Hi Johannes,

Here are two approaches to accomplish this:

subset(df, select = -B)
df[, colnames(df) != "B"]

HTH,
Jorge.-


On Thu, May 31, 2012 at 10:34 AM, Johannes Radinger <> wrote:

> Hi James
> Hi Jorge,
>
> Thank you very much!
> I like the apply-approach, it seems really quite
> simple and I get back the TRUE-FALSE vector which
> I can use for indexing the dataframe.
> Now there popped the questions if one can implement
> any "exeption", like do the selection of
> the columns exept for column with name "B".
> I have to think about this
>
> /Johannes
>
> -------- Original-Nachricht --------
> > Datum: Thu, 31 May 2012 09:20:27 -0500
> > Von: J Toll <jctoll@gmail.com>
> > An: Johannes Radinger <JRadinger@gmx.at>
> > CC: R-help@r-project.org
> > Betreff: Re: [R] Remove columns from dataframe based on their statistics
>
> > On Thu, May 31, 2012 at 8:52 AM, J Toll <jctoll@gmail.com> wrote:
> >
> > > for (i in seq(ncol(df), 1))
> > >  if (length(unique(df[, i])) == 1) {
> > >  df[, i] <- NULL
> > > }
> >
> > Here's a similar method employing a more functional approach:
> >
> > df[, apply(df, 2, function(x) length(unique(x)) > 1)]
> >
> >
> > James
>
> --
>
> Jetzt informieren: http://mobile.1und1.de/?ac=OM.PW.PW003K20328T7073a
>
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