如何从data.frame中选择行和列的子集

Question

I have this

d[d$Age > "2", ]

and it returns all the rows that have an Age of over 2, but I want to only return the values in a few of the columns, say d$X and d$Y, not all of them.

anyway i can do this?

Thanks

Answer 1

d[d$Age > "2", c("X","Y")]

Answer 2

另一种方式

subset(d, Age > "2", select=c(X, Y))