根据其他列的条件提取数据框的行子集

我有一个dataframe像下面这样的：

x <- data.table(Tickers=c("A","A","A","B","B","B","B","D","D","D","D"),
                Type=c("put","call","put","call","call","put","call","put","call","put","call"),
                Strike=c(35,37.5,37.5,10,11,11,12,40,40,42,42),
                Other=sample(20,11))

    Tickers Type Strike Other
 1:       A  put   35.0     6
 2:       A call   37.5     5
 3:       A  put   37.5    13
 4:       B call   10.0    15
 5:       B call   11.0    12
 6:       B  put   11.0     4
 7:       B call   12.0    20
 8:       D  put   40.0     7
 9:       D call   40.0    11
10:       D  put   42.0    10
11:       D call   42.0     1

我正在尝试分析数据的子集。我想获取的子集是ticker和strike相同的数据。但是我也只想在下存在aput和acall时获取这些数据type。以上面的数据为例，我想返回以下结果：

x[c(2,3,5,6,8:11),]

   Tickers Type Strike Other
1:       A call   37.5     5
2:       A  put   37.5    13
3:       B call   11.0    12
4:       B  put   11.0     4
5:       D  put   40.0     7
6:       D call   40.0    11
7:       D  put   42.0    10
8:       D call   42.0     1

我不确定执行此操作的最佳方法是什么。我的思考过程是我应该创建另一个列向量，例如

x$id <- paste(x$Tickers,x$Strike,sep="_")

然后使用此向量仅提取存在多个ID的值。

x[x$id %in% x$id[duplicated(x$id)],]

   Tickers Type Strike Other     id
1:       A call   37.5     5 A_37.5
2:       A  put   37.5    13 A_37.5
3:       B call   11.0    12   B_11
4:       B  put   11.0     4   B_11
5:       D  put   40.0     7   D_40
6:       D call   40.0    11   D_40
7:       D  put   42.0    10   D_42
8:       D call   42.0     1   D_42

我不确定这样做的效率如何，因为我的实际数据包含更多行。同样，该解决方案不检查type存在一个put和一个的条件call。

标题的措词可能会好很多，我很抱歉

编辑：：：已签出该帖子查找所有重复的行，包括“带有较小下标的元素”

我也可以使用以下解决方案：

x$id <- paste(x$Tickers,x$Strike,sep="_")
x[duplicated(x$id) | duplicated(x$id,fromLast=T),]