[R] Re: Error in model.frame SOLVED

[Ross Boylan]

On Fri, 2003-08-15 at 16:15, Ross Boylan wrote:
> On Fri, 2003-08-15 at 16:03, Ross Boylan wrote:
> > I am getting an error that I don't understand, and wonder if anyone
> > could explain what's going on.  I call a function defined thus:
> > 
> > clogit.rds<-function(formula,data,extra.data,response.prob,
> >                  na.action=getOption("na.action"),subset=NULL,
> >                  control=coxph.control()){
> >     method="exact"  # only option for now
> >     mf<-match.call()
> >     mf[[1]]<-as.name("model.frame")
> >     mf$method<-mf$control<-NULL
> >     mfn<-mf
> > 
> >     mfn$na.action<-"I"
> >     mfn$subset<-NULL
> >     nrows<-NROW(eval(mfn,parent.frame()))
> > etc.
> > At the eval on the last line, I get
> > 
> > Error in model.frame(formula, rownames, variables, varnames, extras,
> > extranames,  : 
> > 	variable lengths differ
> > 
> A clue: if I call this with response.prob set to an element of the
> clogit.rds argument data frame, I don't get the error.
> 
> I assume that to fix this I must somehow exclude this variable.  But I
> will need it back in when I make the next call.  Suggestions?  Insights
> into why this is necessary?

I need mf$response.prob <- NULL to make it work.
Still wonder why model.frame is so picky....
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