Displaying 1 result from an estimated 1 matches for "populationdensity".
2007 Jul 26
1
zeroinfl() or zicounts() error
I'm trying to fit a zero-inflated poisson model using zeroinfl() from the
pscl library. It works fine for most models I try, but when I include either
of 2 covariates, I get an error.
When I include "PopulationDensity", I get this error: Error in solve.default
(as.matrix(fit$hessian)) : system is computationally singular:
reciprocal condition number = 1.91306e-34
When I include "BuildingArea", I get this error: Error in optim(fn =
loglikfun, par = c(start$count, start$zero, if (dist == :...