只有当变量a和b的相应值大于4时，我才想从另一个数据框的列c中提取数据.例如，对于受访者ID 001,a_1和b_1不是都大于4，因此它将返回NA.但是a_3和b_3都大于4，所以它将返回相应的c_3值(即"b").
data <- data.frame(
ID = c("001", "002", "003"),
a_1 = c(2, 5, 7),
a_2 = c(7, 3, 2),
a_3 = c(5, 5, 7),
b_1 = c(1, 7, 3),
b_2 = c(3, 3, 5),
b_3 = c(5, 7, 7),
c_1 = c("a", "b", "c"),
c_2 = c("c", "a", "a"),
c_3 = c("b", "a", "c")
)
期望输出
data <- data.frame(
ID = c("001", "002", "003"),
c_1 = c(NA, "b", NA),
c_2 = c(NA, NA, NA),
c_3 = c("b", "a", "c")
)