matlab sort 2 columns: column 1 descending and column 2 ascending

Question

I have a 3 column array like this:

A = [6 -1 0;
     6  0 3;
     1  4 3;
     1  2 5];

I need the first column to be in descending order and

Answer 1

If the third column is to be unchanged,

 B = A;
 B(:,1) = sort(B(:,1),'descend');
 B(:,2) = sort(B(:,2),'ascend');

If you want the third column to change with the second then,

[B(:,2),ind] = sort(B(:,2),'ascend');
B(:,3) = B(ind,3);

B =

 6    -1     0
 6     0     3
 1     2     5
 1     4     3

Answer 2

If you're looking to keep the rows intact as records, and sort them based on column 1 and then column 2, use sortrows(), with negative column indexes to indicate columns whose values are to be sorted in descending order.

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