CODEWITHSUNDEEP
rif-statementconditional-statementstidyverse
deschen
deschen

Reputation: 10996

if_else with sequence of conditions

I have the following data:

library(tidyverse)
library(lubridate)
df <- tibble(date = as_date(c("2019-11-20", "2019-11-27", "2020-04-01", "2020-04-15", "2020-09-23", "2020-11-25", "2021-03-03")))

# A tibble: 7 x 1
  date      
  <date>    
1 2019-11-20
2 2019-11-27
3 2020-04-01
4 2020-04-15
5 2020-09-23
6 2020-11-25
7 2021-03-03

I also have an ordered comparison vector of dates:

comparison <- seq(as_date("2019-12-01"), today(), by = "months") - 1

I now want to compare my dates in df to those comparison dates and so something like:

I know I could do it with a case_when, e.g.

df %>%
  mutate(new_var = case_when(date < comparison[1] ~ 1,
                             date < comparison[2] ~ 2))

(of course filling this up with all comparisons).

However, this would require to manually write out all sequential conditions and I'm wondering if I couldn't just automate it. I though about creating a match lookup first (i.e. take the comparison vector, then add the respective new_var number (i.e. 1, 2, and so on)) and then match it against my data, but I only know how to do that for exact matches and don't know how I can add the "smaller than" condition.

Expected result:

# A tibble: 7 x 2
  date       new_var
  <date>       <dbl>
1 2019-11-20       1
2 2019-11-27       1
3 2020-04-01       6
4 2020-04-15       6
5 2020-09-23      11
6 2020-11-25      13
7 2021-03-03      17

Upvotes: 2

Views: 143

Answers (1)

Erfan Ghasemi
Erfan Ghasemi

Reputation: 417

You can use findInterval as follows:

df %>% mutate(new_var = df$date %>%  findInterval(comparison) + 1)
# A tibble: 7 x 2
  date       new_var
  <date>       <dbl>
1 2019-11-20       1
2 2019-11-27       1
3 2020-04-01       6
4 2020-04-15       6
5 2020-09-23      11
6 2020-11-25      13
7 2021-03-03      17

Upvotes: 1

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