Hi all R users ! I'm using gamm function from Simon Wood's mgcv package, to fit a spatial regression Generalized Additive Mixed Model, as covariates I have the geographical longitude and latitude locations of indexed data. I include a random effect for each district (dist) so the code is
fit <- gamm(y~s(lon,lat,bs="tp", m=2)+offset(log(exp.)), random=list(dist=~1), family="poisson", niterPQL=30) when I run the gamm function I obtain the next error message: %%% Maximum number of PQL iterations: 30 iteration 1 iteration 2 ... iteration 8 iteration 9 iteration 10 Error in chol(XVX + S) : the leading minor of order 29 is not positive definite %%% Could be any problem in gamm() ??? -- [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.