split() - unexpected sorting of results

Hi Peter,

2017-10-20 21:33 GMT+02:00 Peter Meissner <retep.meissner at gmail.com>:
Hey,

I found this - for me - quite surprising and puzzling behaviour of split().

split(1:11, as.character(1:11))
split(1:11, 1:11)

When splitting by numerics everything works as expected - sorting of input
== sorting of output -- but when using a character vector everything gets
re-sorted alphabetical.

Although, there are some references in the help files to what happens when
using split, I did not find any note on this - for me - rather unexpected
behaviour.
As the documentation states,

       f: a ?factor? in the sense that ?as.factor(f)? defines the
          grouping, or a list of such factors in which case their
          interaction is used for the grouping.

And, in fact,
as.factor(1:11)
[1] 1  2  3  4  5  6  7  8  9  10 11
Levels: 1 2 3 4 5 6 7 8 9 10 11
as.factor(as.character(1:11))
[1] 1  2  3  4  5  6  7  8  9  10 11
Levels: 1 10 11 2 3 4 5 6 7 8 9

Regards,
I?aki
I would like it best when the sorting of split results stays the same no
matter the input (sorting of input == sorting of output)

If that is not possibly a note of caution in the help pages and maybe an
example might be valuable.

Best, Peter

        [[alternative HTML version deleted]]

______________________________________________
R-devel at r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel

split() - unexpected sorting of results

Thread (6 messages)