[R] level sets of factors are different

[Richard van Wingerden]

Thanks!

The as.character fixed it!

Regards,
Richard

On 1/7/06, Prof Brian Ripley <ripley at stats.ox.ac.uk> wrote:
> The message is really explicit.
>
> You are trying to compare the equality of two factors with different level
> sets.  Such factors are not comparable (and this is discussed on ?factor).
> You didn't give a reproducible example, and you have not told us what you
> are trying to do, so all we can do is repeat R's report that what you
> actually did is not sensible.
>
> On Sat, 7 Jan 2006, Richard van Wingerden wrote:
>
> > Hi,
> >
> > I have two data frames A en B.
> > I want to filter B with values of A
> >
> > data_frame_b
> > names <- colnames(data_frame_b[1:1, ])
> >
> > filtera <- data.frame(data_frame_a[1:1])
>
> This is bit strange. data_frame_a[1:1] is data_frame_a[1] and is a
> single-column data-frame.  I think you might just as well use
>
> filtera <- data_frame_a[[1]]
>
> which is (probably) a factor.  You then seem to want to extract values
> equal to its first element, so maybe you actually wanted
> columnX == as.character(data_frame_a[1,1]) ?
>
> >
> >       print(nrow(filtera))
> >
> >       if (nrow(filtera)>0){
> >
> >               filtered_frame_b <- subset(data_frame_b, ColumnX == filtera[1, 1], names)
> >         }
> > The results are:
> >
> > [1] 124
> > Error in Ops.factor(ColumnX, filtera[1, 1]) :
> >        level sets of factors are different
> >
> >
> > What is wrong??
> >
> > Richard
>
>
> --
> Brian D. Ripley,                  ripley at stats.ox.ac.uk
> Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
> University of Oxford,             Tel:  +44 1865 272861 (self)
> 1 South Parks Road,                     +44 1865 272866 (PA)
> Oxford OX1 3TG, UK                Fax:  +44 1865 272595
>