定义. roll=-Inf
_ rollends=FALSE
当rollends
未设置或设置为时TRUE
,我看到了预期的结果。我将不胜感激任何建议。
library(data.table)
dt1 = data.table(Date=seq(from=as.Date("2013-01-03"),
to=as.Date("2013-06-27"), by="1 week"),
key="Date")[, ind:=.I]
dt2 = data.table(Date=seq(from=as.Date("2013-01-01"),
to=as.Date("2013-06-30"), by="1 day"),
key="Date")
我希望在下面的输出中看到2013-01-05
并2013-06-26
填充。
dt1[dt2, roll=-Inf, rollends=FALSE]
Date ind
1: 2013-01-01 NA
2: 2013-01-02 NA
3: 2013-01-03 1
4: 2013-01-04 2
5: 2013-01-05 NA
---
177: 2013-06-26 NA
178: 2013-06-27 26
179: 2013-06-28 NA
180: 2013-06-29 NA
181: 2013-06-30 NA
这按预期工作,ind
数据前滚但不在dt1
data.table
.
dt1[dt2, roll=-Inf]
Date ind
1: 2013-01-01 1
2: 2013-01-02 1
3: 2013-01-03 1
4: 2013-01-04 2
5: 2013-01-05 2
---
177: 2013-06-26 26
178: 2013-06-27 26
179: 2013-06-28 NA
180: 2013-06-29 NA
181: 2013-06-30 NA