Replace characters from a column of a data frame R

Question

I have a data frame

a <- runif (10)
b <- letters [1:10]
c <- c(rep (\"A-B\", 4), rep(\"A_C\", 6))
data1 <- data.frame (a, b, c)
data1
         


        

Answer 1

If your variable data1$c is a factor, it's more efficient to change the labels of the factor levels than to create a new vector of characters:

levels(data1$c) <- sub("_", "-", levels(data1$c))


            a b   c
1  0.73945260 a A-B
2  0.75998815 b A-B
3  0.19576725 c A-B
4  0.85932140 d A-B
5  0.80717115 e A-C
6  0.09101492 f A-C
7  0.10183586 g A-C
8  0.97742424 h A-C
9  0.21364521 i A-C
10 0.02389782 j A-C