我有以下时间序列
> y<- xts(1:10, Sys.Date()+1:10)
> y[c(1,2,5,9,10)] <- NA
> y
[,1]
2011-09-04 NA
2011-09-05 NA
2011-09-06 3
2011-09-07 4
2011-09-08 NA
2011-09-09 6
2011-09-10 7
2011-09-11 8
2011-09-12 NA
2011-09-13 NA
直接的na.locf给我这个:
> na.locf(y)
[,1]
2011-09-04 NA
2011-09-05 NA
2011-09-06 3
2011-09-07 4
2011-09-08 4
2011-09-09 6
2011-09-10 7
2011-09-11 8
2011-09-12 8
2011-09-13 8
我怎么做到这一点?
[,1]
2011-09-04 NA
2011-09-05 NA
2011-09-06 3
2011-09-07 4
2011-09-08 4
2011-09-09 6
2011-09-10 7
2011-09-11 8
2011-09-12 NA
2011-09-13 NA
我不希望最后一次观察结果除了最后一次非缺失值之外,即不会替换尾随的NA。非常感谢你的帮助!
答案 0 :(得分:7)
使用zoo包中的na.approx
(由xts自动加载):
na.approx(y, method = "constant", na.rm = FALSE)