How can I sort a cell array according to one column's order?
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Hi, I have a cell array of (50, 2), each cell in the first column contains a 4x960 matrix but the cells in the second column are 1x1 numbers. Each cell in the second column shows the rank for the matrix in the same row of the cell array. For example cell(1,1) is a 4x960 matrix and it's rank is in cell(1,2). I want to sort this cell array according to the rank(second) column, meaning that if a matrix (in the first column) has the highest rank(in the second column) and needs to be moved to the last row(descending order), it's matrix in the first column should move with it to the last row, too. Would you please help me?
Answers (1)
Alexandra Harkai
on 31 Oct 2016
There may be a conflict in what you define to be of 'descending order':
"if a matrix (in the first column) has the highest rank(in the second column) and needs to be moved to the last row(descending order), it's matrix in the first column should move with it to the last row, too"
This example goes with the "first row will have the smallest rank" way:
A; % this is the input cell array
[ranks_ordered, idx] = sort(cell2mat(A(:,2)));
B = A(idx,:);
sort returns the sorting indices as the second output argument, which is then used to re-sort the original cell array.
4 Comments
Alexandra Harkai
on 31 Oct 2016
ranks_ordered will be a numeric array from the rank values (second column of the original cell array), so the type changes there, but the original data is unchanged, it stays a cell array.
Check what B gives once you run the code. A(idx,:) indexes the rows (first 'coordinate') of A, and does this to the whole contents of the rows, explained here.
Sherwin
on 31 Oct 2016
Alexandra Harkai
on 31 Oct 2016
Np, hope that explains all.
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