[R] is.na<- doesn't seem to work with labelled variables?

[Nikhil Kaza]

a <-  c(1, 8, 9, 10, 8)
a[which(a==8)] <- NA

Nikhil

On Apr 6, 2010, at 7:31 AM, David Foreman wrote:

> Dear All,
>
> I seem entirely unable to solve what should be a very simple  
> problem.  I
> have imported a SPSS dataset into R using spss.get from Frank  
> Harrell's
> Hmisc library.  The variables are imported classed as 'labelled':  
> missing
> values are coded as either the SPSS missing value code, 8 or 88.   
> All are
> imported correctly; 8 and 88 being identified as true numbers in the
> 'summary' command, which treats them (correctly) as numeric. For some
> reason, is.na(x)<-c(8,88) doesn't seem to work. No error message is
> returned, but the 8 and 88 are not set as NA.  The example given in  
> the help
> file does work, so is.na<- is functioning in my copy of R (2.10.1).   
> I've
> tried working outside the dataframe, using unclass, as.numeric, and  
> class<-
> entirely without success.  The variable structure(exemplified by one
> variable) is
>
> Class 'labelled'  atomic [1:827] 2 2 2 2 2 2 8 NA 2 2 ...
>  ..- attr(*, "label")= Named chr "In the last yr, you were unfairly  
> treated
> because of your sex"
>  .. ..- attr(*, "names")= chr "c25a"
>
> All suggestions are gratefully received!
>
> Best wishes
>
> David Foreman
> Consultant and Visiting Professor in Child and Adolescent Psychiatry
>
> 	[[alternative HTML version deleted]]
>
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