CODEWITHSUNDEEP
r
Yuki
Yuki

Reputation: 33

Change specific columns to NA when another column equals 0

I am new to r and I have been struggling to do the following. If one value ("y" in the example below) equals to 0, I want to change certain values ("x1" and "x2") to be NA, but leave others unchanged ("x3"). Example:

df <- data.frame(y=c(1,0,1,1,0,0,1,0,1,0), x1=c(NA,3,4,7,NA,8,2,NA,3,7), x2=c(1,NA,4,7,5,6,NA,2,3,1), x3=c(9,5,2,4,7,2,5,8,2,2))

I want the output to be:

   y x1 x2 x3
1  1 NA  1  9
2  0 NA NA  5
3  1  4  4  2
4  1  7  7  4
5  0 NA NA  7
6  0 NA NA  2
7  1  2 NA  5
8  0 NA NA  8
9  1  3  3  2
10 0 NA NA  2

Upvotes: 3

Views: 396

Answers (2)

dww
dww

Reputation: 31452

To do the replacement in 2nd and 3rd columns, you can use 

df[df$y == 0, 2:3] <- NA

Or, to specify the columns by name

df[df$y == 0, c("x1", "x2")] <- NA

Alternatively, using library(data.table), we can do

setDT(df)[y==0, c('x1','x2') := NA]

Upvotes: 1

Ronak Shah
Ronak Shah

Reputation: 388797

We can use mutate_at from dplyr

library(dplyr)
df %>%
  mutate_at(vars(c("x1", "x2")), funs(replace(., y == 0, NA)))

#   y x1 x2 x3
#   1 NA  1  9
#2  0 NA NA  5
#3  1  4  4  2
#4  1  7  7  4
#5  0 NA NA  7
#6  0 NA NA  2
#7  1  2 NA  5
#8  0 NA NA  8
#9  1  3  3  2
#10 0 NA NA  2

Upvotes: 2

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