot2d.py", line 587, in mouseMoved
    rowData = replaceMaskedValueWithFloat(rowData, np.isinf(rowData),
  File "C:\Users\kenter\Documents\src\argos\argos\utils\masks.py", line 252, in replaceMaskedValueWithFloat
    return replaceMaskedValue(data, mask, replacementValue, copyOnReplace=copyOnReplace)
  File "C:\Users\kenter\Documents\src\argos\argos\utils\masks.py", line 231, in replaceMaskedValue
    result[mask] = replacementValue
ValueError: assignment destination is read-only

This can be reproduced with the scalars.nc/masked_scalar item that can be generated by create_test_data.py

titusjan commented 3 years ago

The problem was that, apparently, ma.copy doesn't copy all the data. After copying the OWNDATA and WRITEABLE flags where still False.

Starting from Numpy 1.19.0, np.copy(..., subok=True) can be used to copy masked arrays as well. This fixes the issue.