[R] Handling of NAs in functions lrm and robcov

[Christof Bigler]

I was pointed by Andy Liaw to use rownames(model.lrm$x) as index to 
clus.

Thanks!
Christof

> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Christof Bigler
> Sent: Monday, March 22, 2004 5:11 PM
> To: R-help
> Subject: [R] Handling of NAs in functions lrm and robcov
>
>
> Hi R-helpers
>
> I have a dataframe DF (lets say with the variables, y, x1,
> x2, x3, ...,
> clust) containing relatively many NAs.
> When I fit an ordinal regression model with the function lrm from the
> Design library:
> model.lrm <- lrm(y ~ x1 + x2, data=DF, x=TRUE, y=TRUE)
> it will by default delete missing values in the variables y, x1, x2.
> Based on model.lrm, I want to apply the robust covariance estimator
> using a cluster variable:
> model.robcov.lrm <- robcov(model.lrm, cluster=clust)
> How can I remove observations in the cluster variable clust that
> contain NAs in y, x1, and x2?