Hi all, My question is really more statistical theory than about R, however I would greatly appreciate if someone can provide guidance. I am trying to measure distance between points given j number of variables, a subset of which is latitude and longitude. To make the distance scale-invariant, I use Mahalanobis distance. Is this a correct way of measuring distance in j-dimensional space given that latitude and longitude should be taken jointly? Cheers, Michael -- "I am most anxious for liberties for our country... but I place as a prior condition the education of the people so that our country may have an individuality of its own and make itself worthy of liberties... " Jose Rizal,1896 [[alternative HTML version deleted]]