>>>>> Rich Shepard >>>>> on Thu, 11 Jun 2020 06:29:13 -0700 writes:
> On Thu, 11 Jun 2020, Martin Maechler wrote: >> > Look at Hadley Wickham's 'tidyverse' collection as > >> described in R for Data Science. There are date, >> datetime, > and time functions that will do just what you >> want. >> I strongly disagree that automatic guessing of date >> format is a good idea: > Martin, > I think either you misunderstood what I wrote or I was not > sufficiently explicit in my brief response. I did not mean > to imply there was any automatic guessing > involved. Specifying input and output formats is required. Well, ok. Yes, then I misunderstood. I know there *are* R packages out there which boast automatically finding the correct format. If you are willing to specify the input format, I don't see why one should use the huge tidyverse instead of just using the potent enough base R functions, one of which Jeff Newmiller was talking about (and to whom you replied saying you'd rather use the extra functions). > Reading Hadley's book I was impressed that one could > specify the format of dates in the dataset and convert > them all to the ISO-8601 format. Before learning this I'd > use emacs regex to do the reformating I needed (or, > sometimes, awk). Well, as you know I use emacs even more than R (because I use R via emacs's ESS), but I think I wouldn't use it to transform dates or date times [well, unless such a date/datetime column is so severely messed up that one format is not appropriate for at least a few large chunks of these] because I'd rather try to use completely reproducible R code from the beginning of cleaning/reading/analysing the raw data to the end. And for that, base R is entirely sufficient in spite of all the advertisements of the many date/time formatting packages. But yes, I wrote more about this about 10 weeks ago on the R-devel list here (which also seemed to have been rather mis-understood, for which I must mostly blame myself of course) : https://stat.ethz.ch/pipermail/r-devel/2020-April/079260.html In that thread, the following 'R News' article was mentioned as good introduction in the subject from a 'base R' (+ "almost recommended" package 'chron') point of view https://www.researchgate.net/publication/229087103_R_Help_Desk_Date_and_time_classes_in_R which is really from here https://www.r-project.org/doc/Rnews/Rnews_2004-1.pdf 'R News' was the predecessor of the R Journal, https://journal.r-project.org/ I think we should leave it here, because we've been diverting too much. Best, Martin ______________________________________________ R-help@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.