Math::GSL::Combination - Combinations
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);
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.
For more informations on the functions, we refer you to the GSL offcial
documentation: <http://www.gnu.org/software/gsl/manual/html_node/>
Jonathan "Duke" Leto <jonathan@leto.net> and Thierry Moisan
<thierry.moisan@gmail.com>
Copyright (C) 2008-2011 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.