# [R] Assigning categorical values to dates

N. F. Parsons n@th@n@|@p@r@on@ @end|ng |rom gm@||@com
Thu Jul 22 08:58:24 CEST 2021

```I had no idea that ‘cur_group_id()’ existed!?!! Will definitely try that. Thank you!!!

—
Nathan Parsons, B.SC, M.Sc, G.C.

Ph.D. Candidate, Dept. of Sociology, Portland State University
Adjunct Professor, Dept. of Sociology, Washington State University

Recent work (https://www.researchgate.net/profile/Nathan_Parsons3/publications)
Schedule an appointment (https://calendly.com/nate-parsons)

> On Wednesday, Jul 21, 2021 at 11:54 PM, Rui Barradas <ruipbarradas using sapo.pt (mailto:ruipbarradas using sapo.pt)> wrote:
> Hello,
>
> Here are 3 solutions, one of them the coercion to factor one.
> Since you are using tibbles, I assume you also want a dplyr solution.
>
>
> library(dplyr)
>
> df1 <- tibble(dates = c(rep("2021-07-04", 2),
> rep("2021-07-25", 3),
> rep("2021-07-18", 4)))
>
> # base R
> as.integer(factor(df1\$dates))
> match(df1\$dates, unique(sort(df1\$dates)))
>
> # dplyr
> df1 %>% group_by(dates) %>% mutate(cycle = cur_group_id())
>
>
> My favorite is by far the 1st but that's a matter of opinion.
>
>
> Hope this helps,
>
>
>
> Às 04:46 de 22/07/21, N. F. Parsons escreveu:
> > I am not averse to a factor-based solution, but I would still have to manually enter that factor each month, correct? If possible, I’d just like to point R at that column and have it do the work.
> >
> > —
> > Nathan Parsons, B.SC, M.Sc, G.C.
> >
> > Ph.D. Candidate, Dept. of Sociology, Portland State University
> > Adjunct Professor, Dept. of Sociology, Washington State University
> >
> > Recent work (https://www.researchgate.net/profile/Nathan_Parsons3/publications)
> > Schedule an appointment (https://calendly.com/nate-parsons)
> >
> > > On Wednesday, Jul 21, 2021 at 8:30 PM, Tom Woolman <twoolman using ontargettek.com (mailto:twoolman using ontargettek.com)> wrote:
> > >
> > > Couldn't you convert the date columns to character type data in a data
> > > frame, and then convert those strings to factors in a 2nd step?
> > >
> > > The only downside I think to treating dates as factor levels is that
> > > you might have an awful lot of factors if you have a large enough
> > > dataset.
> > >
> > >
> > >
> > > Quoting "N. F. Parsons" <nathan.f.parsons using gmail.com>:
> > >
> > > > Hi all,
> > > >
> > > > If I have a tibble as follows:
> > > >
> > > > tibble(dates = c(rep("2021-07-04", 2), rep("2021-07-25", 3),
> > > > rep("2021-07-18", 4)))
> > > >
> > > > how in the world do I add a column that evaluates each of those dates and
> > > > assigns it a categorical value such that
> > > >
> > > > dates cycle
> > > > <chr> <chr>
> > > > 2021-07-04 1
> > > > 2021-07-04 1
> > > > 2021-07-25 3
> > > > 2021-07-25 3
> > > > 2021-07-25 3
> > > > 2021-07-18 2
> > > > 2021-07-18 2
> > > > 2021-07-18 2
> > > > 2021-07-18 2
> > > >
> > > > Not to further complicate matters, but some months I may only have one
> > > > date, and some months I will have 4 dates - so thats not a fixed quantity.
> > > > We've literally been doing this by hand at my job and I'd like to automate
> > > > it.
> > > >
> > > > Thanks in advance!
> > > >
> > > > Nate Parsons
> > > >
> > > > [[alternative HTML version deleted]]
> > > >
> > > > ______________________________________________
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> > > ______________________________________________
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> > > and provide commented, minimal, self-contained, reproducible code.
> >
> > [[alternative HTML version deleted]]
> >
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