Assigning categorical values to dates

While the base R solution using 'factor' appears to win based on elegance,
chapeau to the creativity of the other suggestions.
For those who are not aware, R 4.1.0 introduced two features: (1) native
pipe |> and (2) new shorter syntax for anonymous functions.
Erich's suggestion used the native pipe and Rui went with the spirit and
added an anonymous function using the new syntax.

Everyone has their preferred coding style. I tend to prefer fewer lines of
code (if there is no cost in understanding).
I think the new anonymous function syntax helps in this regard and I see
no reason to use piping if not necessary.
So here is a modified, one-line version of Rui's last suggestion (sans the
amazing observation about handling interactions).

mutate(date_df, cycle=(\(ranks) match(dates,
ranks))(sort(unique(dates))))

Eric




On Thu, Jul 22, 2021 at 11:11 AM Uwe Ligges <
ligges at statistik.tu-dortmund.de> wrote:

For a data.frame d, I'd simply do

d$cycle <- factor(d$dates, labels=1:3)

but I have not  idea about tibbles.


Best,
Uwe Ligges


On 22.07.2021 05:12, N. F. Parsons wrote:

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

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