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 <hadley@rice.edu> wrote:

> On Mon, Dec 6, 2010 at 3:58 AM, Sunny Srivastava
> <research.baba@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/
>

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