# Re: [R] a question of substitute

From: Gabor Grothendieck <ggrothendieck_at_gmail.com>
Date: Wed 10 Jan 2007 - 17:03:22 GMT

Paste the code in this file:

into your session. Then fun.2 from your post will work without the workarounds I posted:

fun.2(values ~ group)

> On Tuesday 09 January 2007 15:14, Gabor Grothendieck wrote:
> > oneway.test is using substitute on its arguments so its literally
> > getting formula rather than the value of formula.
>
> Ah-haa... I understand now. Thanks for the tips, they both work as expected.
> Best,
>
> > Try these:
> >
> > fun.3 <- function(formula) {
> > mc <- match.call()
> > mc[[1]] <- as.name("oneway.test")
> > eval.parent(mc)
> > }
> > fun.3(values ~ group)
> >
> > fun.4 <- function(formula) {
> > do.call(oneway.test, list(formula))
> > }
> > fun.4(values ~ group)
> >
> > On 1/9/07, Adrian Dusa <dusa.adrian@gmail.com> wrote:
> > > Hi all,
> > >
> > > I want to write a wrapper for an analysis of variance and I face a
> > > curious problem. Here are two different wrappers:
> > >
> > > fun.1 <- function(formula) {
> > > summary(aov(formula))
> > > }
> > >
> > > fun.2 <- function(formula) {
> > > oneway.test(formula)
> > > }
> > >
> > > values <- c(15, 8, 17, 7, 26, 12, 8, 11, 16, 9, 16,
> > > 24, 20, 19, 9, 17, 11, 8, 15, 6, 14)
> > > group <- rep(1:3, each=7)
> > >
> > > # While the first wrapper works just fine:
> > > fun.1(values ~ group)
> > >
> > > # the second throws an error:
> > > fun.2(values ~ group)
> > > Error in substitute(formula)[[2]] : object is not subsettable
> > >
> > > ###
> > >
> > > I also tried binding the two vectors in a data.frame, with no avail.
> > > I did find a hack, creating two new vectors inside the function and
> > > creating a fresh formula, so I presume this has something to do with
> > > environments.
> > >
> > > Could anybody give me a hint on this?
> > > Thank you,
> > > Adrian
> > >
> > > --
> > > Adrian Dusa
> > > Romanian Social Data Archive
> > > 1, Schitu Magureanu Bd
> > > 050025 Bucharest sector 5
> > > Romania
> > > Tel./Fax: +40 21 3126618 \
> > > +40 21 3120210 / int.101
> > >
> > > ______________________________________________
> > > R-help@stat.math.ethz.ch 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.
>
> --
> Arhiva Romana de Date Sociale
> Bd. Schitu Magureanu nr.1
> 050025 Bucuresti sectorul 5
> Romania
> Tel./Fax: +40 21 3126618 \
> +40 21 3120210 / int.101
>

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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. Received on Thu Jan 11 04:13:01 2007

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