我想创建一个标记值是否是该月的最后一天的列。考虑我的初始数据表和代码：
Date Companyvar variable value DOW Month EndOfMonth
1: 1992-07-31 VAHXRI MV NA Friday Jul 0
2: 1992-07-31 VAHXTD MV NA Friday Jul 0
3: 1992-07-31 VAHXND MV NA Friday Jul 0
4: 1992-07-31 ASXMV MV NA Friday Jul 0
5: 1992-07-31 ASXRI MV NA Friday Jul 1
6: 1992-08-03 AIZXMV MV NA Monday Aug 0
7: 1992-08-03 AIZXRI MV NA Monday Aug 0
8: 1992-08-03 AIZXTD MV NA Monday Aug 0
9: 1992-08-03 AIZXND MV NA Monday Aug 0
10: 1992-08-03 AQZXMV MV NA Monday Aug 0
sapply(trans, class)
Date Companyvar variable value DOW Month EndOfMonth
"Date" "factor" "factor" "numeric" "character" "character" "numeric"
我创造了＆＃34; EndOfMonth＆＃34;专栏：
trans <- trans[, EndOfMonth := ifelse(shift(Month, type = "lead", n = 1) != Month, 1, 0)]
但是，正如您所看到的，我在7月31日有多个日期，但只有最后一个被标记为＆＃34; EndOfMonth＆＃34;。据我所知，我的代码仅在Month列中有变化时才会查找，根据定义，它只会从7月到8月进行单一变化。
我想知道是否有办法让7月31日的所有5个日期都被标记为＆＃34; EndOfMonth＆＃34;而不仅仅是最后一个。
即所需的输出是：
Date Companyvar variable value DOW Month EndOfMonth
1: 1992-07-31 VAHXRI MV NA Friday Jul 1
2: 1992-07-31 VAHXTD MV NA Friday Jul 1
3: 1992-07-31 VAHXND MV NA Friday Jul 1
4: 1992-07-31 ASXMV MV NA Friday Jul 1
5: 1992-07-31 ASXRI MV NA Friday Jul 1
6: 1992-08-03 AIZXMV MV NA Monday Aug 0
7: 1992-08-03 AIZXRI MV NA Monday Aug 0
8: 1992-08-03 AIZXTD MV NA Monday Aug 0
9: 1992-08-03 AIZXND MV NA Monday Aug 0
10: 1992-08-03 AQZXMV MV NA Monday Aug 0
前5行被标记为＆＃34; EndOfMonth＆＃34;。
这里有30行数据：
structure(list(Date = structure(c(8247, 8247, 8247, 8247, 8247,
8247, 8247, 8247, 8247, 8247, 8247, 8247, 8247, 8247, 8247, 8247,
8247, 8247, 8247, 8247, 8247, 8250, 8250, 8250, 8250, 8250, 8250,
8250, 8250, 8250, 8250), class = "Date"), Companyvar = structure(c(50L,
51L, 52L, 53L, 54L, 55L, 56L, 57L, 58L, 59L, 60L, 61L, 62L, 63L,
64L, 65L, 66L, 67L, 68L, 69L, 70L, 1L, 2L, 3L, 4L, 5L, 6L, 7L,
8L, 9L, 10L), .Label = c("AIZXMV", "AIZXRI", "AIZXTD", "AIZXND",
"AQZXMV", "AQZXRI", "AQZXTD", "AQZXND", "AIAYMV", "AIAYRI", "AIAYTD",
"AIAYND", "AZJXMV", "AZJXRI", "AZJXTD", "AZJXND", "CHRXMV", "CHRXRI",
"CHRXTD", "CHRXND", "CLXXMV", "CLXXRI", "CLXXTD", "CLXXND", "KSCXMV",
"KSCXRI", "KSCXTD", "KSCXND", "LAUXMV", "LAUXRI", "LAUXTD", "LAUXND",
"MQAXMV", "MQAXRI", "MQAXTD", "MQAXND", "MRMXMV", "MRMXRI", "MRMXTD",
"MRMXND", "QANXMV", "QANXRI", "QANXTD", "QANXND", "QUBXMV", "QUBXRI",
"QUBXTD", "QUBXND", "REXXMV", "REXXRI", "REXXTD", "REXXND", "SYDXMV",
"SYDXRI", "SYDXTD", "SYDXND", "TTIXMV", "TTIXRI", "TTIXTD", "TTIXND",
"TCLXMV", "TCLXRI", "TCLXTD", "TCLXND", "VAHXMV", "VAHXRI", "VAHXTD",
"VAHXND", "ASXMV", "ASXRI"), class = "factor"), variable = structure(c(1L,
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L,
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), class = "factor", .Label = c("MV",
"ND", "RI", "TD")), value = c(NA_real_, NA_real_, NA_real_, NA_real_,
NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_,
NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_,
NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_,
NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_),
DOW = c("Friday", "Friday", "Friday", "Friday", "Friday",
"Friday", "Friday", "Friday", "Friday", "Friday", "Friday",
"Friday", "Friday", "Friday", "Friday", "Friday", "Friday",
"Friday", "Friday", "Friday", "Friday", "Monday", "Monday",
"Monday", "Monday", "Monday", "Monday", "Monday", "Monday",
"Monday", "Monday"), Month = c("Jul", "Jul", "Jul", "Jul",
"Jul", "Jul", "Jul", "Jul", "Jul", "Jul", "Jul", "Jul", "Jul",
"Jul", "Jul", "Jul", "Jul", "Jul", "Jul", "Jul", "Jul", "Aug",
"Aug", "Aug", "Aug", "Aug", "Aug", "Aug", "Aug", "Aug", "Aug"
), EndOfMonth = c(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)), .Names = c("Date",
"Companyvar", "variable", "value", "DOW", "Month", "EndOfMonth"
), class = c("data.table", "data.frame"), row.names = c(NA, -31L
), .internal.selfref = <pointer: 0x000000000b000788>)
干杯