## SYNOPSIS

use Math::GSL qw/:all/;

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

my $c = Math::GSL::Combination->new(6,3);

print join (" ", $c->as_list) . "\n";

$c->next;

print join (" ", $c->as_list) . "\n";

my $fd = gsl_fopen('combination.dat', 'w');

gsl_combination_fwrite($fd, $c->raw);

gsl_fclose($fd);

## DESCRIPTION

Here is a list of all the functions in this module :-
`"gsl_combination_alloc($n, $k)"`This function allocates memory for a new combination with parameters

`$n`,`$k`. The combination is not initialized and its elements are undefined. Use the function gsl_combination_calloc if you want to create a combination which is initialized to the lexicographically first combination. -
`"gsl_combination_calloc($n, $k)"`This function allocates memory for a new combination with parameters

`$n`,`$k`and initializes it to the lexicographically first combination. -
`"gsl_combination_init_first($c)"`This function initializes the combination

`$c`to the lexicographically first combination, i.e. (0,1,2,...,k-1). -
`"gsl_combination_init_last($c)"`This function initializes the combination

`$c`to the lexicographically last combination, i.e. (n-k,n-k+1,...,n-1). -
`"gsl_combination_free($c)"`This function frees all the memory used by the combination

`$c`. -
`"gsl_combination_memcpy($dest, $src)"`This function copies the elements of the combination

`$src`into the combination`$dest`. The two combinations must have the same size. -
`"gsl_combination_get($c, $i)"`This function returns the value of the i-th element of the combination

`$c`. If`$i`lies outside the allowed range of 0 to k-1 then the error handler is invoked and 0 is returned. -
`"gsl_combination_fwrite($stream, $c)"`This function writes the elements of the combination

`$c`to the stream`$stream`, opened with the gsl_fopen function from the Math::GSL module, in binary format. The function returns`$GSL_EFAILED`if there was a problem writing to the file. Since the data is written in the native binary format it may not be portable between different architectures. -
`"gsl_combination_fread($stream, $c)"`This function reads elements from the open stream

`$stream`, opened with the gsl_fopen function from the Math::GSL module, into the combination`$c`in binary format. The combination`$c`must be preallocated with correct values of n and k since the function uses the size of`$c`to determine how many bytes to read. The function returns`$GSL_EFAILED`if there was a problem reading from the file. The data is assumed to have been written in the native binary format on the same architecture. -
`"gsl_combination_fprintf($stream, $c, $format)"`This function writes the elements of the combination

`$c`line-by-line to the stream`$stream`, opened with the gsl_fopen function from the Math::GSL module, using the format specifier`$format`, which should be suitable for a type of size_t. In ISO C99 the type modifier z represents size_t, so ``%zu\n'' is a suitable format. The function returns`$GSL_EFAILED`if there was a problem writing to the file. -
`"gsl_combination_fscanf($stream, $c)"`This function reads formatted data from the stream

`$stream`into the combination`$c`. The combination`$c`must be preallocated with correct values of n and k since the function uses the size of`$c`to determine how many numbers to read. The function returns`$GSL_EFAILED`if there was a problem reading from the file. -
`"gsl_combination_n($c)"`This function returns the range (n) of the combination

`$c`. -
`"gsl_combination_k($c)"`This function returns the number of elements (k) in the combination

`$c`. -
`"gsl_combination_data($c)"`This function returns a pointer to the array of elements in the combination

`$c`. -
`"gsl_combination_valid($c)"`This function checks that the combination

`$c`is valid. The k elements should lie in the range 0 to n-1, with each value occurring once at most and in increasing order. -
`"gsl_combination_next($c)"`This function advances the combination

`$c`to the next combination in lexicographic order and returns`$GSL_SUCCESS`. If no further combinations are available it returns`$GSL_FAILURE`and leaves`$c`unmodified. Starting with the first combination and repeatedly applying this function will iterate through all possible combinations of a given order. -
`"gsl_combination_prev($c)"`This function steps backwards from the combination

`$c`to the previous combination in lexicographic order, returning`$GSL_SUCCESS`. If no previous combination is available it returns`$GSL_FAILURE`and leaves`$c`unmodified.

## MORE INFO

For more information on the functions, we refer you to the GSL offcial documentation: <http://www.gnu.org/software/gsl/manual/html_node/>## COPYRIGHT AND LICENSE

Copyright (C) 2008-2011 Jonathan ``Duke'' Leto and Thierry MoisanThis program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.