Vectorized Data Extraction from Cell Array

1 次查看（过去 30 天）

Gabriel Stanley 2022-9-19

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1808060-vectorized-data-extraction-from-cell-array

编辑： Image Analyst 2022-9-20

I have a Nx1 cell array wherein each cell is a #x2 double array (i.e. each array within the cell is of variable length). CellArray{n}(:,1) contains a list of data indecis, while CellArray{n}(:,2) contains values associated with those indecis. I want to get a unique list of all values in that first column from all cells, then perform operations on each value associated with a given data indexi accross all cells, e.g.:

Indecis = unique(CellArray{:}(:,1))
Results = mean(CellArray{:}(Indecis,2))

The above is, of course, not proper MatLab syntax, but I hope it conveys what I'm trying to do. I can achive this rather simply by using cell2mat,

DataMatrix = cell2mat(CellArray);

But whos is telling me that DataMatrix is waaaaaaay bigger than CellArray. As such, I'd like to know if there is a less data/processor intensive way to do this (e.g. cellfun with an annonymous function handle?).

4 个评论
显示 2更早的评论隐藏 2更早的评论

dpb 2022-9-19

Just a nit-picky note that in English, the plural of "index" is "indices"...

Image Analyst 2022-9-19

编辑：Image Analyst 2022-9-20

@dpb the language has evolved since you and I were young. I think the "ices" may have been a holdover from Latin but now "indexes" has evolved into a perfectly acceptable plural of index. See https://www.dictionary.com/browse/index So both "indices" and "indexes" are correct, however, "indecis" is not correct.

I've also heard that "whom" is going away, in favor of a simpler "who", and maybe considered almost archaic in a few decades, if not already.

https://qz.com/1517643/should-we-let-the-word-whom-die/

https://www.quora.com/Would-you-say-the-word-whom-has-already-become-archaic-or-do-you-think-it-is-still-grammatically-relevant-in-modern-writing

https://www.dailywritingtips.com/who-cares-about-%E2%80%9Cwhom%E2%80%9D-anymore/

Speaking of simplification: