Ability to plot embeddings that NaN values

In working with [e-mail] to remix his neuronal AD dataset for Corpora, we came upon the issue of visualizing subcluster embeddings that only have coordinate values for a subpopulation of cells. The solution we would like is to fill the other cell coordinates with NaNs and cellxgene would plot only the cells with numerical coordinates for each embedding. Currently, cellxgene shows a blank plot if there are any np.nan or np.inf in the embedding.

Previous issue identifying the “bug”: #1118

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Update: cellxgene will now accept embeddings containing a NaN value. +/- Inf continue to be rejected. This issue is left open as we are still working out how to improve the UX experience for embeddings with NaN values.

[mattcai]

I agree with the reasons against adding another number to the labels. The icon is also intuitive and I like it. As long as the user can find the number of cells missing/included, such as by hovering over the icon, I think it is useful.

Just to throw out another idea, what if the icon was a pie chart that conveyed the fraction of cells missing? Like a yellow wedge proportional to missing values? That way the user can tell at a glance the severity of the ‘warning’ for each label. This might be useful in cases where there are many categories like cell types, and it would be time consuming to hover over each label to check how many are missing.

[colinmegill]

I was afraid of that 😃

There are a number of disadvantages to doubling the number on the label, primarily:

• Variable amount of width, potentially quite a bit of space
• Confusion with the concept of ‘currently selected’ and ‘subset’, we don’t want to confuse the user with what fraction we’re displaying — the idea of ‘out of x’ is quite nuanced as the user might be looking at x cells (current selection) out of y subset out of z total.

I was thinking of something like this after the label itself, designating that there were missing values, that would provide more context on hover. I believe this should be yellow, for ‘warning’, and toggleable off to avoid distraction if unwanted.