[R] Problem with a non-factor, non-numeric variable in a data.frame
Alexandre Santos
alexandre.santos at ochipepe.org
Tue Nov 6 21:56:13 CET 2007
I tested
as.numeric(as.character(Ratio))
and it works perfectly!
I still don't get why as.numeric(Ratio) was not enough, but at least
now I know how to deal with it.
Thanks for the tip, and sorry for missing the R-FAQ issue 7.10.
Cheers,
Alexandre Santos
2007/11/6, John Kane <jrkrideau at yahoo.ca>:
> Have a look at the R-FAQ issue 7.10. It's a standard
> problem
>
> For more information about your variable try
>
> str(variable).
>
>
> --- Alexandre Santos <alexandre.santos at ochipepe.org>
> wrote:
>
> > Dear R list,
> >
> > I would like to perform an ANOVA in a set of
> > measurements, but I have
> > problems formatting the data.
> >
> > The data is a two dimensional array containing two
> > columns:
> > - "Stim" : the type of stimulation (string)
> > - "Ratio" : a ratio of two numeric values
> >
> > Now, because some values are missing in the data
> > (defaulting to zero),
> > part of this array will be populated with NA ratios.
> > Maybe this is
> > important later.
> >
> > In order to make the ANOVA analysis, I need to turn
> > my vector into a data.frame.
> >
> > I tried vector.table=as.data.frame(vector)
> >
> > But I realized that
> > is.numeric(Ratio) gives FALSE
> > is.factor(Ratio) gives TRUE
> >
> > After reading the documentation, I tried
> >
> > vector.table=as.data.frame(vector, stringsAsFactors
> > = FALSE)
> >
> > This time
> >
> > is.numeric(Ratio) gives FALSE
> > is.factor(Ratio) gives FALSE
> >
> > So I don't even know what is Ratio, but it's not yet
> > numeric (is this
> > due to the NA values?).
> >
> > How can I get R to understand that Ratio is numeric?
> > Checking the
> > documentation it seems you can do it with I(x), but
> > the details are
> > not explained. I also tried as.numeric(Ratio), and
> > everything was
> > turned into zeros.
> >
> > Any suggestions?
> >
> > Cheers,
> >
> > Alexandre Santos
> >
> > Neuro-MPI, Martinsread, Germany
> >
> > ______________________________________________
> > R-help at r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide
> > http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained,
> > reproducible code.
> >
>
>
>
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