R XTS to.weekly返回不同的每周端点

我遇到一个问题，

xts

中的

endpoints（）

函数（以及使用端点的

to.weekly

函数）有时返回星期五作为周末，有时返回星期一

我的数据集称为

sp2

> head(sp2)
           [,1]
2012-01-09 1.78
2012-01-10 1.78
2012-01-11 1.77
2012-01-12 1.80
2012-01-13 1.77
2012-01-16 1.77

> tail(sp2)
           [,1]
2012-06-28 1.94
2012-06-29 1.92
2012-07-02 1.92
2012-07-03 1.90
2012-07-04 1.89
2012-07-05 1.89

> class(sp2)
[1] "xts" "zoo"

> weekdays(index(sp2))
  [1] "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"    "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"   
 [11] "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"    "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"   
 [21] "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"    "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"   
 [31] "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"    "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"   
 [41] "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"    "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"   
 [51] "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"    "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"   
 [61] "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"    "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"   
 [71] "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"    "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"   
 [81] "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"    "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"   
 [91] "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"    "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"   
[101] "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"    "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"   
[111] "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"    "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"   
[121] "Monday"    "Tuesday"   "Wednesday" "Thursday"  "Friday"    "Monday"    "Tuesday"   "Wednesday" "Thursday" 

因此，正如您所看到的，数据系列中没有缺少工作日

然而

> weekdays(index(to.weekly(sp2)))
 [1] "Friday"   "Friday"   "Friday"   "Friday"   "Friday"   "Friday"   "Friday"   "Friday"   "Friday"   "Friday"   "Monday"  
[12] "Monday"   "Monday"   "Monday"   "Monday"   "Monday"   "Monday"   "Monday"   "Monday"   "Monday"   "Monday"   "Monday"  
[23] "Monday"   "Monday"   "Monday"   "Thursday"

当然，这应该一直是星期五（除了今天的最后一点，星期四）

我做错了什么，有解决办法吗

我希望计算这个数据系列从周五到周五的每周变化

可复制示例

i <- as.Date((as.numeric(Sys.Date())-200):as.numeric(Sys.Date()))
x <- xts(rep(1, length(i)), order.by = i)
weekdays(index(to.weekly(x)))
#  [1] "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"  
# [14] "Sunday"   "Monday"   "Monday"   "Monday"   "Monday"   "Monday"   "Monday"   "Monday"   "Monday"   "Monday"   "Monday"   "Monday"   "Monday"  
# [27] "Monday"   "Monday"   "Monday"   "Thursday"
y <- xts(rep(1, length(i)), order.by = as.POSIXct(i))
weekdays(index(to.weekly(y)))
# [1] "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"  
# [14] "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"   "Sunday"  
# [27] "Sunday"   "Sunday"   "Sunday"   "Thursday"

---

i这是CRAN版本中的一个bug，已在R-Forge上修复。基本上，索引中的时间部分并没有被删除，你在时区和夏令时方面遇到了一些麻烦

使用已更正的功能

require(xts)
i <- Sys.Date()+200:0
x <- xts(rep(1, length(i)), order.by = i)
y <- xts(rep(1, length(i)), order.by = as.POSIXct(i))
all.equal(weekdays(index(to.weekly(x))), weekdays(index(to.weekly(y))))

require（xts）
我知道您使用的是什么版本的xts？我刚刚升级到R2.15.1并运行了更新。packages（）。显示“0.8-2”。哦，我看到我们在0.8-6。更新（是/否/否）？y警告：软件包“xts”、“zoo”正在使用中，不会安装，这可能是问题所在。让我来解决它…如果问题在更新后仍然存在，你能举个例子吗？我找到了解决方案。我的日期索引数据（来自彭博社）是“日期”格式的。将其更改为POSIXct解决了这个问题。