[R] Howto access V-base only column in a data frame

Marc Schwartz marc_schwartz at comcast.net
Fri Jun 20 15:01:23 CEST 2008


on 06/19/2008 11:28 PM Rolf Turner wrote:
> 
> On 20/06/2008, at 4:07 PM, Moshe Olshansky wrote:
> 
>> If you know the value of k then you could do the following:
>>
>> goodNames <- paste("V",1:k,sep="")
>> ind <- which(colnames(df) %in% goodNames)
>> df[,ind]
>>
>> (where df is your dataframe).
>>
>> P.S. I won't be surprised if df[,goodNames] is all right too (have not 
>> checked).
> 
> What about df[,grep("^V",names(df))] ?  (Leave off the ``^'' if you want 
> any
> column whose name contains ``V'' (r.t. begins with ``V'').


Unless I missed something in the original request, such that the only 
column to remove is 'var', why not:

   subset(df, select = -var)

?

See ?subset

HTH,

Marc Schwartz



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