提取数据行。表中的其他数据行。表[副本]

我找不到任何答案,但我认为这很容易做到。

我有这些数据。表:

DT = expand.grid(Season = c("Winter","Spring","Summer","Fall"),
                 Station = c("A","B","C"),
                 Group = c("1","2","3","4"))
DT$Value = seq(1,length(DT[,1]),1)
DT = data.table(DT)

我想获得 DT 根据其他数据。表:

indexTable = data.table(Season = c("Winter","Spring","Spring"),
                        Station = c("B","B","A"),
                        Group = c("1","2","3"))

基本上我只想要 DT公司 包含在 indexTable 。预期结果如下表所示:

expectedTable = data.table(Season = c("Winter","Spring","Spring"),
                           Station = c("B","B","A"),
                           Group = c("1","2","3"),
                           Value = c(5,18,26))

我试图通过此代码获得:

tryTable = DT[DT$Station %in% indexTable$Station &
              DT$Season %in% indexTable$Season &
              DT$Group %in% indexTable$Group,]

这不仅给了我想要的3行,还给了其他几行 DT公司 。

我做错了什么?有没有简单的方法 expectedTable 使用数据。表索引符号(例如使用 setkey ?)