Hello
I am doing a project on ordered logit/probit models using Splus. I am
using the polr function in library(MASS) which is exactly the same code as
in R. Unfortunatelly I am not very succesfull with it. The code I used
was:> polr(factor(resp)~.,data=data3) # data3 does not consist the resp
variable
But I am getting the same warning message 21 times. The message is the
following:
1: singularity encountered in: nlminb.1(temp, p, liv, lv,
objective, gradient, bounds, scale)
I guess the corresponding warning message in R is:
Error in optim(start, fmin, gmin, method = "BFGS", hessian = Hess)
I would be very greatfull if someone could suggest what it might be wrong
with
my model anh how I can overcome it.
Thanking you in advance
Charis Spanou