how to apply a function to all rows in a matrix?

Question

Consider for example the function "norm". I have a matrix, and I want to apply "norm" to each row in the matrix, and get a vector of all norms for each row in this matrix.

I was hoping I could do norm(A, 'rows'), but that is not possible. Is there some other way to do it?

score 9 · Answer 1 · answered Oct 31 '13 at 10:32

9

You can do it without converting to a cell array:

arrayfun(@(n) norm(A(n,:)), 1:size(A,1))

answered Oct 31 '13 at 10:32

Luis Mendo

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+1 Easier and apparently faster than converting to cell. – Oct 31 '13 at 10:35

score 1 · Answer 2 · answered Oct 31 '13 at 10:23

1

Like this?

M = 1e4;
N = 1e3;
A = randn(M, N);

% Solve
B = mat2cell(A, ones(M, 1), N);
b = cellfun(@norm, B);

Maybe arrayfun could be used instead?

answered Oct 31 '13 at 10:23

how to apply a function to all rows in a matrix?

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