[Rd] "with" doesn't work with names with blanks
Spencer Graves
@pencer@gr@ve@ @end|ng |rom prod@y@e@com
Sun May 1 23:19:32 CEST 2022
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
>> >
>>
>> ______________________________________________
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>> https://stat.ethz.ch/mailman/listinfo/r-devel
>
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