[R] how to rename variables by lopping off first 3 characters

[Jeff Newmiller]

If the phrase "some of the variable names begin with" actually turns out to be a sloppy version of "the first column name begins with", then the best solution is probably to specify fileEncoding="UTF-8-BOM" as an argument to read.csv before trying all this fix-after-the-fact work. This will also handle other non-ASCII characters properly if they are present.

On March 14, 2022 10:52:49 AM PDT, Rui Barradas <ruipbarradas using sapo.pt> wrote:
>Hello,
>
>I have already seen those names starting with 'i..' several times but I 
>don't remember where nor why.
>I think it has to do with encoding. Or maybe special characters. I have 
>the impression that the best solution was to read the data in a way as 
>to avoid the problem.
>
>Using Bert's example data set, here are base R and tidyverse solutions.
>
>
>dat <- data.frame(
>   i..One = 1:3,
>   i..Two = letters[1:3],
>   ixx = 5:7)
>
># base R
>names(dat) <- sub("^i\\.\\.", "", names(dat))
>names(dat)
>
># tidyverse
>dplyr::rename_with(dat, .fn = \(x) sub("^i\\.\\.", "", x), 
>starts_with("i.."))
>
>
>Hope this helps,
>
>Rui Barradas
>
>Às 16:26 de 14/03/2022, Christopher W Ryan via R-help escreveu:
>> I have data coming to me from another source, in which some of the variable
>> names begin with "i.."
>> 
>> As in "i..actual_meaningful_var_name"
>> 
>> I would like to remove the first three characters from any variable name if
>> they are "i.."
>> 
>> I'm using R on Win 10 and dplyr, so ideally I'm looking for a dplyr
>> solution. Apparently I'm just not understanding how the various select,
>> contains, rename_at, rename_with, and so-on dplyr expressions work. I've
>> tried various arrangements of them, usually resulting in
>> 
>> Error: `contains()` must be used within a *selecting* function.
>> i See <https://tidyselect.r-lib.org/reference/faq-selection-context.html>
>> 
>> A simple select(contains(foo)) I can do fine, to select a subset of
>> variables. It's combining it with renaming that I am struggling with.
>> 
>> Grateful for any advice.
>> 
>> Thanks.
>> 
>> --Chris Ryan
>> 
>> 	[[alternative HTML version deleted]]
>> 
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>
>______________________________________________
>R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
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>and provide commented, minimal, self-contained, reproducible code.

-- 
Sent from my phone. Please excuse my brevity.