What is the best way to combine the two mutually exclusive columns in R

Question

I have a data frame like this:

> df <- data.frame(A=c("a",NA,"b"),B=c(NA,"c",NA))
> df
     A    B
1    a <NA>
2 <NA>    c
3    b <NA>

How do I get to:

> df
  A
1 a
2 c
3 b

The answers [here](http://stackoverflow.com/q/19253820/324364) might be helpful. — joran, Apr 01 '14 at 18:36
...also, please pay attention to your tags. The description for the tips-and-tricks tag says in big bold letters not to use it. — joran, Apr 01 '14 at 19:05

score 2 · Accepted Answer · answered Apr 01 '14 at 18:34

2

like this?

 df <- with(df, data.frame(AB=ifelse(is.na(A), as.character(B), as.character(A))))
> df
  AB
1  a
2  c
3  b

answered Apr 01 '14 at 18:34

Jilber Urbina

score 0 · Answer 2 · answered Apr 01 '14 at 18:34

0

There are many ways to do this. Here's one way

data.frame(A=apply(df,1,na.omit))

answered Apr 01 '14 at 18:34

kdauria

2 Answers2