If you object to names(x)[2]<- ... then use replace:
z |> list(x = _) |> within(replace(names(x), 2, "foo")) |>
_$x
On Sun, Jul 21, 2024 at 11:10?AM Bert Gunter <bgunter.4567 at gmail.com>
wrote:>
> hmmm...
> But note that you still used the nested assignment, names()[2] <-
> "foo", to circumvent R's pipe limitations, which is exactly
what
> Iris's solution avoids. So I think I was overawed by your cleverness
> ;-)
>
> Best,
> Bert
>
>
> On Sun, Jul 21, 2024 at 8:01?AM Bert Gunter <bgunter.4567 at
gmail.com> wrote:
> >
> > Wow!
> > Yes, this is very clever -- way too clever for me -- and meets my
> > criteria for a solution.
> >
> > I think it's also another piece of evidence of why piping in base
R is
> > not suited for complex/nested assignments, as discussed in
Deepayan's
> > response.
> >
> > Maybe someone could offer a better Tidydata piping solution just for
> > completeness?
> >
> > Best,
> > Bert
> >
> > On Sun, Jul 21, 2024 at 7:48?AM Gabor Grothendieck
> > <ggrothendieck at gmail.com> wrote:
> > >
> > > This
> > > - is non-destructive (does not change z)
> > > - passes the renamed z onto further pipe legs
> > > - does not use \(x)...
> > >
> > > It works by boxing z, operating on the boxed version and then
unboxing it.
> > >
> > > z <- data.frame(a = 1:3, b = letters[1:3])
> > > z |> list(x = _) |> within(names(x)[2] <-
"foo") |> _$x
> > > ## a foo
> > > ## 1 1 a
> > > ## 2 2 b
> > > ## 3 3 c
> > >
> > > On Sat, Jul 20, 2024 at 4:07?PM Bert Gunter <bgunter.4567 at
gmail.com> wrote:
> > > >
> > > > This post is likely pretty useless; it is motivated by a
recent post
> > > > from "Val" that was elegantly answered using
Tidyverse constructs, but
> > > > I wondered how to do it using base R only. Along the way, I
ran into
> > > > the following question to which I think my answer (below) is
pretty
> > > > awful. I would be interested in more elegant base R
approaches. So...
> > > >
> > > > z <- data.frame(a = 1:3, b = letters[1:3])
> > > > > z
> > > > a h
> > > > 1 1 a
> > > > 2 2 b
> > > > 3 3 c
> > > >
> > > > Suppose I want to change the name of the second column of z
from 'b'
> > > > to 'foo' . This is very easy using nested function
syntax by:
> > > >
> > > > names(z)[2] <- "foo"
> > > > > z
> > > > a foo
> > > > 1 1 a
> > > > 2 2 b
> > > > 3 3 c
> > > >
> > > > Now suppose I wanted to do this using |> syntax, along
the lines of:
> > > >
> > > > z |> names()[2] <- "foo" ## throws an error
> > > >
> > > > Slightly fancier is:
> > > >
> > > > z |> (\(x)names(x)[2] <- "b")()
> > > > ## does nothing, but does not throw an error.
> > > >
> > > > However, the following, which resulted from a more careful
read of
> > > > ?names works (after changing the name of the second column
back to "b"
> > > > of course):
> > > >
> > > > z |>(\(x) "names<-"(x,value =
"[<-"(names(x),2,'foo')))()
> > > > >z
> > > > a foo
> > > > 1 1 a
> > > > 2 2 b
> > > > 3 3 c
> > > >
> > > > This qualifies to me as "pretty awful." I'm
sure there are better ways
> > > > to do this using pipe syntax, so I would appreciate any
better
> > > > approaches.
> > > >
> > > > Best,
> > > > Bert
> > > >
> > > > ______________________________________________
> > > > R-help at r-project.org mailing list -- To UNSUBSCRIBE and
more, see
> > > > 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.
> > >
> > >
> > >
> > > --
> > > Statistics & Software Consulting
> > > GKX Group, GKX Associates Inc.
> > > tel: 1-877-GKX-GROUP
> > > email: ggrothendieck at gmail.com
--
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