[R] row.names are dropped when extracting one column ?

[Marc Schwartz]

On Tue, 2004-03-02 at 11:59, ryszard.czerminski at pharma.novartis.com
wrote:
> Apparently row names are dropped when I extract
> single column from a data frame. Why this behaviour ?
> 
> > y <- as.matrix(df[,1:2]); length(row.names(y))
> [1] 324
> > y <- as.matrix(df[,1:1]); length(row.names(y))
> [1] 0
> 
> Best regards,
> 
> Ryszard


Please see R-FAQ 7.7:

"Why do my matrices lose dimensions?"

HTH,

Marc Schwartz