Thank you for the help. Much appreciated.
On Mon, Dec 6, 2010 at 9:12 PM, Hadley Wickham <had...@rice.edu> wrote:
> It's easiest to see what's going on if you use eval.quoted directly:
>
> eval.quoted(.(cyl), mtcars)
> eval.quoted(.("cyl"), mtcars)
> eval.quoted(.(as.name("cyl")), mtcars)
>
> But you shouldn't need to do any syntactic hackery because the default
> method automatically parses the string for you:
>
> eval.quoted(as.quoted("cyl"), mtcars)
>
> Hadley
>
> On Mon, Dec 6, 2010 at 6:22 PM, Sunny Srivastava
> <research.b...@gmail.com> wrote:
> > Hi Hadley:
> > I was trying to use ddply using the format . (var1) for splitting.
> > I thought . ( as.name(grp) ) would do the same thing. But it does not. I
> was
> > just trying to know my mistake. I am sorry if it is a basic question.
> > Thank you and others for your reply.
> > Best Regards,
> > S.
> >
> > On Mon, Dec 6, 2010 at 5:28 PM, Hadley Wickham <had...@rice.edu> wrote:
> >>
> >> On Mon, Dec 6, 2010 at 3:58 AM, Sunny Srivastava
> >> <research.b...@gmail.com> wrote:
> >> > Dear R-Helpers:
> >> >
> >> > I am using trying to use *ddply* to extract min and max of a
> particular
> >> > column in a data.frame. I am using two different forms of the
> function:
> >> >
> >> >
> >> > ## var_name_to_split is a string -- something like "var1" which is the
> >> > name
> >> > of a column in data.frame
> >> >
> >> > ddply( df, .(as.name(var_name_to_split)), function(x) c(min(x[ , 3] ,
> >> > max(x[
> >> > , 3]))) ## fails with an error - case 1
> >> > ddply( df, var_name_to_split , function(x) c(min(x[ , 3] , max(x[ ,
> >> > 3])))
> >> > ## works fine - case 2
> >> >
> >> > I can't understand why I get the error in case 1. Can someone help me
> >> > please?
> >>
> >> Why do you expect case 1 to work?
> >>
> >> Hadley
> >>
> >> --
> >> Assistant Professor / Dobelman Family Junior Chair
> >> Department of Statistics / Rice University
> >> http://had.co.nz/
> >
> >
>
>
>
> --
> Assistant Professor / Dobelman Family Junior Chair
> Department of Statistics / Rice University
> http://had.co.nz/
>
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