[R] Adding SORT to UNIQUE

[Bert Gunter]

Martin:

I think the issue is this:
> sort(c('a10','a1','a3'))
[1] "a1"  "a10" "a3"
> ## wanted 'a1', 'a3', 'a10' ??

The OP would have to confirm, of course. If he only wanted to sort
just numerics, coercing to numeric first would presumably handle it.
For situations like the above, one probably needs a custom strategy to
define the ordering, right?

Cheers,
Bert


On Mon, Dec 20, 2021 at 9:32 AM Martin Maechler
<maechler using stat.math.ethz.ch> wrote:
>
> >>>>> Rui Barradas
> >>>>>     on Mon, 20 Dec 2021 17:05:33 +0000 writes:
>
>     > Hello,
>     > Package stringr has functions str_sort and str_order, both with an
>     > argument 'numeric' that will sort the numbers correctly.
>     > Maybe that's what you are looking for, see the example below.
>
>
>     > x <- sample(sprintf("ab%d", 1:20))     # shuffle the vector
>     > stringr::str_sort(x, numeric = TRUE)   # sort considering the numbers
>
> Again:
> There's really no need to use non-base R here (and in almost all
> such questions about string handling!)
> as Avi Gross' answer shows.
>
>
>     > Hope this helps,
>
>     > Rui Barradas
>
>
>     > Às 16:58 de 20/12/21, Stephen H. Dawson, DSL via R-help escreveu:
>     >> Hi,
>     >>
>     >>
>     >> Running a simple syntax set to review entries in dataframe columns. Here
>     >> is the working code.
>     >>
>     >> Data <- read.csv("./input/Source.csv", header=T)
>     >> describe(Data)
>     >> summary(Data)
>     >> unique(Data[1])
>     >> unique(Data[2])
>     >> unique(Data[3])
>     >> unique(Data[4])
>     >>
>     >> I would like to add sort the unique entries. The data in the various
>     >> columns are not defined as numbers, but also text. I realize 1 and 10
>     >> will not sort properly, as the column is not defined as a number, but
>     >> want to see what I have in the columns viewed as sorted.
>     >>
>     >> QUESTION
>     >> What is the best process to sort unique output, please?
>     >>
>     >>
>     >> Thanks.
>
>     > ______________________________________________
>     > R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
>     > https://stat.ethz.ch/mailman/listinfo/r-help
>     > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>     > and provide commented, minimal, self-contained, reproducible code.
>
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.