Count Triplets in Character Vectors
Description
Count triples of adjacent symbols/elements in a character vector.
Usage
1  triple.counts(x, case=c("lower", "upper", "as is"), circular=TRUE)

Arguments
x 
a character vector or an object that can be coersed to a character vector. 
case 
determines how labels for the array should be generated: in 'lower' case, in ' upper' case or 'as is', in which case labels such as 'b' and 'B' will be counted as distinct elements and counted separately. 
circular 
Determines if the vector should be treated as circular or not. The default is

Details
If circular
is TRUE
, the vector is treated as circular so that the
some of all the counts in the resulting array is equal to the length of the
vector and the sums across all dimentions of the array are equivalent, that is:
if we write
t < triple.counts(x)
for some character sequence x, then
apply(t,1,sum)
, apply(t,2,sum)
and apply(t,3,sum)
are all identical.
On the other hand, if circular
is FALSE
, the sum of all the
entries in the counts array will be two less than the length of the vector and
there will be a discrepancy between the sums over the various dimensions.
Value
A 3dimensional array of counts. The labels of the ith dimension correspond to the ith element of each triple, where i is either 1, 2 or 3.
Author(s)
Andrew Hart and Servet Mart<ed>nez
See Also
pair.counts
, quadruple.counts
,
cylinder.counts
,
array2vector
, table2vector