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Multiply each column of n-by-m matrix by respective constants in m-by-1 vector

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Jesper on 21 Jan 2012
Commented: Steven Lord on 23 Jul 2021
I have an n-by-m matrix and an m-by-1 vector. I want to multiply each of the m columns in the matrix by a constant specified in my vector.
E.g. if I have a matrix A=[1,2;3,4;5,6] and a vector B=[0.5,2] I want to multiply all the elements in the first column of my matrix by 0.5 and alle the elements en the second column by 2. That is, I would like to get the result C=[0.5,4;1.5,8;2.5,12].
It can easily be done by a loop, but I would like to know if the is a faster way to do this. A built in functionality? Dot-multiply doesn't seem to do the trick :(
Thanks in advance!
- Jesper

More Answers (2)

vlad ap
vlad ap on 22 Jul 2021
This also works:
C = B.*A

Jesper on 21 Jan 2012
Hi Cyclist
This was exactly what I needed ;)
- Jesper
  1 Comment
the cyclist
the cyclist on 21 Jan 2012
Happy to help. For future reference, you might want to add a remark like this as a "comment" to an answer (like I did here), rather than as a separate "answer". On questions that have more activity than this one, it helps to keep things organized logically.

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