R devel - Jun 2025 - Suggestion: Modify common hypothesis tests and models to work better with pipes

To use functions for common statistical tests/models, like t.test,
wilcox.test, lm, glm, and aov, we must currently use the pipe placeholder _
when using pipes:

penguins |>
    subset(species != "Gentoo") |>
    t.test(bill_len ~ species, data = _)

The syntax would be cleaner and perhaps more intuitive if we didn't have to
add the `data = _` bit:

penguins |>
    subset(species != "Gentoo") |>
    t.test(bill_len ~ species)

I believe that this is how t.test and the other functions I mentioned would
have worked if they'd been written after the base pipe was introduced.

Currently, t.test and friends only accept a vector and/or a formula as
their first argument. Since there already is a formula method for these
functions, a simple way to make the second example above work would be to
define a data.frame method like so:

t.test.data.frame <- function(x, formula, ...)
{
    t.test.formula(formula, x, ...)
}

...perhaps with a check to make sure that the formula argument actually is
a formula.

Now, this seems like an easy thing to fix, and it doesn't break any
existing functionality of these functions. Since the base pipe was
introduced four years ago, I suspect that there might be some reason why
this hasn't been implemented already, and I'm curious to find out what
that
is. Or, if there is support for the idea above, I'd be happy to submit a
feature request in Bugzilla and provide code for implementing this.

Best regards,
M?ns

	[[alternative HTML version deleted]]

I am not saying this is wonderful but this does work:

  penguins |>
      subset(species != "Gentoo") |>
      stats:::t.test.formula(formula = bill_len ~ species)

Also there is a problem with t.test in that methods are not supposed
to have conflicting
signatures but

  > args(t.test)
  function (x, ...)
  NULL

  > args(stats:::t.test.formula)
  function (formula, data, subset, na.action = na.pass, ...)
  NULL

On Tue, Jun 10, 2025 at 6:39?AM M?ns Thulin <gausseliminering at
gmail.com> wrote:
>
> To use functions for common statistical tests/models, like t.test,
> wilcox.test, lm, glm, and aov, we must currently use the pipe placeholder _
> when using pipes:
>
> penguins |>
>     subset(species != "Gentoo") |>
>     t.test(bill_len ~ species, data = _)
>
> The syntax would be cleaner and perhaps more intuitive if we didn't
have to
> add the `data = _` bit:
>
> penguins |>
>     subset(species != "Gentoo") |>
>     t.test(bill_len ~ species)
>
> I believe that this is how t.test and the other functions I mentioned would
> have worked if they'd been written after the base pipe was introduced.
>
> Currently, t.test and friends only accept a vector and/or a formula as
> their first argument. Since there already is a formula method for these
> functions, a simple way to make the second example above work would be to
> define a data.frame method like so:
>
> t.test.data.frame <- function(x, formula, ...)
> {
>     t.test.formula(formula, x, ...)
> }
>
> ...perhaps with a check to make sure that the formula argument actually is
> a formula.
>
> Now, this seems like an easy thing to fix, and it doesn't break any
> existing functionality of these functions. Since the base pipe was
> introduced four years ago, I suspect that there might be some reason why
> this hasn't been implemented already, and I'm curious to find out
what that
> is. Or, if there is support for the idea above, I'd be happy to submit
a
> feature request in Bugzilla and provide code for implementing this.
>
> Best regards,
> M?ns
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel


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