如果您提供除裸函数名称之外的任何内容.predicate
in mutate_if
(以及其他地方.funs
突然出现在dplyr
),您需要执行以下操作之一:
- 将函数包装在匿名函数中
- 使用速记公式语法
~
做基本上相同的事情。
- 此处不适用,但有时
...
让您添加额外的参数.funs
,这样你就可以提供max_value = 30
作为一个论据mutate
. For mutate_if
,仅适用于要应用的函数,不适用于.predicate
.
funct_change <- function(x, max_value){
max(x, na.rm = TRUE) > max_value
}
library(dplyr)
mtcars %>% mutate_if(function(x) funct_change(x, 30), as.character) %>% glimpse()
#> Observations: 32
#> Variables: 11
#> $ mpg <chr> "21", "21", "22.8", "21.4", "18.7", "18.1", "14.3", "24.4...
#> $ cyl <dbl> 6, 6, 4, 6, 8, 6, 8, 4, 4, 6, 6, 8, 8, 8, 8, 8, 8, 4, 4, ...
#> $ disp <chr> "160", "160", "108", "258", "360", "225", "360", "146.7",...
#> $ hp <chr> "110", "110", "93", "110", "175", "105", "245", "62", "95...
#> $ drat <dbl> 3.90, 3.90, 3.85, 3.08, 3.15, 2.76, 3.21, 3.69, 3.92, 3.9...
#> $ wt <dbl> 2.620, 2.875, 2.320, 3.215, 3.440, 3.460, 3.570, 3.190, 3...
#> $ qsec <dbl> 16.46, 17.02, 18.61, 19.44, 17.02, 20.22, 15.84, 20.00, 2...
#> $ vs <dbl> 0, 0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, ...
#> $ am <dbl> 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, ...
#> $ gear <dbl> 4, 4, 4, 3, 3, 3, 3, 4, 4, 4, 4, 3, 3, 3, 3, 3, 3, 4, 4, ...
#> $ carb <dbl> 4, 4, 1, 1, 2, 1, 4, 2, 2, 4, 4, 3, 3, 3, 4, 4, 4, 1, 2, ...
mtcars %>% mutate_if(~ funct_change(., 30), as.character) %>% glimpse()
#> Observations: 32
#> Variables: 11
#> $ mpg <chr> "21", "21", "22.8", "21.4", "18.7", "18.1", "14.3", "24.4...
#> $ cyl <dbl> 6, 6, 4, 6, 8, 6, 8, 4, 4, 6, 6, 8, 8, 8, 8, 8, 8, 4, 4, ...
#> $ disp <chr> "160", "160", "108", "258", "360", "225", "360", "146.7",...
#> $ hp <chr> "110", "110", "93", "110", "175", "105", "245", "62", "95...
#> $ drat <dbl> 3.90, 3.90, 3.85, 3.08, 3.15, 2.76, 3.21, 3.69, 3.92, 3.9...
#> $ wt <dbl> 2.620, 2.875, 2.320, 3.215, 3.440, 3.460, 3.570, 3.190, 3...
#> $ qsec <dbl> 16.46, 17.02, 18.61, 19.44, 17.02, 20.22, 15.84, 20.00, 2...
#> $ vs <dbl> 0, 0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, ...
#> $ am <dbl> 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, ...
#> $ gear <dbl> 4, 4, 4, 3, 3, 3, 3, 4, 4, 4, 4, 3, 3, 3, 3, 3, 3, 4, 4, ...
#> $ carb <dbl> 4, 4, 1, 1, 2, 1, 4, 2, 2, 4, 4, 3, 3, 3, 4, 4, 4, 1, 2, ...
创建于 2018-04-10代表包 http://reprex.tidyverse.org(v0.2.0)。