I wanna convert a column with three different character values to numeric.

the column is long but the head is: 
Yes
No
No 
Maybe 
No
Yes

I want it to look like this: 
2
1
1
3
1
2

the problem is that I wanna specify which value would get which number, its important that "Yes" would get the value 2, "No" would get the value 1 and "Maybe" get the value 3. 

I tried using as.numeric but it decides what values on its own.