How to swap (translate) values inside a vector

Question

Let

vetA <- c(1,2,1,2,1,3,4,1,2,3,2,1,4)

What are the possibilities so I could do the following swap? Swap:

• 1 --> 3
• 2 --> 4
• 3 --> 2
• 4 --> 1

I have tried this:

vetB <- as.factor(vetA)
levels(vetB) <- c(3,4,2,1)
vetA <- as.integer(vetB)

# because
print(vetB)
# [1] 3 4 3 4 3 2 1 3 4 2 4 3 1
#Levels: 3 4 2 1

It didn't work. Could you please give me a hand?

Answer 1

One possible option would be to use match:

vetA <- c(1,2,1,2,1,3,4,1,2,3,2,1,4)
old=c(1,2,3,4)
new=c(3,4,2,1)
new[match(vetA,old)]

Output:

3 4 3 4 3 2 1 3 4 2 4 3 1

Hope this helps!

Answer 2

If you converted your factor vector to character before converting it to integer, your code will work. Notice that factor is internally stored as integer, so as.integer(vetB) would return its integer levels.

vetA <- c(1,2,1,2,1,3,4,1,2,3,2,1,4)

vetB <- as.factor(vetA)
levels(vetB) <- c(3,4,2,1)
vetA <- as.integer(as.character(vetB))
vetA
# [1] 3 4 3 4 3 2 1 3 4 2 4 3 1