在R函数

Question

这个问题与类似的帖子有关。 Function writing passing column reference to group_by

但是，我想将几​​个输入传递给使用group_by_（）和summarise_（）的函数。

这是我的功能：

foo <- function(data,column,x1,x2){
    data %>%
            group_by_(.dots = column) %>%
            summarise_(.dots= c(~mean(x1), ~mean(x2)))
}

然而，当我跑

时

foo(mtcars,"cyl", "disp", "hp")

我收到以下错误。

Error in UseMethod("as.lazy_dots") : 
  no applicable method for 'as.lazy_dots' applied to an object of class "c('double', 'numeric')"
In addition: Warning message:
In mean.default(x1) : argument is not numeric or logical: returning NA

谁能告诉我我哪里做错了？

Answer 1

好吧，看起来你只想再次summarise_each，它有一个标准的评估替代方案，summarise_each_。你可以把foo写成

foo <- function(data, column, x1, x2){
    data %>%
            group_by_(.dots = column) %>%
            summarise_each_(funs(mean), c(x1,x2))
}

并用

调用它

foo(mtcars,"cyl", "disp", "hp")
# Source: local data frame [3 x 3]
# 
#     cyl     disp        hp
#   (dbl)    (dbl)     (dbl)
# 1     4 105.1364  82.63636
# 2     6 183.3143 122.28571
# 3     8 353.1000 209.21429