Hai Viviane,
your link to the data seems to be broken (No such file).
However I tried to reproduce your problem using the data from [1] and
could not reproduce this:
library(nlme)
snouter.df -
read.table('http://www.oikos.ekol.lu.se/appendixdown/snouterdata.txt',
header=T, sep=\t)
Hi everyone,
I recently did an analysis using WinBUGS to describe the vegetation
associated with a number of South American birds (Journal of Field
Ornithology 84:1-12).
Now I would like to do the same analysis but compare the vegetation where
birds forage with random sites in forest fragments
*error for node smtree[1] of type GraphPoisson.Node first argument must be
positive*
You're using negative (must be positive) value to lambda parameter in
Poisson distribution.
You should start checking this line:
*mean[i] - alpha[site[i]] + re[i]
*
and find why mean[i] is returning negative
