issue_comments: 1216208075

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https://github.com/pydata/xarray/issues/4285#issuecomment-1216208075 https://api.github.com/repos/pydata/xarray/issues/4285 1216208075 IC_kwDOAMm_X85IfdzL 12912489 2022-08-16T06:38:32Z 2022-08-16T06:42:28Z NONE

@jpivarski

Support for event data, a particular form of sparse data.

I might have been misinterpreting the word "sparse data" in conversations about this. I had thought that "sparse data" is logically rectilinear but represented in memory with the zeros removed, so the internal machinery has to deal with irregular structures, but the outward API it presents is regular (dimensionality is completely described by a shape: tuple[int]).

You are right that "sparse" is misleading. Since it is indeed most commonly used for sparse matrix/array representations we are now usually avoiding this term (and refer to it as binned data, or ragged data instead). Obviously our title page needs an update 😬 .

logically rectilinear

This does actually apply to Scipp's binned data. A scipp.Variable may have shape=(N,M) and be "ragged". But the "ragged" dimension is in addition to the two regular dimensions. That is, in this case we have (conceptually) a 2-D array of lists. 

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