提取润滑间隔内的月份

Question

给定润滑间隔，例如：

start <- "2016-09-24"
finish <- "2016-11-02"
my_interval <- lubridate::interval(start, finish)
my_interval

> my_interval
[1] 2016-09-24 UTC--2016-11-02 UTC

我希望能够提取属于这个区间的月份，在这种情况下：

[1] "Sep" "Oct" "Nov"

到目前为止，我在这方面的最佳尝试真的很笨拙：

my_months <- list(
  "Aug" = interval("2016-08-01", "2016-08-31"), 
  "Sep" = interval("2016-09-01", "2016-09-30"), 
  "Oct" = interval("2016-10-01", "2016-10-31"), 
  "Nov" = interval("2016-11-01", "2016-11-30"), 
  "Dec" = interval("2016-12-01", "2016-12-31")
)

extract_months <- function(x, months) {
  out <- vector(mode = "character")

  for (i in seq_along(months)) {
    in_month <- int_overlaps(x, months[[i]])
    if (in_month) {
      out[i] <- names(months)[i]
    }
    out <- out[!is.na(out)]
  }
  out
}

extract_months(x = my_interval, months = my_months)

> extract_months(x = my_interval, months = my_months)
[1] "Sep" "Oct" "Nov"

多年来，这很快变得笨拙。我希望有人有更好的解决方案。

我看不出这个问题与

的重复

Answer 1

其实很简单！

library(lubridate)
month.abb[month(start):month(finish)]

如果这不起作用，请告诉我。

Answer 2

@Kim 解决方案的问题是，如果时间间隔超过 1 年，它将不再有效：

library(lubridate)
# works:
month.abb[month("2016-09-24"):month("2016-11-02")]
[1] "Sep" "Oct" "Nov"
# wrong (should be Sep, Oct, Nov, Dec, Jan):
month.abb[month("2016-09-24"):month("2017-01-02")]
[1] "Sep" "Aug" "Jul" "Jun" "May" "Apr" "Mar" "Feb" "Jan"

一个解决方案可能是：

# correct:
month.abb[unique(month(seq.Date(from = as.Date("2016-09-24"), to = as.Date("2017-01-02"), by = "day")))]
[1] "Sep" "Oct" "Nov" "Dec" "Jan"

Answer 3

进一步可能包括年份：

library(lubridate)

# the next 12 months starting on the first of next month
my_interval = interval(ceiling_date(Sys.Date(),unit = "month"),
ceiling_date(Sys.Date(),unit = "month") + years(1) - days(1))

year_month_vec <- paste0(year(seq.Date(from = date(int_start(my_interval)),to = date(int_end(my_interval)),by = "month")),"-",
  month.abb[month(seq.Date(from = date(int_start(my_interval)),to = date(int_end(my_interval)),by = "month"))])

提取润滑间隔内的月份

Extract the months that fall in a lubridate interval

r

lubridate