How to loading a vector with values from a logical index
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I have a vector, Vin, of length m. I also have a logical vector, Idx, to select indices to work on (subset size n < m). I can operate on Vin(Idx) and get Vdata of length n. This is all good. But now I want to generate a new Vout vector that is filled with the values from Vdata at the appropriate index. This can be accomplished by the following code snippet.
Vout=zeros(length(Vin));
k = 1;
for j = 1:length(Vin)
if Idx(j)
Vout(j) = Vdata(k);
k = k + 1;
end
end
This seems verbose ? Is there a more efficient or correct way of doing this? i want the output vector to be of length m, not n
回答（1 个）
Sara
2014-7-16
Vout = Vin(Idx)
4 个评论
Timothy Carnahan
2014-7-16
Sara
2014-7-16
Vout = zeros(length(Vin),1);
Vout(Idx) = Vin(Idx);
Timothy Carnahan
2014-7-16
Sara
2014-7-16
You may want to do zeros(length(Vin),1), otherwise you get a square matrix instead of a 1d array for Vout
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2014-7-16
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