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Two arrays specifying index pairs for a another array -- how to vectoriz
From: |
Jason |
Subject: |
Two arrays specifying index pairs for a another array -- how to vectorize? |
Date: |
Fri, 12 Mar 2010 19:06:02 +0000 (UTC) |
User-agent: |
Loom/3.14 (http://gmane.org/) |
Hello,
I have a 2D array, say 'A'. I also have two 2D arrays, say 'ix' and 'iy'. I
would like to make a third 2D array, whose elements are the elements of A at the
index pairs specified by ix and iy. I can do this with a loop as follows:
for i=1:nx
for j=1:ny
out(i,j) = A(ix(i,j),iy(i,j));
end
end
Is there a way I can do this with matrix/vector operations? If I do
out=A(ix,iy), that will give me an (nx*ny)X(nx*ny) array using all the possible
pairs of values in ix and iy. Any ideas?
Thank you,
Jason
- Two arrays specifying index pairs for a another array -- how to vectorize?,
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