Look up a value in an incomplete list
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I have keys and values like this:
keys = ["a", "b", "c", "d"];
vals = [3,4,2,1];
and I need to look up the values for x, but not all keys exist, e.g.:
x = ["c", "d", "e"];
which should result in:
y = [2, 1, NaN];
The problem I have is that strfind(), matches() yield empty arrays for "e", which leads to errors when looking up in vals.
Also, all arrays are >100k so I would like to avoid a for-loop.
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DGM
2022-2-21
How about:
keys = ["a", "b", "c", "d"];
vals = [1,2,3,4];
x = ["c", "d", "e"];
[~,y] = ismember(x,keys);
y(y==0) = NaN
2 个评论
DGM
2022-2-21
Oof. I forgot about that.
keys = ["a", "b", "c", "d"];
vals = [11,22,33,44];
x = ["c", "d", "e"];
[m idx] = ismember(x,keys);
y = NaN(size(m));
y(m) = vals(idx(m))
另请参阅
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