Question

给定一个随机的开始和结束日期，我如何创建一个新的序列（或修改这个序列）从第一个星期一开始到最后一个星期五结束？

MyDays <- seq(StartDate , EndDate , by = "day")
SequenceDay <- days [!is.weekend(MyDays)]

谢谢！

Answer 1

与Tony Breyal的回答相似。请注意，只有当您的系统在一周中的某几天使用英语拼写时，这些才有效。

StartDate <- as.Date("2010-01-01")
EndDate <- as.Date("2010-12-31")
myDays <- seq(StartDate , EndDate, by = "day") 
excludeDays <- c("Saturday", "Sunday")
myWeekDays <- subset(myDays, !weekdays(myDays) %in% excludeDays)
firstMonday <- which(weekdays(head(myWeekDays, 5)) == "Monday")
lastFriday <- length(myWeekDays) - 5 + 
              which(weekdays(tail(myWeekDays, 5)) == "Friday")
myCompleteWeeks <- myWeekDays[firstMonday:lastFriday]

Answer 2

POSIXlt为您提供与语言无关的方式。 match()和rev()比较容易一些。 chron包中包含函数is.weekend()。使用温彻斯特的矢量myDays：

myDays <- as.POSIXlt(myDays)
wdays <- myDays$wday
n <- length(myDays)+1

myDays <- myDays[match(1,wdays):(n-match(5,rev(wdays)))]

要排除周末，您可以使用chron库

library(chron)
myDays[!is.weekend(myDays)]

这适用于POSIXt，Date和chron对象，因此您可以独立于其他代码使用它。使用POSIXlt，您也可以再次使用％in％：

myDays[! myDays$wday %in% c(0,6)]

Answer 3

假设我理解正确（'目前是工作日的结束而我在酒吧），那么这个怎么样：

# set start and end dates
n <- 31
d.start <- Sys.Date()
d.end <- d.start + n

# workhorse code
my.seq = seq(d.start, d.end, "days")
x1 <- weekdays(my.seq)
first.Mon <- which(x1=="Monday")[1]
last.friday <- which(x1=="Friday")[length(which(x1=="Friday"))]
x <- my.seq[first.Mon:last.Fri]
ind.sats <- which(weekdays(x) == "Saturday")
ind.suns <- which(weekdays(x) == "Sunday")
x <- x[-c(ind.sats, ind.suns)]

哪个应该给你：

> x
 [1] "2011-03-07" "2011-03-08" "2011-03-09" "2011-03-10" "2011-03-11"
 [6] "2011-03-14" "2011-03-15" "2011-03-16" "2011-03-17" "2011-03-18"
[11] "2011-03-21" "2011-03-22" "2011-03-23" "2011-03-24" "2011-03-25"
[16] "2011-03-28" "2011-03-29" "2011-03-30" "2011-03-31" "2011-04-01"

或

> weekdays(x)
 [1] "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"    "Monday"   
 [7] "Tuesday"   "Wednesday" "Thursday"  "Friday"    "Monday"    "Tuesday"  
[13] "Wednesday" "Thursday"  "Friday"    "Monday"    "Tuesday"   "Wednesday"
[19] "Thursday"  "Friday"

取决于你想要的是什么。无论如何，这是基本的想法，你可能需要添加一些错误检查。

周一开始，周五结束

3 个答案: