19.5.3 Rolling joins

[hanguojun007]

Hi , I think this picture is wrong.
https://r4ds.hadley.nz/joins#fig-join-closest
this is example code:

library(dplyr)

# 示例数据
df1 <- tibble(
  time1 = c(1, 2, 3),
  value1 = c("A", "B", "C")
)

df2 <- tibble(
  time2 = c(1, 2, 4),
  value2 = c("X", "Y", "Z")
)
df1 %>%
  left_join(df2, by = join_by(closest(time1 <= time2)))

result is

# A tibble: 3 × 4
  time1 value1 time2 value2
  <dbl> <chr>  <dbl> <chr> 
1     1 A          1 X
2     2 B          2 Y     
3     3 C          4 Z