> > I think this behaviour is annoying, because if one does not look
> > carefully enough, one looses the contrasts silently. Hence may I
> suggest
> > to change the code of droplevels to something like the following:
>
> This silently changes the contrasts -- eg, if the first level of the
> facto
On Fri, Oct 21, 2011 at 5:57 AM, Thaler, Thorn, LAUSANNE, Applied
Mathematics wrote:
> Dear all,
>
> Today I figured out that there is a neat function called droplevels,
> which, well, drops unused levels in a data frame. I tried the function
> with some of my data sets and it turned out that not
