lubridate-选择每周的第一个非星期一。

你可以自己创造一个不断增加的周数。也许不是最优雅的解决方案,但对我来说效果很好。

as_tibble(XLF) %>% 
  rownames_to_column(var = "date")%>% 
  select(date, XLF.Adjusted)%>%
  mutate(date = ymd(date),
         Year = year(date),
         Month = month(date),
         WDay = wday(date),
         WDay_label = wday(date, label = T))%>% 
  # if the weekday number is higher in the line above or 
  # if the date in the previous line is more than 6 days ago
  # the week number should be incremented
  mutate(week_increment  = (WDay < lag(WDay) | difftime(date, lag(date), unit = 'days') > 6))%>%
  # the previous line causes the first element to be NA due to 
  # the fact that the lag function can't find a line above
  # we correct this here by setting the first element to TRUE
  mutate(week_increment = ifelse(row_number() == 1,
                                 TRUE,
                                 week_increment))%>%
  # we can sum the boolean elements in a cumulative way to get a week number
  mutate(week_number = cumsum(week_increment))%>%
  filter(WDay != 2)%>%
  group_by(Year, week_number) %>% 
  filter(row_number() == 1)