CODEWITHSUNDEEP
arraysmatlabmatrix
Mazhar Iqbal Rana
Mazhar Iqbal Rana

Reputation: 17

Element wise multiplication of every row/column of a matrix with a vector

I have a matrix, named as p_c_w having dimensions 6X7599 and the other matrix named as p_w having dimensions 1X7599. I wish to have their element-wise multiplication but I am unable to do that. For size of rows of p_c_w and columns of p_w to be same, I have taken transpose of p_c_w and stored it in anss. Error I am receving is: Subscripted assignment dimension mismatch.

Code is below. Can anyone please help?

Thanks a lot in advance

anss=p_c_w'
for i=1:size(anss,1)
for j=1:size(p_w,2)
    temp(j,i)=anss(i,j).*p_w(j);   
end
end

Upvotes: 0

Views: 1625

Answers (2)

Navan
Navan

Reputation: 4477

From R2016b release, you do not need to use bsxfun for this operation. For example, the following code will do the same thing as @thewaywewalk's answer.

A = [ 1 2 3 4 5;
      1 2 3 4 5;
      1 2 3 4 5 ];

B = [ 1 10 100 1000 10000];

C = A.*B

Check out doc for implicit expansions.

Upvotes: 0

Robert Seifert
Robert Seifert

Reputation: 25232

use bsxfun:

A = [ 1 2 3 4 5;
      1 2 3 4 5;
      1 2 3 4 5 ];

B = [ 1 10 100 1000 10000];

C = bsxfun(@times,A,B)

returns:

C =

           1          20         300        4000       50000
           1          20         300        4000       50000
           1          20         300        4000       50000

Works the same for A' with B'

so for your case:

temp = bsxfun(@times,p_c_w,p_w)

Upvotes: 3

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