[R] Location of polr function

[Chuck Cleland]

Peter Flom wrote:
> 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.  

Load the MASS package prior to calling polr().

library(MASS)

-- 
Chuck Cleland, Ph.D.
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