`plot` does not show cell scalars by default when only cell scalars exist about pyvista HOT 6 CLOSED

This looks suspicious to me as well. It seems like it is a bug in higher level design to me since this function takes in an ndarray rather than a str, so it cannot figure out whether the data is originally point or cell data in this ambiguous case. I suspect we have to pass in a definitive use_points or similar and have logic in the calling function or a separate helper function to decide.

This bit of logic feels suspect to me:

pyvista/pyvista/plotting/mapper.py

Lines 455 to 460 in 7636dc7

	if scalars.shape[0] == self.dataset.n_points and scalars.shape[0] == self.dataset.n_cells:
	use_points = preference == 'point'
	use_cells = not use_points
	else:
	use_points = scalars.shape[0] == self.dataset.n_points
	use_cells = scalars.shape[0] == self.dataset.n_cells

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This part of the code is executed before the _configure_scalar_mode in the mapper gets called in the example given in the issue. One potential solution might be to reset the preference in this part of the code based on the scalar array found. I'm also wary about the comment in this part of the code, so that is another avenue to explore

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I think the crux of this is that c.n_points == c.n_cells which is somewhat of an edge case.

It looks like there is a genuine bug here. After plotting, if we repr the mesh in a Jupyter cell it looks like something in the plotting routine got confused and set a new point_data array because the length matched (which is incorect):

As an aside, this feels related to #1897

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This bit of logic feels suspect to me:

I think preference defaults to 'point' and this bit of logic then thinks the scalars should be on the points... some further digging is needed

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"This should be refactored by 0.36.0"

🤣

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One potential solution might be to reset the preference in this part of the code based on the scalar array found.

I think this could work! Nice find!

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