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

 dataset$base <- as.integer(as.factor(dataset$aresult))

Depending on your data as.factor() could be omitted, because in many cases strings are factor by default, e.g. with read.table