[R] dplyr::c_across 함수로 여러 열을 한 번에 계산하기

dplyr::c_across

- 여러 열을 합쳐주는 역할을 한다

- 예제 데이터

df <- tibble(id = 1:4, w = runif(4), x = runif(4), y = runif(4), z = runif(4))
df %>%
  rowwise() %>%
  mutate(
    sum = sum(c_across(w:z)),
    sd = sd(c_across(w:z))
  )
#> # A tibble: 4 × 7
#> # Rowwise: 
#>      id     w     x     y     z   sum    sd
#>   <int> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1     1 0.790 0.588 0.142 0.225  1.74 0.305
#> 2     2 0.892 0.514 0.781 0.207  2.39 0.305
#> 3     3 0.327 0.317 0.456 0.659  1.76 0.159
#> 4     4 0.351 0.408 0.234 0.715  1.71 0.205

 

목표

- NA값을 제외하고 각 HV5와 HV5를 제외한 값의 평균을 구해보자 

 

 

데이터

data <- tribble(
  ~Site, ~HV1,  ~HV2,   ~HV3,  ~HV4, ~HV5,  ~HV6,   ~HV7, ~HV8,   ~HV9, ~HV10,
  "A",   0.142, 0.0787, NA,    0.338, 0.797, 0.231,  NA,    0.461,  0.442, 0.0579,
  "B",   0.243, 0.0725, 0.354, 0.368, 1.02,  0.105,  NA,    0.555,  0.0644, 0,
  "C",   0,     NaN,   0,     0.605, 0,     0.417,  0.589, 0,      NaN,   0,
  "D",   NaN,   0,     0,     0.111, 0,     0,      0.0412, 0,      NaN,   0,
  "E",    0,     0,     0,     0.188, 0.749, 0.0113, 0.117, 0.499,  0,      0
)
data

 

 

계산 

subject <-c("HV1", "HV2", "HV3", "HV4", "HV6", "HV7", "HV8", "HV9", "HV10")


result <- data %>%
  dplyr::group_by(Site) %>%
  dplyr::summarise(
    mean_HV5 = mean(HV5, na.rm = TRUE),
    mean_Other = mean(c_across(all_of(subject)), na.rm = TRUE)
    )
result

# # A tibble: 5 × 3
# Site  mean_HV5 mean_Other
# <chr>    <dbl>      <dbl>
# 1 A        0.797     0.250 
# 2 B        1.02      0.220 
# 3 C        0         0.230 
# 4 D        0         0.0217
# 5 E        0.749     0.0906

 

 

출처

https://dplyr.tidyverse.org/reference/c_across.html