How I compute multiple sum in matlab for 4D matrix?

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Mehdi 2018-9-11

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评论： Mehdi 2018-9-11

How I compute multiple sum in matlab for 4D matrices as below? U and V are 4D matrices.

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Mehdi 2018-9-11

编辑：Mehdi 2018-9-11

As I said I have many similar expressions like that and it seems your method is not applicable for more expressions. I am searching a similar command like add in Maple.

Matt J 2018-9-11

编辑：Matt J 2018-9-11

If they are "similar", my method - which is to use the sum command - is applicable. Have you read the documentation on sum()? It is the best analogue of add that you will find in Matlab.

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Matt J 2018-9-11

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编辑：Matt J 2018-9-11

在 MATLAB Online 中打开

Notice that the only indices shared between U and V are j and q. Therefore, you can minimize multiplication operations as follows,

partialU=sum(sum(U,4),1); %sum over i and r
partialV=sum(sum(V,4),1); %sum over k and s
A=sum(partialU(:).*partialV(:)); %sum over j and q

You should edit your original post with this new equation and information about q_r and q_s. The new expression is rather unclear. You have the symbol q being used for two different things, both as a symbolic variable and as an index of summation.

Mehdi 2018-9-11

I asked the question in new page as below: https://uk.mathworks.com/matlabcentral/answers/418526-what-is-the-best-way-to-calculate-multiple-summations-expression-in-matlab

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