Creating a new variable from a lookup table

Question

I have the following columns in my data set:

presult     aresult
  I         single
  I         double
  I         triple
  I         home run
  SS        st         


        

Answer 1

define your lookup table

lookup= data.frame( 
        base=c(0,1,2,3,4), 
        aresult=c("strikeout","single","double","triple","home run"))

then use join from plyr

dataset = join(dataset,lookup,by='aresult')