Extracting rows from a matrix based on values in columns

Question

0 个投票

Following on from this question

What if I have more than 1 column? That is, I want A to be a 6-by-4 matrix for example, so to have C{1} = 4-by-3 matrix?

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显示 -2更早的评论隐藏 -2更早的评论

Answer 1

Guillaume 2017-10-8

1 个投票

It's much easier to do this with the newer splitapply rather than the older accumarray:

A = [[1;1;3;2;3;1], rand(6, 3)]
C = splitapply(@(rows) {rows}, A(:, 2:end), A(:, 1))

Cedric 2017-10-8

I am up-voting even though ...

;)

Maria445 2017-10-8

Awesome, thanks!

Answer 2

1 个投票

    for n=2:4, C_temp(:,n-1) = accumarray(A(:,1),A(:,n),[],@(n){n}); end
    for m=1:size(C_temp,1), C{m} = cell2mat(C_temp(m,:)); end