how to partially multiply two diffferent dimention matrix

A[1,2500] and B[500,1]. how can i multiply 500 form A with B and then Skip 250 positions from A And multiply with B. e.g.., A[1 to 500]*B => store then A[250 to 750] * B=> store ,like wise

[John D'Errico]

Interesting. I wonder why two different people are asking the same question?

[kavinda hw]

this is the key technical part of our home work

Answer 1

[Star Strider]

This works:

A = randi(9, 1, 2500);                                          % Create Data
B = randi(9, 500, 1);                                           % Create Data
for k1 = 1:2
    Result{k1} = bsxfun(@times, A(1, (1:500)+(k1-1)*250), B);
end

It produces (500x500) matrices. If you what a different result, I need to know what output you want. It will be easy to change my code to produce it.

[kavinda hw]

Thank you for quick reply but I need 1x1 matrix

[Star Strider]

If you want the dot product (or inner product), change the ‘Result’ assignment to:

Result(k1) = A(1, (1:500)+(k1-1)*250) * B;

That will produce your (1x1) scalar result, as desired.

Answer 2

[Michael Saniuk]

>> A = rand(1250,1);
>> B = rand(1,500);
>> C = A(1:500,1).*B';
>> D = A(251:750,1).*B';