MATLAB: Summin elements on the rows of a specific page of a matrix

arrayindexindexingmatrixpagessum

If I have a matrix A(n,m,2) i.e. a two pages matrix, and a vector B(n,1), how should I write the expression for the j-th element of b, if I want B to contain the sum of the elements of the rows of the first page of A?

Best Answer

B = sum(A(:, :, 1), 2);  %sum 1st page of A across the columns (across the 2nd dimension)

Related Solutions

MATLAB: How to extract elements along one dimension in an n-d array based on an arbitrary criterion.

One possible way, using ind2sub:

[~, page] = min(abs(A), [], 3);
[rows, columns] = ndgrid(size(A, 1), size(A, 2));
B = A(sub2ind(size(A), rows, columns, page));

MATLAB: Set output when index is out of bounds

mask = A(:,:,1) <= p;
mask1 = cat3(mask, false(size(A,1),size(A,2)));
mask2 = mask1(:,:,[2 1]);
result = B(A(mask1)) .* A(mask2));

Best Answer

Related Solutions

MATLAB: How to extract elements along one dimension in an n-d array based on an arbitrary criterion.

MATLAB: Set output when index is out of bounds

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