I didn't understand how put the inputs in tprod functionHow 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] Products |
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2 answers
Fangjun Jiang answered
on 19 Aug 2011
%% 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
3 comments
Francesco
on 19 Aug 2011
Thank you, Fangjun Jiang, but I had in mind
c=tprod(a,[ ... something ... ],b,[ ... something ... ]);
Fangjun Jiang
on 20 Aug 2011
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
on 20 Aug 2011
Yes, I meant right it.
Walter Roberson answered
on 19 Aug 2011
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.
1 comment
Francesco
on 20 Aug 2011
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.
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