Count pairs of adjacent symbols/elements in a character vector.
pair.counts(x, case=c("lower", "upper", "as is"), circular=TRUE)A matrix of counts. The row and column labels correspond to the first and second element of each pair, respectively.
a character vector or an object that can be coersed to a character vector.
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 considered as distinct elements and counted separately.
Determines if the vector should be treated as circular or not. The default is
TRUE, meaning that the start and end of the sequence will be joined
together for the purpose of counting.
Andrew Hart and Servet Martínez
When circular is TRUE, the vector is treated as circular so that
the some of all the counts in the resulting matrix is equal to the length of the
vector and the row and column sums are equivalent. When circular is
FALSE, the sum of all the entries in the counts matrix will be one less
than the length of the vector and there will be a discrepancy between the row
and column sums.
triple.counts, quadruple.counts,
cylinder.counts,
array2vector, table2vector