[R] count the # of appearances...

[Marc Schwartz]

On Thu, 2007-03-01 at 15:20 +0100, bunny , lautloscrew.com wrote:
> Hi there,
> 
> is there a possibility to count the number of appearances of an  
> element in a vector ?
> i mean of any given element.. deliver all elements which are exactly  
> xtimes in this vector ?
> 
> thx in advance !!

Vec <- sample(20, replace = TRUE)

> Vec
 [1] 16  4 16  1 13 13  7 14 20 18 18 18  6  1  8  5 12  8  5  2

# See ?table
> table(Vec)
Vec
 1  2  4  5  6  7  8 12 13 14 16 18 20 
 2  1  1  2  1  1  2  1  2  1  2  3  1


# Get the elements that appear 3 times

Vec.tab <- table(Vec)

> Vec.tab[Vec.tab == 3]
18 
 3 


HTH,

Marc Schwartz