For loop over each dimension of a n-dimensional matrix

I am trying to use a 1:n vector to populate a n-dimensional matrix. The matrix should describe the sum of some of the elements of the vector. For example, for n=4, myMatrix(1,1,2,2) is the sum of the third and fourth element of the vector, myMatrix(2,2,2,2) is the sum of all of the elements of the vector, etc.

The following works for n=4 elements, but I am not sure how to write it as a loop, and for an arbitrary number n.

n=4;
myVector = normrnd(0,1,[1,n]); % Get a vector of n random numbers 
myMatrix = zeros(ones(1,n)*2); % Initiate the 2x2x2x2 matrix

myMatrix(2,:,:,:) = myMatrix(2,:,:,:) + myVector(1)
myMatrix(:,2,:,:) = myMatrix(:,2,:,:) + myVector(2)
myMatrix(:,:,2,:) = myMatrix(:,:,2,:) + myVector(3)
myMatrix(:,:,:,2) = myMatrix(:,:,:,2) + myVector(4)

Many thanks if you are able to help with this!

Answer 1

[DGM]

Something like this:

n = 4;
myVector = normrnd(0,1,[1,n]); % Get a vector of n random numbers 
myMatrix = zeros(ones(1,n)*2); % Initiate the 2x2x2x2 matrix

for d = 1:n
	% this is building the list of indexing expressions
	idx = repmat({':'},[1 n]); % this is :,:,:,...
	idx{d} = 2;
	
	% then you can use them like so
	myMatrix(idx{:}) = myMatrix(idx{:}) + myVector(d)
end

[David Mao]

This is amazing, I did not know it was possible to index like that! Thank you so much!!