Vectorization of a nestled loop

I am trying to improve the overall performance of my code and I am learning about vectorization. I've read the documentation on this but I'm having a hard time with even seemingly simple parts of the code. I have the following loop

dndt=zeros(m,1);   
for i=1:n
        for j=1:m
            dndt(j,1)=dndt(j,1)+matA(i,j)*B(i);
        end
    end

Where matA is a n x m matrix and B is a vector of size n. I'm not sure how to do this.

Any tips or help is appreciated, thank you!

Answer 1

[Stephen23]

You can use matrix multiplication:

matA.'*B(:)

which gives an output with size mx1, just like your nested loops. Even simpler:

B*matA

which gives an output with size 1xm.

[AM]

It works perfectly, thank you!