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Topic: subtract vector from matrix rows without for loop
Replies: 6   Last Post: Dec 6, 2012 11:49 PM

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Remus

Posts: 5
Registered: 7/31/11
Re: subtract vector from matrix rows without for loop
Posted: Dec 6, 2012 11:48 PM
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"Matt J" wrote in message <hesupb$i07$1@fred.mathworks.com>...
> "Patrick Diviacco" <patrick.diviacco@gmail.com> wrote in message <hesm3s$3sn$1@fred.mathworks.com>...
> > hi,
> >
> > can I subtract the same vector to each row of a matrix without using a for loop ?
> > thanks

>
> For loops may be optimal (looping along the smallest dimension of the matrix), when the smallest dimension is small enough.


I like Matt's answer... here is another way of doing it, slightly more efficient.

A = magic(3);
B = [ 1 2 3];
C = A-diag(B)*ones(size(A));

In essence is the same thing.



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