[R] polr

[grazia at stat.columbia.edu]

Dear R heplper,
I'm using polr:

fm <- polr(factor(y) ~ x, ,method='logistic', data = dat, Hess=T)

ans I'm getting a very strange message:
Error in optim(start, fmin, gmin, method = "BFGS", hessian = Hess, ...) :
initial value in 'vmmin' is not finite
Can you help me?
Thank you in advance,
Grazia


----
M. Grazia Pittau, Ph.D.
Post-Doctoral Research Fellow
Department of Statistics
Columbia University
1255 Amsterdam Avenue
New York, NY  10027

grazia at stat.columbia.edu
Phone: 212.851.2160
Fax: 212.851.2164