Is it possible to remove this loop? [SEC=UNCLASSIFIED]

Hi all,

I would like create a new column in a data.frame (a1) to store 0, 1 data 

converted from a factor as below.

a1$h2<-NULL
for (i in 1:dim(a1)[1]) {
      if (a1$h1[i]=="H") a1$h2[i]<-1 else a1$h2[i]<-0
      }

My question: is it possible to remove the loop from above code to 

the desired result?

Thanks in advance,
Jin

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