How can I sort the rows of a matrix in descending order in MATLAB 7.0.1 (R14SP1)?

I have a matrix A defined as follows:

A = [7 1;2 4;5 1;3 2];

I would like to sort the rows of A in descending order along the first column.

Answer 1

[MathWorks Support Team]

The SORTROWS function offers the ability to sort the rows of a matrix in descending order by specifying a negative value for the appropriate column in the second argument to the function.

For example, the following call to SORTROWS will sort the rows of matrix A by descending order of column 2 and then by ascending order of column 1:

B = sortrows(A,[-2 1])

 B =

      2     4

      3     2

      5     1

      7     1

This feature is documented in the function reference for SORTROWS in the documentation in MATLAB versions 7.1 (R14SP3) and higher. For previous versions you may consult the file help content which contains this information by executing the following at the MATLAB prompt:

help sortrows