Question

I have a time series for which I have a function that returns the local maxima and minima in a matrix that is sorted in descending order by the y coordinate. For example, running it on the following series:

[1 7 3 7 10 12 6 4 6]

would return:

{ {6 , 12}, {2, 7}, {9, 6} }

As the local maxima. How can I sort this matrix so that it is sorted by the index in ascending? I want:

{{2, 7}, {6, 12}, {9, 6}}

EDIT:
I’ve actually modified my function to just return values in index-sorted order. But I would still like to know the best way of doing this (sorting a matrix by one column value).

Answer 1

You want sortrows(). Note, however, that it works on standard arrays, not the cell arrays that you’ve shown in your question. For example:

>> m = [ 6 12; 2 7; 9 6 ];
>> sortrows(m)

ans =

     2     7
     6    12
     9     6