R help - Jul 2024 - Using the pipe, |>, syntax with "names<-"

Nope, I still got it wrong: None of my approaches work.  :(

So my query remains: how to do it via piping with |> ?

Bert


On Sat, Jul 20, 2024 at 1:06?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

With further fooling around, I realized that explicitly assigning my
last "solution" 'works'; i.e.

names(z)[2] <- "foo"

can be piped as:

 z <- z |>(\(x) "names<-"(x,value =
"[<-"(names(x),2,'foo')))()
> z
  a foo
1 1   a
2 2   b
3 3   c

This is even awfuller than before. So my query still stands.

-- Bert

On Sat, Jul 20, 2024 at 1:14?PM Bert Gunter <bgunter.4567 at gmail.com>
wrote:
>
> Nope, I still got it wrong: None of my approaches work.  :(
>
> So my query remains: how to do it via piping with |> ?
>
> Bert
>
>
> On Sat, Jul 20, 2024 at 1:06?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