[R] Location of polr function

[Peter Flom]

Hello

I am running R 1.8.1 on a  Windows platform

I am attempting to fit an ordinal logistic regression model, using the
polr function, as described in Venables and Ripley.  But when I try

model4 <- polr(ypsxcat~committed + as.factor(sex)
 + as.factor(drugusey) + anycsw + as.factor(sex)*committed
  + as.factor(sex)*as.factor(drugusey)+as.factor(sex)*anycsw, data =
duhray)

I get a message that the polr function was not found.  

Any help appreciated

thanks

Peter

Peter L. Flom, PhD
Assistant Director, Statistics and Data Analysis Core
Center for Drug Use and HIV Research
National Development and Research Institutes
71 W. 23rd St
www.peterflom.com
New York, NY 10010
(212) 845-4485 (voice)
(917) 438-0894 (fax)