I didn't understand how put the inputs in tprod function

How have I to put the input in tprod to have the same result of the code that follows?

a=rand(3,4,5);
b=rand(4,6);
for i=1:5
       c(:,i,:)=a(:,:,i)*b;
end

[edit: matrix dimension corrected]

Answer 1

[Fangjun Jiang]

a=rand(3,4,5);
b=rand(3,4);
c=zeros(size(a));

for i=1:5
       c(:,:,i)=a(:,:,i).*b;
end

Or do you mean this link? There is a 3-D example there. http://www.mathworks.com/matlabcentral/fileexchange/16275-tprod-arbitary-tensor-products-between-n-d-arrays/content/tprod.m

Okay, I tried, it should be like below. The original tprod.m does contain incorrect examples.

%%Your code
a=rand(3,4,5);
b=rand(4,6);
for i=1:5
       c(:,i,:)=a(:,:,i)*b;
end

% use tprod
Z=tprod(a,[1 -1 2],b,[-1 3]);

err=abs(Z-c);
err=sum(err(:))

err =

       0

[Francesco]

Thank you, Fangjun Jiang, but I had in mind

c=tprod(a,[ ... something ... ],b,[ ... something ... ]);

[Fangjun Jiang]

That is the problem! You need to at least provide some explanation about tprod. It's not a MATLAB function anywhere. Do you mean this?

http://www.mathworks.com/matlabcentral/fileexchange/16275

[Francesco]

Yes, I meant right it.

Answer 2

[Walter Roberson]

What is "tprod" ? It does not seem to be indexed on the MATHWORKS web site.

Your code produces an error, as at each step you are attempting to do a matrix multiplication of a 3 x 4 matrix, by a 3 x 4 matrix. Either you need to use .* to do element-by-element multiplication, or you need to change your formula.

[Francesco]

tprod is a function to multiply n-dimensional arrays (http://www.mathworks.com/matlabcentral/fileexchange/16275-tprod-arbitary-tensor-products-between-n-d-arrays)

About the dimensions: you're right, I corrected them right now, thanks.