[Rd] "with" doesn't work with names with blanks

Ben Bolker bbo|ker @end|ng |rom gm@||@com
Sun May 1 23:35:25 CEST 2022


Think trimws() from base R would work too?

On Sun, May 1, 2022, 5:20 PM Spencer Graves <spencer.graves using prodsyse.com>
wrote:

>
>
> On 5/1/22 2:51 PM, Duncan Murdoch wrote:
> > On 01/05/2022 3:41 p.m., Spencer Graves wrote:
> >> Hello, All:
> >>
> >>
> >>       Column names in a data.frame are not supposed to have trailing
> >> blanks.  However, a CRAN package created one, which threw an error with
> >> "with".  Consider the following example:
> >>
> >>
> >>   > (tst <- data.frame(1))
> >>     X1
> >> 1  1
> >>   > names(tst) <- 'x '
> >>   > tst$x
> >> [1] 1
> >>   > with(tst, x)
> >> Error in eval(substitute(expr), data, enclos = parent.frame()) :
>    object 'x' not found>>
> >>
> >>       I think it's interesting that "tst$x" works, but "with(txt, x)".
> >>
> >>
> >>       Comments?
> >
> > tst$x works because of partial name matching.  (That leniency is one of
> > the reasons for advice to avoid using $ in programs.)  It would be chaos
> > if with() used partial name matching.
> >
> > You can use
> >
> > with(txt, `x `)
> >
> > to include the space in the name.
>
>
> but to use that, I have to KNOW that the name is `x `, not `x`.  It took
> me a while to identify that as the source of the problem:  What I saw
> was that "with(tst
>
>
>           And thanks for the reminder that you recommend avoiding use of
> "$".
>
>
>           sg
>
>
> p.s.  After I found the problem, I fixed it using
> names(x) <- tis::stripBlanks(names(x))
>
> >
> > Duncan Murdoch
> >
> >>
> >>
> >>       It's not a major problem, though it took me a while to
> >> diagnose.  (I
> >> reported it to the maintainer of the package that returned a data.frame
> >> with names with trailing blanks.)
> >>
> >>
> >>       Thanks, for all your work in maintaining and upgrading R -- and in
> >> responding to emails from this list.
> >>
> >>
> >>       Spencer Graves
> >>
> >>
> >>   > sessionInfo()
> >> R version 4.2.0 (2022-04-22)
> >> Platform: x86_64-apple-darwin17.0 (64-bit)
> >> Running under: macOS Big Sur 11.6.5
> >>
> >> Matrix products: default
> >> LAPACK:
> >>
> /Library/Frameworks/R.framework/Versions/4.2/Resources/lib/libRlapack.dylib
> >>
> >>
> >> locale:
> >> [1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8
> >>
> >> attached base packages:
> >> [1] stats     graphics  grDevices utils     datasets  methods   base
> >>
> >> loaded via a namespace (and not attached):
> >> [1] compiler_4.2.0 tools_4.2.0
> >>   >
> >>
> >> ______________________________________________
> >> R-devel using r-project.org mailing list
> >> https://stat.ethz.ch/mailman/listinfo/r-devel
> >
>
> ______________________________________________
> R-devel using r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>

	[[alternative HTML version deleted]]



More information about the R-devel mailing list