[R] Remove observations deemed influential by influential.measure

[David Winsemius]

On Jun 29, 2010, at 1:10 PM, GL wrote:

>
> dbs is an existing dataframe. I fit a lm and looked at influential
> observations. I want now to delete the influential observations from  
> dbs,
> fit another lm, and see how different the results are. What is the  
> syntax to
> remove the influential observations from dbs?
>
> fit <- lm(NI ~ PG + log(TG), data=dbs)
> fit.influential.observations <- influence.measures(fit)
>
> dbs.without.influential.observations <- ?????
>

Look (more?) carefully at the examples on the help page. The first  
example shows how to extract a vector of row numbers associated with  
infuential cases. If you need help applying htat information to a  
dataframe using "[" then you probably need to re-read the Introduction  
to R as well.

-- 

David Winsemius, MD
West Hartford, CT