Frequency of letters

Frequency of letters. Given a list of letters, count the number of occurrences of individuals letters.

letterFreq<-function(x)

{

n<-length(x);

fTable<-matrix(0,26,1);

for(i in 1:n)

{

idx<-(1:26)[letters==tolower(x[i])];

fTable[idx] <- fTable[idx] + 1;

}

return(data.frame(letters,fTable));

}

>x<-c("D","a","t","a","s","c","i","e","n","c","e","i","s","f","u","n");

>letterFreq(x)