我想获取 n 个变量的所有可能组合中的所有公共(public)元素。
假设我们有 3 个变量:a、b 和 c，每个变量有 4、2 和 3 个元素。我想创建一个数据框，其中一列中包含所有可能的组合(a、b、c、ab、ac、bc 和 abc)，第二列中包含常见元素。示例:
输入:
a<-c("x1","x2","x3","x4")
b<-c("x2","x5")
c<-c("x3","x4","x6")
我想要一个看起来像这样的输出:
name elements
1 a "x1","x2","x3","x4"
2 b "x2","x3","x5"
3 c "x3","x4","x6"
4 ab "x1","x2","x3","x4","x5"
5 ac "x1","x2","x3","x4","x6"
6 bc "x2","x3","x4","x5","x6"
7 abc "x1","x2","x3","x4","x5","x6"
到目前为止我尝试过:
all1<-c("a","b","c")
all2<-list(a,b,c)
all3<-c(a,b,c)
sapply ( 1:3, function(x) combn(all1,x))
sapply ( 1:3, function(x) combn(all2,x))
sapply ( 1:3, function(x) combn(all3,x))
最佳答案
方法有很多，这里是一个:
grid <- expand.grid(a=c(T,F), b=c(T,F), c=c(T,F))
grid$results <- mapply(function(x,y,z) {
unique(c(if(x) a,if(y) b,if(z) c))
},grid$a,grid$b,grid$c)
输出:
a b c results
1 TRUE TRUE TRUE x1, x2, x3, x4, x5, x6
2 FALSE TRUE TRUE x2, x5, x3, x4, x6
3 TRUE FALSE TRUE x1, x2, x3, x4, x6
4 FALSE FALSE TRUE x3, x4, x6
5 TRUE TRUE FALSE x1, x2, x3, x4, x5
6 FALSE TRUE FALSE x2, x5
7 TRUE FALSE FALSE x1, x2, x3, x4
8 FALSE FALSE FALSE NULL
关于R 获取 N 个变量的所有可能组合的所有公共(public)元素，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/42666933/