ValueError in Visualizing Results On Provided Example Files After Quickstart

[ekschuman]

Review: openjournals/joss-reviews#2123

Working through the "Product generation" and "Visualizing results" sections of the API Reference in the documentation, I ran into a few errors when trying to run the cloudnetpy.plotting generate_figure function given as examples. This happened on the following 3 commands:

generate_figure('iwc_file.nc', ['iwc', 'iwc_error', 'iwc_retrieval_status'])
generate_figure('lwc_file.nc', ['lwc', 'lwc_error', 'lwc_retrieval_status'], max_y=4)
generate_figure('classification_file.nc', ['target_classification', 'detection_status'])

I downloaded the example files provided by the Quickstart documentation, and followed through all of the quickstart steps to generate these files. I then wen through all of the steps in "Product generation" in the API reference without issue, until I got to the "Visualizing results" section.

Running the figure generation resulted in a few variants of the same error, but the plots still seemed to be generated. (note that the examples using the categorize_file and the drizzle_file did not throw these errors):

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-17-66eb155af8df> in <module>
----> 1 generate_figure('iwc.nc', ['iwc', 'iwc_error', 'iwc_retrieval_status'])

~/anaconda/envs/cloudnet/lib/python3.8/site-packages/cloudnetpy/plotting/plotting.py in generate_figure(nc_file, field_names, show, save_path, max_y, dpi, image_name, sub_title, title)
     57 
     58         elif plot_type == 'segment':
---> 59             _plot_segment_data(ax, field, name, ax_value)
     60 
     61         else:

~/anaconda/envs/cloudnet/lib/python3.8/site-packages/cloudnetpy/plotting/plotting.py in _plot_segment_data(ax, data, name, axes)
    226     colorbar = _init_colorbar(pl, ax)
    227     colorbar.set_ticks(np.arange(len(clabel) + 1))
--> 228     colorbar.ax.set_yticklabels(clabel, fontsize=13)
    229 
    230 

~/anaconda/envs/cloudnet/lib/python3.8/site-packages/matplotlib/axes/_base.py in wrapper(self, *args, **kwargs)
     61 
     62         def wrapper(self, *args, **kwargs):
---> 63             return get_method(self)(*args, **kwargs)
     64 
     65         wrapper.__module__ = owner.__module__

~/anaconda/envs/cloudnet/lib/python3.8/site-packages/matplotlib/cbook/deprecation.py in wrapper(*args, **kwargs)
    449                 "parameter will become keyword-only %(removal)s.",
    450                 name=name, obj_type=f"parameter of {func.__name__}()")
--> 451         return func(*args, **kwargs)
    452 
    453     return wrapper

~/anaconda/envs/cloudnet/lib/python3.8/site-packages/matplotlib/axis.py in _set_ticklabels(self, labels, fontdict, minor, **kwargs)
   1791         if fontdict is not None:
   1792             kwargs.update(fontdict)
-> 1793         return self.set_ticklabels(labels, minor=minor, **kwargs)
   1794 
   1795     @cbook._make_keyword_only("3.2", "minor")

~/anaconda/envs/cloudnet/lib/python3.8/site-packages/matplotlib/axis.py in set_ticklabels(self, ticklabels, minor, **kwargs)
   1712             # remove all tick labels, so only error for > 0 ticklabels
   1713             if len(locator.locs) != len(ticklabels) and len(ticklabels) != 0:
-> 1714                 raise ValueError(
   1715                     "The number of FixedLocator locations"
   1716                     f" ({len(locator.locs)}), usually from a call to"

ValueError: The number of FixedLocator locations (8), usually from a call to set_ticks, does not match the number of ticklabels (7).

[tukiains]

This was caused by a bug in the colorbar ticks. Thanks for spotting! It is fixed in 22fc3d4, included in https://github.com/actris-cloudnet/cloudnetpy/releases/tag/v1.2.2.