How to subtract from a vector a three dimentional matrix

Question

gsourop 2016-12-12

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https://ww2.mathworks.cn/matlabcentral/answers/316548-how-to-subtract-from-a-vector-a-three-dimentional-matrix

评论： Adam 2016-12-12

Hi everyone,

I have a 1x12 vector and a 3x2x12 matrix, say i x j x t. I want to subtract for each i and for each j the corresponding vector of t. I've tried the following, but it doesn't work.

for t=1:12
for j=1:2;  %size(inputs,1);
for i=1:3  %10;
    MSFE_i(i,:,j)=mean((y(1:12)'-forecasts_test(i,j,:)).^2);
end 
end
end;

any ideas of what i am missing here? Thanks in advance.

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Answer 1

Adam 2016-12-12

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https://ww2.mathworks.cn/matlabcentral/answers/316548-how-to-subtract-from-a-vector-a-three-dimentional-matrix#answer_246879

编辑：Adam 2016-12-12

在 MATLAB Online 中打开

for example:

a = ones( 3, 2, 12 );
v = linspace( 0, 1, 12 );
res = reshape( bsxfun( @minus, reshape( a, [], 12 ), v ), [3, 2, 12] );

Obviously you can generalise the hard coded numbers and you don't need all the linspace stuff - I just used that to create a vector for me to subtract and then check the results quickly.

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gsourop 2016-12-12

Thank you very much for the quick response. My question is that you have created a new matrix v = linspace( 0, 1, 12 ); , but in my case the respective matrix has already values, ie it is a fixed vector with returns. How can I resize it to look like v = linspace( 0, 1, 12 ); ?