[GRASS-stats] How to calculate the Bhattacharyya distance/index?

[Nikos Alexandris]

Agus,

I really appreciate your kind support. It's important to have some hand
to push you a bit when you are stuck :-) I am convinced that you know
that better than many other people.

The problem is that I must use it wrong. I have 42 samples (number of
pixel varies and is not really too big) extracted from:

(1) a 3x3 matrix with columns MODIS prefire.band2, prefire.band 6 and
prefire.band7

(2) a 3x3 matrix with columns MODIS postfire.band2, postfire.band 6 and
postfire.band 7

When I feed these two as PRE and POST in my function JM <-
function(PRE,POST) etc., I get a Bhattacharayya distance of -50.xxx and
the JM becomes something like -7.xxx

As you might have noticed I use colMeans() to calculate each bands mean.
I really am stuck and can't seem to understand what I am doing wrong. Is
it really that difficult? :-0

Thank you in advance, of course even if you don't have the time to
reply. Nikos