How to multiply two matrices with nested for loops ?

How can I do that with two matrices with any dimensions that can multiply ? Thank you

[kale jabbar]

A=input

b=input

c=[ ]

R=size(A)

G=size(b)

n=R(1)

m=G(2)

for i=1:n

for j=1:m

c(i,j)=A(i,:)*b(:,j)

end

end

c

Answer 1

[Torsten]

A=rand(n,p);
B=rand(p,m);
C=zeros(n,m);

for i=1:n
  for j=1:m
     C(i,j)=0.0;
     for k=1:p
        C(i,j) = C(i,j)+A(i,k)*B(k,j);
     end 
   end 
end

Best wishes

Torsten.

[Denememe]

Thank you quick reply but i have an another problem. How can i multiply the intiger 5 with a matrix like [2 2 2 2; 2 2 2 2; 2 2 2 2] to get an answer like [10 10 10 10; 10 10 10 10; 10 10 10 10]

[Jan]

@Denememe: Please accept the answer to show, that the problem is solved. Open a new thread for a new question, because the Comment section is a bad location to do this.

Did you try to ask in internet search engine at first? You would have found the same code very fast. So please try to solve your homework by your own at first.

Answer 2

[KSSV]

https://in.mathworks.com/matlabcentral/answers/154803-how-to-multiply-matrices-using-for-loops

Answer 3

[pallab]

write a user define matrix multiplication function using if and for loop

[Walter Roberson]

Well, you certainly can do that, but you have not explained how to do that, and so this answer is not at all useful in answering the question posed of how to write such code.

I admit to being rather unclear as to the benefit of using "if" statements in the matrix multiplication code? I can see using "if" in the initial tests to verify matrix size compatibility though.