[R] Distance between sets of points in transformed environmental space

Charlotte Maia maiagx at gmail.com
Tue Dec 1 11:19:51 CET 2009


Well, here's another naive post from me (hopefully better than the last one).

Firstly I'm not sure computing euclidean distance is that simple. I
would assume temperatures and precipitation would need to be
standardised in some way.

I think the notion of how far away something is, and how distinct
location wise something is, are quite different, so maybe two
measures?

For distance per se, I think your first idea is the best.
Plus simple is always good...

For distinctness, given one one of two sets, for each point, you could
just compute the closest point to it. If the closest point is a member
of the same set, we will call that a + point, if the closest point is
a member of the other set, we will call it a - point. In principle the
measure of distinctness would be the sum of the +'s, however there
might need to be some scaling to take into account the number of
points in each set.

There are also a lot of fancy things out there, so someone will
probably come up with a much fancier (and possibly better) idea than
this.

Well, that's just my rant, before I go to bed.


kind regards
-- 
Charlotte Maia
http://sites.google.com/site/maiagx/home




More information about the R-help mailing list