How to vectorize this "for" loop, or parallel it.
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fun = @(x,y) x + x.*y;
N = 1e3;
K = zeros(N);
for i = 1:N
for j = i:N
K(i,j) = fun(i, j);
end
end
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Answers (2)
Azzi Abdelmalek
on 23 Jan 2014
Edited: Azzi Abdelmalek
on 23 Jan 2014
fun = @(x,y) x + x.*y;
N=1000
[y,x]=meshgrid(1:N,1:N);
out=triu(fun(x,y))
2 Comments
Azzi Abdelmalek
on 23 Jan 2014
Edited: Azzi Abdelmalek
on 23 Jan 2014
N=4000;
tic
fun = @(x,y) x + x.*y;
[y,x]=meshgrid(1:N,1:N);
f=triu(fun(x,y));
toc
tic
K = zeros(N);
for i = 1:N
for j = i:N
K(i,j) = fun(i, j);
end
end
toc
isequal(f,K)
Elapsed time is 0.193062 seconds.
Elapsed time is 2.421795 seconds.
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