how can i do Matrix multiplication with 3 matrices

Hello everyone,

I have 3 matrixs with dimensions;

x[36,36] , rij[36,36], and ai[36,1]

i wanna multpily these matrixes and sum each of them. what i want should look like this;

x(1,1)*r(1,1*ai(1)+x(1,2)*r(1,2)*ai(1)+.....+
x(2,1)*r(2,1)*a(2)+x(2,2)*r(2,2)*a(2)+....+
x(36,1)*r(36,1)*a(36)+x(36,36)*r(36,36)*a(36)

i have tried this;

z= sum((x.*rij)*a,'all'); 

but this is doing this ;

x(1,1)*r(1,1*ai(1)+x(1,2)*r(1,2)*ai(2)+.....+x(2,1)*r(2,1)*a(1)+x(2,2)*r(2,2)*a(2)+....+ x(36,1)*r(36,1)*a(1)+x(36,36)*r(36,36)*a(36)

But this is not i want!

Hope what i want to do is clear!

Thank you in advance!

[Walter Roberson]

Are you sure that the second indices for r should be calculated in terms of ai(1) ?

x(1,1)*r(1,1*ai(1)+x(1,2)*r(1,2)*ai(1)+.....+
           ^^^^

Notice that you did not close the ) after r(1,1

x(2,1)*r(2,1)*a(2)+x(2,2)*r(2,2)*a(2)+....+

Notice that you do close the ) after r(2,1) .

[Azime Beyza Ari]

Sorry for that, it is a typo. It should be closed.

Answer 1

[Bruno Luong]

sum(x.*rij,2)' * ai

[Azime Beyza Ari]

Thank you! This was what I needed.