Matrix Multiplication is possible???

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Marwen
Marwen on 15 Aug 2013
Hi Can i programm under matlab Matrix multiplication generally without use of general entries
C = A*B is the linear algebraic product of the matrices A and B. If A is an m-by-p and B is a p-by-n matrix
Thanks

Answers (4)

Azzi Abdelmalek
Azzi Abdelmalek on 15 Aug 2013

Image Analyst
Image Analyst on 15 Aug 2013
What are "general entries"? If you want the matrix multiplication, simply do C=A*B like you said. If you want element-by-element multiplication, do C=A.*B. So I'm not sure what you're asking. Did you actually try C=A*B like you said - it's easy enough to do. If so, was there something unexpected that you observed?

Marwen
Marwen on 15 Aug 2013
Hi I develop simples examples like that A = [ 1 2 3; 4 5 6] B = [-5 8 11; 3 9 21;4 0 8] C=A*B
and enter i and j manually I hope you understand me
Thanks dear
  3 Comments
Marwen
Marwen on 15 Aug 2013
Edited: Azzi Abdelmalek on 15 Aug 2013
Hi Image analyste,
I want to develop something like that with Matlab :
nt A[50][50];
printf("Donner le nombre des lignes de la matrice A\n");
scanf("%d",&l);
printf("Donner le nombre des colonnes de la matrice A\n");
scanf("%d",&c);
printf("Enter les elements de la matrice A\n");
for(i=0;i<l;i++)
for(j=0;j<c;j++)
{
printf("Enter la valeur de A[%d][%d] ",i,j);
scanf("%d",&A[i][j]);
printf("\n");
}
i wish i clear my question thks
Image Analyst
Image Analyst on 15 Aug 2013
OK. I'm going to assume that the code you gave does what you want to do. I still don't see a question here, so I guess we're done.

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Azzi Abdelmalek
Azzi Abdelmalek on 15 Aug 2013
Edited: Azzi Abdelmalek on 15 Aug 2013
A=randi(10,5,6); % Example
B=randi(10,6,7);
p=size(A,2);
C=@(i,j) sum(A(i,:)'.*B(:,j))
% If i=2 and j=6 use
C(2,6)
Which is the same as
C=A*B
C(2,6)

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