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AI::Genetic::Pro - Efficient genetic algorithms for professional purpose with support for multiprocessing.

=head1 SYNOPSIS

    use AI::Genetic::Pro;
    
    sub fitness {
        my ($ga, $chromosome) = @_;
        return oct('0b' . $ga->as_string($chromosome)); 
    }
    
    sub terminate {
        my ($ga) = @_;
        my $result = oct('0b' . $ga->as_string($ga->getFittest));
        return $result == 4294967295 ? 1 : 0;
    }
    
    my $ga = AI::Genetic::Pro->new(        
        -fitness         => \&fitness,        # fitness function
        -terminate       => \&terminate,      # terminate function
        -type            => 'bitvector',      # type of chromosomes
        -population      => 1000,             # population
        -crossover       => 0.9,              # probab. of crossover
        -mutation        => 0.01,             # probab. of mutation
        -parents         => 2,                # number  of parents
        -selection       => [ 'Roulette' ],   # selection strategy
        -strategy        => [ 'Points', 2 ],  # crossover strategy
        -cache           => 0,                # cache results
        -history         => 1,                # remember best results
        -preserve        => 3,                # remember the bests
        -variable_length => 1,                # turn variable length ON
        -mce             => 1,                # optional MCE support
        -workers         => 3,                # number of workers (MCE)
    );
	
    # init population of 32-bit vectors
    $ga->init(32);
	
    # evolve 10 generations
    $ga->evolve(10);
    
    # best score
    print "SCORE: ", $ga->as_value($ga->getFittest), ".\n";
    
    # save evolution path as a chart
    $ga->chart(-filename => 'evolution.png');
     
    # save state of GA
    $ga->save('genetic.sga');
    
    # load state of GA
    $ga->load('genetic.sga');

=head1 DESCRIPTION

This module provides efficient implementation of a genetic algorithm for
professional purpose with support for multiprocessing. It was designed to operate as fast as possible
even on very large populations and big individuals/chromosomes. C<AI::Genetic::Pro> 
was inspired by C<AI::Genetic>, so it is in most cases compatible 
(there are some changes). Additionally C<AI::Genetic::Pro> isn't a pure Perl solution, so it 
doesn't have limitations of its ancestor (such as slow-down in the
case of big populations ( >10000 ) or vectors with more than 33 fields).

If You are looking for a pure Perl solution, consider L<AI::Genetic>.

=over 4

=item Speed

To increase speed XS code is used, however with portability in 
mind. This distribution was tested on Windows and Linux platforms 
(and should work on any other).

Multicore support is available through Many-Core Engine (C<MCE>). 
You can gain the most speed up for big populations or time/CPU consuming 
fitness functions, however for small populations and/or simple fitness 
function better choice will be single-process version.

You can get even more speed up if you turn on use of native arrays 
(parameter: C<native>) instead of packing chromosomes into single scalar. 
However you have to remember about expensive memory use in that case.

=item Memory

This module was designed to use as little memory as possible. A population
of size 10000 consisting of 92-bit vectors uses only ~24MB (C<AI::Genetic> 
would use about 78MB). However - if you use MCE - there will be bigger 
memory consumption. This is consequence of necessity of synchronization 
between many processes.

=item Advanced options

To provide more flexibility C<AI::Genetic::Pro> supports many 
statistical distributions, such as C<uniform>, C<natural>, C<chi_square>
and others. This feature can be used in selection and/or crossover. See
the documentation below.

=back

=head1 METHODS

=over 4

=item I<$ga>-E<gt>B<new>( %options )

Constructor. It accepts options in hash-value style. See options and 
an example below.

=over 8

=item -fitness

This defines a I<fitness> function. It expects a reference to a subroutine.

=item -terminate 

This defines a I<terminate> function. It expects a reference to a subroutine.

=item -type

lib/AI/Genetic/Pro.pm  view on Meta::CPAN

    [ 'b', 'c', 'a' ]    # gene 3
    # ...and so on...

=back

=item I<$ga>-E<gt>B<evolve>($n)

This method causes the GA to evolve the population for the specified number of
generations. If its argument is 0 or C<undef> GA will evolve the population to
infinity unless a C<terminate> function is specified.

=item I<$ga>-E<gt>B<getHistory>()

Get history of the evolution. It is in a format listed below:

	[
		# gen0   gen1   gen2   ...          # generations
		[ max0,  max1,  max2,  ... ],       # max values
		[ mean,  mean1, mean2, ... ],       # mean values
		[ min0,  min1,  min2,  ... ],       # min values
	]

=item I<$ga>-E<gt>B<getAvgFitness>()

Get I<max>, I<mean> and I<min> score of the current generation. In example:

    my ($max, $mean, $min) = $ga->getAvgFitness();

=item I<$ga>-E<gt>B<getFittest>($n, $unique)

This function returns a list of the fittest chromosomes from the current
population.  You can specify how many chromosomes should be returned and if
the returned chromosomes should be unique. See example below.

    # only one - the best
    my ($best) = $ga->getFittest;

    # or 5 bests chromosomes, NOT unique
    my @bests = $ga->getFittest(5);

    # or 7 bests and UNIQUE chromosomes
    my @bests = $ga->getFittest(7, 1);

If you want to get a large number of chromosomes, try to use the
C<getFittest_as_arrayref> function instead (for efficiency).

=item I<$ga>-E<gt>B<getFittest_as_arrayref>($n, $unique)

This function is very similar to C<getFittest>, but it returns a reference 
to an array instead of a list. 

=item I<$ga>-E<gt>B<generation>()

Get the number of the current generation.

=item I<$ga>-E<gt>B<people>()

Returns an anonymous list of individuals/chromosomes of the current population. 

B<IMPORTANT:> the actual array reference used by the C<AI::Genetic::Pro> 
object is returned, so any changes to it will be reflected in I<$ga>.

=item I<$ga>-E<gt>B<chromosomes>()

Alias for C<people>.

=item I<$ga>-E<gt>B<chart>(%options)

Generate a chart describing changes of min, mean, and max scores in your
population. To satisfy your needs, you can pass the following options:

=over 4

=item -filename

File to save a chart in (B<obligatory>).

=item -title

Title of a chart (default: I<Evolution>).

=item -x_label

X label (default: I<Generations>).

=item -y_label

Y label (default: I<Value>).

=item -format

Format of values, like C<sprintf> (default: I<'%.2f'>).

=item -legend1

Description of min line (default: I<Min value>).

=item -legend2

Description of min line (default: I<Mean value>).

=item -legend3

Description of min line (default: I<Max value>).

=item -width

Width of a chart (default: I<640>).

=item -height

Height of a chart (default: I<480>).

=item -font

Path to font (in *.ttf format) to be used (default: none).

=item -logo

Path to logo (png/jpg image) to embed in a chart (default: none).

=item For example:

	$ga->chart(-width => 480, height => 320, -filename => 'chart.png');

=back

=item I<$ga>-E<gt>B<save>($file)