消除dplyr冗余功能行

Question

library(dplyr)

# Example 1 -----------------------------------------------------
mtcars %>% 
  mutate(dubcyl = cyl * 2, dubcyl.avg = mean(.$dubcyl)) %>% 
  as_tibble()
#> Warning message:
#> In mean.default(.$dubcyl) :
#>   argument is not numeric or logical: returning NA

# Example 2 -----------------------------------------------------
mtcars %>% 
  mutate(dubcyl = cyl * 2) %>% 
  mutate(dubcyl.avg = mean(.$dubcyl)) %>% 
  as_tibble()

是否有一种方法可以创建我想要的dubcyl列，如示例1 所示，而不必两次突变，如示例2 所示？

Answer 1

我们在这里不需要.$

library(tibble)
librrary(dplyr)
mtcars %>% 
   mutate(dubcyl = cyl * 2, dubcyl.avg = mean(dubcyl)) %>% 
   as_tibble()