计算从事件到 R 中另一个事件的天数

Question

data.frame(
  scrape_date = as.Date(c("2023-01-01", "2023-01-02", "2023-01-03", "2023-01-04", "2023-01-05", "2023-01-06", "2023-01-07", "2023-01-08")),
  own_product_id = c("00617","00617","00617","00617","00617","00617","00617","00617"),
  own_price = c(70, 70, 70, 70, 70,70,70,71),
  comp_price = c(70, 71, 71, 71, 71,71,71,71)
)

如果我想计算从 comp_price 变化到 own_price 相同需要多少天？我该怎么做呢？抱歉，这让我很头疼

期待类似的输出

product_id   time_taken_to_match
00617          6 days 

Answer 1

您可以使用

cumsum()

来确定

own_price

何时赶上

comp_price

。

library(dplyr)

df %>%
  group_by(own_product_id, grp = cumsum(own_price == comp_price)) %>% 
  summarise(time_taken_to_match = diff(range(scrape_date)), .groups = "drop") %>%
  filter(time_taken_to_match > 0)

# # A tibble: 1 × 3
#   own_product_id   grp time_taken_to_match
#   <chr>          <int> <drtn>             
# 1 00617              1 6 days