randomness

[Darrell McCauley]

Michael Shapiro (shapiro at zorro.cecer.army.mil) writes on 5 Aug 93:
>In <9307221717.AA06419 at pasture.ecn.purdue.edu> mccauley at ecn.purdue.edu (Darrell McCauley) writes:
>>Not only do I need to generate random
>>points, but I also need to use them to
>>randomly select sites, perhaps using a
>>nearest neighbor approach. This is for a
>>k-fold cross validation of some
>>interpolation methods.  Would anyone else

for those who may have missed it, s.rand
and s.kcv are available for testing on
pasture.ecn.purdue.edu in pub/mccauley/grass

>generates numbers between 0.0 and 1.0. Read
>Number Recipes in C for a discussion about
>random number generators and ways to generate
>various kinds of distributions.

generating a Poisson simply means that
coordinates come from a uniform distribution.

Cressie outlines several indices for quadrat
count data and statistics for nearest neighbor
distances (event to nearest event, sample point
to nearest event, sample point to second-nearest
event, etc). If anyone is interested a GRASS 
program to compute these, contact me.

--Darrell