CODEWITHSUNDEEP
r
Benji
Benji

Reputation: 207

Combining two variables in r

I think this is a super easy question, but I can't seem to figure it out.

I have two variables: varA and varB.

varA has values 'a' and NA, and varB has values 'b' and NA.

I want to combine them into one variable varC with value 'a' where varA is =='a' and 'b' where varB is =='b'.

I have tried this:

varC <- varA
varC[varB=='b'] <- varB

but I get the error:

Error in [<-.factor(tmp, varB == "b", : NAs are not allowed in subscripted assignments

What am I doing wrong here?

Upvotes: 0

Views: 4808

Answers (1)

Alex P
Alex P

Reputation: 1494

The condition varB=='b' will return NA when varB is NA. Use is.na() to test for NA. Here is an example:

a <- c(NA, 'a', NA)
b <- c('b', NA, 'b')

c <- a
c[is.na(c)] <- b[is.na(c)]

c

[1] "b" "a" "b"

Upvotes: 1

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