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I need to put the value of variable "A" in place of the NA of variable "B".
Example of my dataframe:

> df <- data.frame(A = seq(1, 10), B = c(1, NA, 3, 4, NA, NA, 7, 8, NA, NA))
> df
    A  B
1   1  1
2   2 NA
3   3  3
4   4  4
5   5 NA
6   6 NA
7   7  7
8   8  8
9   9 NA
10 10 NA

I want the above dataframe converted into this:

> df
    A  B
1   1  1
2   2  2
3   3  3
4   4  4
5   5  5
6   6  6
7   7  7
8   8  8
9   9  9
10 10 10
Cesar_Gonzalez_F
  • 9
  • 1

3 Answers3

2

Using R base indexing

> df$B[is.na(df$B)] <- df$A[is.na(df$B)]
> df
    A  B
1   1  1
2   2  2
3   3  3
4   4  4
5   5  5
6   6  6
7   7  7
8   8  8
9   9  9
10 10 10
Jilber Urbina
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2

Use coalesce

library(dplyr)
df <- df %>%
     mutate(B = coalesce(B, A))

-output

df
 A  B
1   1  1
2   2  2
3   3  3
4   4  4
5   5  5
6   6  6
7   7  7
8   8  8
9   9  9
10 10 10
akrun
  • 874,273
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2

I prefer coalesce. Here is one with an ifelse:

library(dplyr)
df %>% 
  mutate(B = ifelse(is.na(B), A, B))

   A  B
1   1  1
2   2  2
3   3  3
4   4  4
5   5  5
6   6  6
7   7  7
8   8  8
9   9  9
10 10 10
TarJae
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