Assume that x is an n-by-2 matrix. The aim is to return the first column of x, but sorted according to the second column.
Example:
Input = [1 2 3 4 5;
4 3 1 2 2]'Output = [3 4 5 2 1]'
Please! Can you explain more than that?
Aye! The first column is not "sorted according the second column" (only half an explanation). The block of numbers in each row is treated as a fixed unit, and each row is rearranged such that the values in the second column are sorted in ascending order.