NAME

       Math::GSL::Multiset - Multisets manipulation

SYNOPSIS

           use Math::GSL::Multiset qw/:all/;

           my $ms = Math::GSL::Multiset->($n, $k);

           my $value = $ms->get(2);

           # compute next multiset
           $ms->next;
           # compute the previous multiset

           # clone a multiset
           my $other = $ms->clone();

DESCRIPTION

       A multiset c is represented by an array of k integers in the range 0 to n-1, where each
       value c_i may occur more than once. The multiset c corresponds to indices of k elements
       chosen from an n element vector with replacement. In mathematical terms, n is the
       cardinality of the multiset while k is the maximum multiplicity of any value.

   Object Oriented API
       Handy Perl-style OO API for Multisets.

       "new"
           Creates a new multiset with parameters n, k and initializes it to the
           lexicographically first multiset element, i.e., 0 repeated k times.

               my $ms = Math::GSL::Multiset->($n, $k);

       "init_first"
           Initializes the multiset to the lexicographically first multiset element, i.e.  0
           repeated k times.

               $ms->init_first;

       "init_last"
           Initializes the multiset c to the lexicographically last multiset element, i.e.  n-1
           repeated k times.

               $ms->init_last;

       "get"
           Returns the value of the i-th element of the multiset. If i lies outside the allowed
           range of 0 to k-1 then the error handler is invoked and 0 is returned.

               my $val = $ms->get($k-1);

       "next"
           Advances the multiset to the next multiset element in lexicographic order and returns
           GSL_SUCCESS. If no further multisets elements are available it returns GSL_FAILURE and
           leaves the multiset unmodified. Starting with the first multiset and repeatedly
           applying this function will iterate through all possible multisets of a given order.

               $ms->next();

       "prev"
               $ms->prev();

           Steps backwards from the multiset to the previous multiset element in lexicographic
           order, returning GSL_SUCCESS. If no previous multiset is available it returns
           GSL_FAILURE and leaves the multiset unmodified.

       "to_list"
           Creates a Perl list of integers with the values from the multiset, starting at index 0
           and ending at index $k-1.

               @data = $ms->to_list;

       "clone"
           Creates a new multiset with the same size, and same values.

               my $new = $ms->clone;

   GSL API
       For reference on these methds, please consult the GSL documentation.

       "gsl_multiset_calloc"
       "gsl_multiset_alloc"
       "gsl_multiset_init_first"
       "gsl_multiset_init_last"
       "gsl_multiset_free"
       "gsl_multiset_memcpy"
       "gsl_multiset_get"
       "gsl_multiset_n"
       "gsl_multiset_k"
       "gsl_multiset_data"
       "gsl_multiset_valid"
       "gsl_multiset_next"
       "gsl_multiset_prev"
       "gsl_multiset_fwrite"
       "gsl_multiset_fread"
       "gsl_multiset_fprintf"
       "gsl_multiset_fscanf"

AUTHORS

       Jonathan "Duke" Leto <jonathan@leto.net> and Thierry Moisan <thierry.moisan@gmail.com>

COPYRIGHT AND LICENSE

       Copyright (C) 2008-2023 Jonathan "Duke" Leto and Thierry Moisan

       This program is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.