vector matrix multiplication single row

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PK
PK on 23 Oct 2012
is there a chance to multiply this way rand(1,10)*rand(10,100) but the way of calculation is each singe element of 1x10 mtx should multiply entire row of 10x100 mtx

Answers (2)

Andrei Bobrov
Andrei Bobrov on 23 Oct 2012
a = rand(1,10);
b = rand(10,100);
out = bsxfun(@times,a.',b);

Jan
Jan on 23 Oct 2012
Edited: Jan on 23 Oct 2012
While I'd prefer BSXFUN as Andrei has posted already, there is an alternative:
a = rand(10,1); % Transposed!
b = rand(10,100);
R = a(:, ones(1, 100)) .* b;
Time measurements seems like the ONES is not created explicitely, such that this is more efficient than it looks like.

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