I have a dataset and I'm trying to find the closet date to '2021-08-02' without going before it. So, in my sample dataset below, I want it to filter out everything before '2021-08-05' since that is the nearest date without going sooner.
library(dplyr)
test <- tibble(Day = seq(as.Date("2021-08-01"), as.Date("2021-09-10"), by="4 days"),
Score = c(sample(1:15, 11)))
Get the absolute difference between them, find the minimum index, and return the sequence
library(dplyr)
date <- as.Date('2021-08-02')
test %>%
slice(seq_len(which.min(abs(date - Day))))
-output
# A tibble: 1 × 2
Day Score
<date> <int>
1 2021-08-01 11
If we want to return the other set of rows, either use %>% anti_join(df, .) after the slice step or create a condition with row_number()
test %>%
filter(row_number() > seq_len(which.min(abs(date - Day))))
# A tibble: 10 × 2
Day Score
<date> <int>
1 2021-08-05 9
2 2021-08-09 12
3 2021-08-13 13
4 2021-08-17 6
5 2021-08-21 4
6 2021-08-25 1
7 2021-08-29 10
8 2021-09-02 3
9 2021-09-06 7
10 2021-09-10 8