有條件地替換 R 中的值

Question

我在 R 有一個問題。 我有一個數據集，我想根據相鄰列的值更改其單元格

Data <- tibble(a = 1:5,  
b = c("G","H","I","J","K"),
c = c("G","H","J","I","J"))

我想改變chr。 如果 b 和 c 具有相同的字符，則為 NA。

所需 output

Data <- tibble(a = 1:5,  
    b = c("NA","NA","I","J","K"),
    c = c("NA","NA","J","I","J"))

非常感謝您提前提供的幫助。

Answer 1

library(data.table)
setDT(Data)[b == c, c("b", "c") := NA]
#    a    b    c
# 1: 1 <NA> <NA>
# 2: 2 <NA> <NA>
# 3: 3    I    J
# 4: 4    J    I
# 5: 5    K    J

Answer 2

帶底座 R：

Data[Data$b == Data$c, c('b', 'c')] <- "NA"
Data
# # A tibble: 5 x 3
#       a b     c    
# <int> <chr> <chr>
# 1     1 NA    NA   
# 2     2 NA    NA   
# 3     3 I     J    
# 4     4 J     I    
# 5     5 K     J  

Answer 3

使用which對b和c具有相同值的行上的Data進行子集化：

Data[c("b","c")][which(Data$b == Data$c),] <- NA

結果：

Data
# A tibble: 5 x 3
      a b     c    
  <int> <chr> <chr>
1     1 NA    NA   
2     2 NA    NA   
3     3 I     J    
4     4 J     I    
5     5 K     J 

Answer 4

帶dplyr

library(dplyr)
Data %>%
  rowwise() %>% 
  mutate(b = ifelse(b %in% c & c %in% b, "NA", b))%>%
  mutate(c = ifelse(b == "NA", "NA", c))

Output：

      a b     c    
  <int> <chr> <chr>
1     1 NA    NA   
2     2 NA    NA   
3     3 I     J    
4     4 J     I    
5     5 K     J    

Answer 5

另一個基地 R 選項

cols <- c("b", "c")
Data[cols] <- replace(Data[cols], Data[cols] == Data[rev(cols)], NA)

給

> Data
# A tibble: 5 x 3
      a b     c
  <int> <chr> <chr>
1     1 NA    NA
2     2 NA    NA
3     3 I     J
4     4 J     I
5     5 K     J