Given a collection of points, return the indices of the rows that contain the two points most distant from one another. The input vector p has two columns corresponding to the x and y coordinates of each point. Return ix, the (sorted) pair of indices pointing to the remotest rows. There will always be one unique such pair of points.
p = [0 0] [1 0] [2 2] [0 1]
ix = [1 3]
That is, the two points p(1,:) and p(3,:) are farthest apart.