Date: Nov 14, 2012 1:33 AM
Author: Jesse Pisel
Subject: Euclidean distance of all pairwise combinations (redundants)
I have been having a tough time trying to figure out how to include all red undant pairwise combinations in my results for the euclidean distance between a set of points. I have a set of points with xy coordinates and want the euclidean distance between each point including the point and itself. So if my points in xy space are list = {{1, 1}, {2, 2}, {3, 3}} for example, I want the distance from {1, 1} to {1, 1}, {1, 1} to {2, 2}, and {2, 2} to {3, 3} etc. for each point for a total of 9 distances all together. The EuclideanDistance function removes the redundant distances that I want retained in the results. I have been using this code just to play with data but would like to be able to expand up to 500+ points:

list = {{1, 1}, {2, 2}, {3, 3}}

EuclideanDistance @@@ Subsets[list, {2}]

Any ideas on how to get the euclidean distance between all the points including redundants and self references?