This produces a crosstable between two integer vectors (partitions) of
the same length with a given maximum vector entry k so that the
size of the table is k*k with zeroes for missing entries
between 1 and k (the command table does pretty
much the same thing but will leave out missing entries).
Usage
xtable(c1,c2,k)
Arguments
c1
vector of integers.
c2
vector of integers of same length as c1.
k
integer. Must be larger or equal to maximum entry in
c1 and c2.
Value
A matrix of dimensions c(k,k). Entry [i,j] gives the
number of places in which c1==i & c2==j.