GNU R permutations of multisets in Cool-Lex order
A set of tools to permute multisets without loops or hash tables and to
generate integer partitions. The permutation functions are based on C
code from Aaron Williams. Cool-lex order is similar to colexicographical
order. The algorithm is described in Williams, A. Loopless Generation of
Multiset Permutations by Prefix Shifts. SODA 2009, Symposium on Discrete
Algorithms, New York, United States. The permutation code is distributed
without restrictions. The code for stable and efficient computation of
multinomial coefficients comes from Dave Barber. The code can be
download from <http://tamivox.org/dave/multinomial/index.html> and is
distributed without conditions. The package also generates the integer
partitions of a positive, non-zero integer n. The C code for this is
based on Python code from Jerome Kelleher which can be found here
<http://jeromekelleher.net/category/combinatorics.html>. The C code
and Python code are distributed without conditions.
