r中2个相关数据帧的子集和合并

我已经搜索了档案，但在这个问题上没有任何结果，我涉及到两个相关数据帧的子集，一个数据帧是一个键，另一个是一个年度列表，我想使用该键创建一个子集和一个索引。我尝试使用子集公式，但我的代码不符合我的标准。以下是数据：

players <- c('Albert Belle','Reggie Jackson', 'Reggie Jackson')
contract_start_season <- c(1999,1977,1982)
contract_end_season <- c(2003, 1981, 1985)
key <- data.frame (player = players, contract_start_season, contract_end_season)
player_data <- data.frame( season = c(seq(1975,1985),seq(1997,2003)), player = c(rep('Reggie Jackson',times=11),rep('Albert Belle', times=7)))

---

players您是否正试图按照以下思路做一些事情

library(data.table)

key <- data.table(key)
player_data <- data.table(player_data)

#Adding another column called season to help in the merge later
key[,season := contract_start_season]

# Index on which to merge
setkeyv(key, c("player","season"))
setkeyv(player_data, c("player","season"))

#the roll = Inf makes it like a closest merge, instead of an exact merge
key[player_data, roll = Inf]

但我想排除那些不重要的年份，比如雷吉·杰克逊的年份是1977年到1981年，然后是1982年到1985年，阿尔伯特·贝尔的年份是1999年到2003年。我对合并没问题，我只是希望它能够根据键中设置的标准进行子集缩小。实际上，只需去掉NA就可以了，我想！让我试试itTry
key[player\u data，roll=Inf][！is.na（合同开始季节）]
library(data.table)

key <- data.table(key)
player_data <- data.table(player_data)

#Adding another column called season to help in the merge later
key[,season := contract_start_season]

# Index on which to merge
setkeyv(key, c("player","season"))
setkeyv(player_data, c("player","season"))

#the roll = Inf makes it like a closest merge, instead of an exact merge
key[player_data, roll = Inf]

> key[player_data, roll = Inf]
            player season contract_start_season contract_end_season
 1:   Albert Belle   1997                    NA                  NA
 2:   Albert Belle   1998                    NA                  NA
 3:   Albert Belle   1999                  1999                2003
 4:   Albert Belle   2000                  1999                2003
 5:   Albert Belle   2001                  1999                2003
 6:   Albert Belle   2002                  1999                2003
 7:   Albert Belle   2003                  1999                2003
 8: Reggie Jackson   1975                    NA                  NA
 9: Reggie Jackson   1976                    NA                  NA
10: Reggie Jackson   1977                  1977                1981
11: Reggie Jackson   1978                  1977                1981
12: Reggie Jackson   1979                  1977                1981
13: Reggie Jackson   1980                  1977                1981
14: Reggie Jackson   1981                  1977                1981
15: Reggie Jackson   1982                  1982                1985
16: Reggie Jackson   1983                  1982                1985
17: Reggie Jackson   1984                  1982                1985
18: Reggie Jackson   1985                  1982                1985