R help - Mar 2010 - counts of elements in vector

Assume you have a vector of characters x:
> x
[1] "a" "b" "a" "d" "d"
"c"

I use a function that counts the number of times each string occurs in x:
> sapply(unique(x), function(s) {sum(x == s)})
a b d c
2 1 2 1

Is there a more efficient way of doing this?

Cheers,
/Ali

On Mar 29, 2010, at 6:52 PM, Ali Tofigh wrote:
> Assume you have a vector of characters x:
>
>> x
> [1] "a" "b" "a" "d" "d"
"c"
>
> I use a function that counts the number of times each string occurs  
> in x:
>
>> sapply(unique(x), function(s) {sum(x == s)})
> a b d c
> 2 1 2 1
>
> Is there a more efficient way of doing this?
table(x)
>
-- 

David Winsemius, MD
West Hartford, CT

Try using aggregate( ) 
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