mutate_at（或跨）和 ifelse 语句

Question

类似于这个问题，给出tmpp：

library(data.table)
library(tidyverse)
tmpp <- data.table(
  "ID" = c(1,1,1,2,2), 
  "Date" = c(1,2,3,1,2), 
  "total_neg" = c(1,1,0,0,2),
  "total_pos" = c(4,5,2,4,5),
  "H1" = c(5,4,0,5,-5),
  "H2" = c(5,-10,5,5,-5),
  "H3" = c(-10,6,5,0,10)
)
tmpp
#    ID Date total_neg total_pos H1  H2  H3
# 1:  1    1         1         4  5   5 -10
# 2:  1    2         1         5  4 -10   6
# 3:  1    3         0         2  0   5   5
# 4:  2    1         0         4  5   5   0
# 5:  2    2         2         5 -5  -5  10

我想H用NAwhere替换所有以,开头的变量total_neg == 1：

#    ID Date total_neg total_pos H1  H2  H3
# 1:  1    1         1         4  NA NA NA
# 2:  1    2         1         5  NA NA NA
# 3:  1    3         0         2  0   5   5
# 4:  2    1         0         4  5   5   0
# 5:  2    2         2         5 -5  -5  10

为什么这些不起作用？

tmpp %>%
  mutate_at(vars(matches("H")), ~ifelse( .$total_neg == 1, NA, .))

tmpp %>%
  mutate_at(vars(matches("H"),
            .funs = list(~ ifelse(.$total_neg == 1, NA, .))))
#im guessing the first dot in the ifelse statements above is referring to the H columns so I tried:
tmpp %>%
  mutate_at(vars(matches("H"),
                 .funs = list(~ ifelse(tmpp$total_neg == 1, NA, .))))

也很高兴看到across版本，谢谢

Answer 1

您不需要$在dplyr管道中使用。mutate_at/中指across的是列值。尝试 ：

library(dplyr)
tmpp %>% mutate(across(starts_with('H'), ~replace(., total_neg == 1, NA)))

#   ID Date total_neg total_pos H1 H2 H3
#1:  1    1         1         4 NA NA NA
#2:  1    2         1         5 NA NA NA
#3:  1    3         0         2  0  5  5
#4:  2    1         0         4  5  5  0
#5:  2    2         2         5 -5 -5 10

Answer 2

一个简单的data.table的解决方案，更新所有列在一次与就地只为子集

tmpp[total_neg == 1, grep("^H", names(tmpp)) := NA]
tmpp
#    ID Date total_neg total_pos H1 H2 H3
# 1:  1    1         1         4 NA NA NA
# 2:  1    2         1         5 NA NA NA
# 3:  1    3         0         2  0  5  5
# 4:  2    1         0         4  5  5  0
# 5:  2    2         2         5 -5 -5 10

Answer 3

您的猜测是正确的：在 purrr 风格的匿名函数内部（在您之后~），.引用的是函数参数，它是一个单列，而不是您通过管道输入的数据帧。解决方案是通过删除.$.

tmpp %>%
  mutate_at(vars(matches("H")), ~ifelse(total_neg == 1, NA, .))
#    ID Date total_neg total_pos H1 H2 H3
# 1:  1    1         1         4 NA NA NA
# 2:  1    2         1         5 NA NA NA
# 3:  1    3         0         2  0  5  5
# 4:  2    1         0         4  5  5  0
# 5:  2    2         2         5 -5 -5 10

如果您想修改“所有以 H 开头的变量”，我强烈建议使用starts_with("H")而不是matches("H").