AI-Genetic-Pro
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lib/AI/Genetic/Pro.pm view on Meta::CPAN
if ($self->strategy->[0] eq 'PMX' or $self->strategy->[0] eq 'OX') and $self->variable_length;
#-------------------------------------------------------------------
$self->_set_strict if $self->strict;
#-------------------------------------------------------------------
return $self unless $self->mce;
#-------------------------------------------------------------------
delete $self->{ mce };
'AI::Genetic::Pro::MCE'->use or die q[Cannot raise multicore support: ] . $@;
return AI::Genetic::Pro::MCE->new( $self, \%args );
}
#=======================================================================
sub _Cache { $_Cache; }
#=======================================================================
# INIT #################################################################
#=======================================================================
sub _set_strict {
my ($self) = @_;
# fitness
my $fitness = $self->fitness();
my $replacement = sub {
my @tmp = @{$_[1]};
my $ret = $fitness->(@_);
my @cmp = @{$_[1]};
die qq/Chromosome was modified in a fitness function from "@tmp" to "@{$_[1]}"!\n/ unless compare(\@tmp, \@cmp);
return $ret;
};
$self->fitness($replacement);
}
#=======================================================================
sub _fitness_cached {
my ($self, $chromosome) = @_;
#my $key = md5_hex(${tied(@$chromosome)});
my $key = md5_hex( $self->_package ? md5_hex( ${ tied( @$chromosome ) } ) : join( q[:], @$chromosome ) );
return $_Cache->{$key} if exists $_Cache->{$key};
$_Cache->{$key} = $self->_fitness_real->($self, $chromosome);
return $_Cache->{$key};
}
#=======================================================================
sub _init_cache {
my ($self) = @_;
$self->_fitness_real($self->fitness);
$self->fitness(\&_fitness_cached);
return;
}
#=======================================================================
sub _check_data_ref {
my ($self, $data_org) = @_;
my $data = clone($data_org);
my $ars;
for(0..$#$data){
next if $ars->{$data->[$_]};
$ars->{$data->[$_]} = 1;
unshift @{$data->[$_]}, undef;
}
return $data;
}
#=======================================================================
# we have to find C to (in some cases) incrase value of range
# due to design model
sub _find_fix_range {
my ($self, $data) = @_;
for my $idx (0..$#$data){
if($data->[$idx]->[1] < 1){
my $const = 1 - $data->[$idx]->[1];
push @{$self->_fix_range}, $const;
$data->[$idx]->[1] += $const;
$data->[$idx]->[2] += $const;
}else{ push @{$self->_fix_range}, 0; }
}
return $data;
}
#=======================================================================
sub init {
my ( $self, $data ) = @_;
croak q/You have to pass some data to "init"!/ unless $data;
#-------------------------------------------------------------------
$self->generation(0);
$self->_init( $data );
$self->_fitness( { } );
$self->_fix_range( [ ] );
$self->_history( [ [ ], [ ], [ ] ] );
$self->_init_cache if $self->cache;
#-------------------------------------------------------------------
if($self->type eq q/listvector/){
croak(q/You have to pass array reference if "type" is set to "listvector"/) unless ref $data eq 'ARRAY';
$self->_translations( $self->_check_data_ref($data) );
}elsif($self->type eq q/bitvector/){
croak(q/You have to pass integer if "type" is set to "bitvector"/) if $data !~ /^\d+$/o;
$self->_translations( [ [ 0, 1 ] ] );
$self->_translations->[$_] = $self->_translations->[0] for 1..$data-1;
}elsif($self->type eq q/combination/){
croak(q/You have to pass array reference if "type" is set to "combination"/) unless ref $data eq 'ARRAY';
$self->_translations( [ clone($data) ] );
$self->_translations->[$_] = $self->_translations->[0] for 1..$#$data;
}elsif($self->type eq q/rangevector/){
croak(q/You have to pass array reference if "type" is set to "rangevector"/) unless ref $data eq 'ARRAY';
$self->_translations( $self->_find_fix_range( $self->_check_data_ref($data) ));
}else{
croak(q/You have to specify first "type" of vector!/);
}
my $size = 0;
if($self->type ne q/rangevector/){ for(@{$self->_translations}){ $size = $#$_ if $#$_ > $size; } }
# else{ for(@{$self->_translations}){ $size = $_->[1] if $_->[1] > $size; } }
else{ for(@{$self->_translations}){ $size = $_->[2] if $_->[2] > $size; } } # Provisional patch for rangevector values truncated to signed 8-bit quantities. Thx to Tod Hagan
my $package = get_package_by_element_size($size);
$self->_package($package);
my $length = ref $data ? sub { $#$data; } : sub { $data - 1 };
if($self->variable_length){
$length = ref $data ? sub { 1 + int( rand( $#{ $self->_init } ) ); } : sub { 1 + int( rand( $self->_init - 1) ); };
}
$self->_length( $length );
$self->chromosomes( [ ] );
push @{$self->chromosomes},
AI::Genetic::Pro::Chromosome->new($self->_translations, $self->type, $package, $length->())
for 1..$self->population;
$self->_calculate_fitness_all();
}
#=======================================================================
# SAVE / LOAD ##########################################################
#=======================================================================
sub spew {
#+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
STORABLE->use( qw( store retrieve freeze thaw ) ) or croak(q/You need "/.STORABLE.q/" module to save a state of "/.__PACKAGE__.q/"!/);
$Storable::Deparse = 1;
$Storable::Eval = 1;
#+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
my ( $self ) = @_;
my $clone = {
_selector => undef,
_strategist => undef,
_mutator => undef,
};
$clone->{ chromosomes } = [ map { ${ tied( @$_ ) } } @{ $self->chromosomes } ]
if $self->_package;
foreach my $key(keys %$self){
next if exists $clone->{$key};
$clone->{$key} = $self->{$key};
}
return $clone;
}
#=======================================================================
sub slurp {
my ( $self, $dump ) = @_;
if( my $typ = $self->_package ){
@{ $dump->{ chromosomes } } = map {
my $arr = $typ->make_with_packed( $_ );
bless $arr, q[AI::Genetic::Pro::Chromosome];
} @{ $dump->{ chromosomes } };
}
%$self = %$dump;
return 1;
}
#=======================================================================
sub save {
my ( $self, $file ) = @_;
croak(q/You have to specify file!/) unless defined $file;
store( $self->spew, $file );
}
#=======================================================================
sub load {
#+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
STORABLE->use( qw( store retrieve freeze thaw ) ) or croak(q/You need "/.STORABLE.q/" module to load a state of "/.__PACKAGE__.q/"!/);
$Storable::Deparse = 1;
$Storable::Eval = 1;
#+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
my ($self, $file) = @_;
croak(q/You have to specify file!/) unless defined $file;
my $clone = retrieve($file);
return carp('Incorrect file!') unless $clone;
return $self->slurp( $clone );
}
#=======================================================================
# CHARTS ###############################################################
#=======================================================================
sub chart {
GD->require or croak(q/You need "/.GD.q/" module to draw chart of evolution!/);
my ($self, %params) = (shift, @_);
my $graph = GD()->new(($params{-width} || 640), ($params{-height} || 480));
my $data = $self->getHistory;
lib/AI/Genetic/Pro.pm view on Meta::CPAN
zero_axis => 1,
#interlaced => 1,
logo_position => 'BR',
legend_placement => 'RT',
bgclr => 'white',
boxclr => '#FFFFAA',
transparent => 0,
title => ($params{'-title'} || q/Evolution/ ),
x_label => ($params{'-x_label'} || q/Generation/),
y_label => ($params{'-y_label'} || q/Value/ ),
( $params{-logo} && -f $params{-logo} ? ( logo => $params{-logo} ) : ( ) )
);
my $gd = $graph->plot( [ [ 0..$#{$data->[0]} ], @$data ] ) or croak($@);
open(my $fh, '>', $params{-filename}) or croak($@);
binmode $fh;
print $fh $gd->png;
close $fh;
return 1;
}
#=======================================================================
# TRANSLATIONS #########################################################
#=======================================================================
sub as_array_def_only {
my ($self, $chromosome) = @_;
return $self->as_array($chromosome)
if not $self->variable_length or $self->variable_length < 2;
if( $self->type eq q/bitvector/ ){
return $self->as_array($chromosome);
}else{
my $ar = $self->as_array($chromosome);
my $idx = first_index { $_ } @$ar;
my @array = @$ar[$idx..$#$chromosome];
return @array if wantarray;
return \@array;
}
}
#=======================================================================
sub as_array {
my ($self, $chromosome) = @_;
if($self->type eq q/bitvector/){
# This could lead to internal error, bacause of underlaying Tie::Array::Packed
#return @$chromosome if wantarray;
#return $chromosome;
my @chr = @$chromosome;
return @chr if wantarray;
return \@chr;
}elsif($self->type eq q/rangevector/){
my $fix_range = $self->_fix_range;
my $c = -1;
#my @array = map { $c++; warn "WARN: $c | ",scalar @$chromosome,"\n" if not defined $fix_range->[$c]; $_ ? $_ - $fix_range->[$c] : undef } @$chromosome;
my @array = map { $c++; $_ ? $_ - $fix_range->[$c] : undef } @$chromosome;
return @array if wantarray;
return \@array;
}else{
my $cnt = 0;
my @array = map { $self->_translations->[$cnt++]->[$_] } @$chromosome;
return @array if wantarray;
return \@array;
}
}
#=======================================================================
sub as_string_def_only {
my ($self, $chromosome) = @_;
return $self->as_string($chromosome)
if not $self->variable_length or $self->variable_length < 2;
my $array = $self->as_array_def_only($chromosome);
return join(q//, @$array) if $self->type eq q/bitvector/;
return join(q/___/, @$array);
}
#=======================================================================
sub as_string {
return join(q//, @{$_[1]}) if $_[0]->type eq q/bitvector/;
return join(q/___/, map { defined $_ ? $_ : q/ / } $_[0]->as_array($_[1]));
}
#=======================================================================
sub as_value {
my ($self, $chromosome) = @_;
croak(q/You MUST call 'as_value' as method of 'AI::Genetic::Pro' object./)
unless defined $_[0] and ref $_[0] and ( ref $_[0] eq 'AI::Genetic::Pro' or ref $_[0] eq 'AI::Genetic::Pro::MCE');
croak(q/You MUST pass 'AI::Genetic::Pro::Chromosome' object to 'as_value' method./)
unless defined $_[1] and ref $_[1] and ref $_[1] eq 'AI::Genetic::Pro::Chromosome';
return $self->fitness->($self, $chromosome);
}
#=======================================================================
# ALGORITHM ############################################################
#=======================================================================
sub _calculate_fitness_all {
my ($self) = @_;
$self->_fitness( { } );
$self->_fitness->{$_} = $self->fitness()->($self, $self->chromosomes->[$_])
for 0..$#{$self->chromosomes};
# sorting the population is not necessary
# my (@chromosomes, %fitness);
# for my $idx (sort { $self->_fitness->{$a} <=> $self->_fitness->{$b} } keys %{$self->_fitness}){
# push @chromosomes, $self->chromosomes->[$idx];
# $fitness{$#chromosomes} = $self->_fitness->{$idx};
# delete $self->_fitness->{$idx};
# delete $self->chromosomes->[$idx];
# }
#
# $self->_fitness(\%fitness);
# $self->chromosomes(\@chromosomes);
return;
}
#=======================================================================
sub _select_parents {
my ($self) = @_;
unless($self->_selector){
croak "You must specify a selection strategy!"
unless defined $self->selection;
my @tmp = @{$self->selection};
my $selector = q/AI::Genetic::Pro::Selection::/ . shift @tmp;
$selector->require or die $!;
$self->_selector($selector->new(@tmp));
}
$self->_parents($self->_selector->run($self));
return;
}
#=======================================================================
sub _crossover {
my ($self) = @_;
unless($self->_strategist){
my @tmp = @{$self->strategy};
my $strategist = q/AI::Genetic::Pro::Crossover::/ . shift @tmp;
$strategist->require or die $!;
$self->_strategist($strategist->new(@tmp));
}
my $a = $self->_strategist->run($self);
$self->chromosomes( $a );
return;
}
#=======================================================================
sub _mutation {
my ($self) = @_;
unless($self->_mutator){
my $mutator = q/AI::Genetic::Pro::Mutation::/ . ucfirst(lc($self->type));
unless($mutator->require){
$mutator = q/AI::Genetic::Pro::Mutation::Listvector/;
$mutator->require;
}
$self->_mutator($mutator->new);
}
return $self->_mutator->run($self);
}
#=======================================================================
sub _save_history {
my @tmp;
if($_[0]->history){ @tmp = $_[0]->getAvgFitness; }
else { @tmp = (undef, undef, undef); }
push @{$_[0]->_history->[0]}, $tmp[0];
push @{$_[0]->_history->[1]}, $tmp[1];
push @{$_[0]->_history->[2]}, $tmp[2];
return 1;
}
#=======================================================================
sub inject {
my ($self, $candidates) = @_;
for(@$candidates){
push @{$self->chromosomes},
AI::Genetic::Pro::Chromosome->new_from_data($self->_translations, $self->type, $self->_package, $_, $self->_fix_range);
$self->_fitness->{$#{$self->chromosomes}} = $self->fitness()->($self, $self->chromosomes->[-1]);
}
$self->_strict( [ ] );
$self->population( $self->population + scalar( @$candidates ) );
return 1;
}
#=======================================================================
sub _state {
my ( $self ) = @_;
my @res;
if( $self->_package ){
@res = map {
[
${ tied( @{ $self->chromosomes->[ $_ ] } ) },
$self->_fitness->{ $_ },
]
} 0 .. $self->population - 1
}else{
@res = map {
[
$self->chromosomes->[ $_ ],
$self->_fitness->{ $_ },
]
} 0 .. $self->population - 1
}
return \@res;
}
#=======================================================================
sub evolve {
my ($self, $generations) = @_;
# generations must be defined
$generations ||= -1;
if($self->strict and $self->_strict){
for my $idx (0..$#{$self->chromosomes}){
croak(q/Chromosomes was modified outside the 'evolve' function!/) unless $self->chromosomes->[$idx] and $self->_strict->[$idx];
my @tmp0 = @{$self->chromosomes->[$idx]};
my @tmp1 = @{$self->_strict->[$idx]};
croak(qq/Chromosome was modified outside the 'evolve' function from "@tmp0" to "@tmp1"!/) unless compare(\@tmp0, \@tmp1);
}
}
lib/AI/Genetic/Pro.pm view on Meta::CPAN
This defines the size of the population, i.e. how many chromosomes
simultaneously exist at each generation.
=item -crossover
This defines the crossover rate. The fairest results are achieved with
crossover rate ~0.95.
=item -mutation
This defines the mutation rate. The fairest results are achieved with mutation
rate ~0.01.
=item -preserve
This defines injection of the bests chromosomes into a next generation. It causes a little slow down, however (very often) much better results are achieved. You can specify, how many chromosomes will be preserved, i.e.
-preserve => 1, # only one chromosome will be preserved
# or
-preserve => 9, # 9 chromosomes will be preserved
# and so on...
Attention! You cannot preserve more chromosomes than exist in your population.
=item -variable_length
This defines whether variable-length chromosomes are turned on (default off)
and a which types of mutation are allowed. See below.
=over 8
=item level 0
Feature is inactive (default). Example:
-variable_length => 0
# chromosomes (i.e. bitvectors)
0 1 0 0 1 1 0 1 1 1 0 1 0 1
0 0 1 1 0 1 1 1 1 0 0 1 1 0
0 1 1 1 0 1 0 0 1 1 0 1 1 1
0 1 0 0 1 1 0 1 1 1 1 0 1 0
# ...and so on
=item level 1
Feature is active, but chromosomes can varies B<only on the right side>, Example:
-variable_length => 1
# chromosomes (i.e. bitvectors)
0 1 0 0 1 1 0 1 1 1
0 0 1 1 0 1 1 1 1
0 1 1 1 0 1 0 0 1 1 0 1 1 1
0 1 0 0 1 1 0 1 1 1
# ...and so on
=item level 2
Feature is active and chromosomes can varies B<on the left side and on
the right side>; unwanted values/genes on the left side are replaced with C<undef>, ie.
-variable_length => 2
# chromosomes (i.e. bitvectors)
x x x 0 1 1 0 1 1 1
x x x x 0 1 1 1 1
x 1 1 1 0 1 0 0 1 1 0 1 1 1
0 1 0 0 1 1 0 1 1 1
# where 'x' means 'undef'
# ...and so on
In this situation returned chromosomes in an array context ($ga-E<gt>as_array($chromosome))
can have B<undef> values on the left side (only). In a scalar context each
undefined value is replaced with a single space. If You don't want to see
any C<undef> or space, just use C<as_array_def_only> and C<as_string_def_only>
instead of C<as_array> and C<as_string>.
=back
=item -parents
This defines how many parents should be used in a crossover.
=item -selection
This defines how individuals/chromosomes are selected to crossover. It expects an array reference listed below:
-selection => [ $type, @params ]
where type is one of:
=over 8
=item B<RouletteBasic>
Each individual/chromosome can be selected with probability proportional to its fitness.
=item B<Roulette>
First the best individuals/chromosomes are selected. From this collection
parents are selected with probability poportional to their fitness.
=item B<RouletteDistribution>
Each individual/chromosome has a portion of roulette wheel proportional to its
fitness. Selection is done with the specified distribution. Supported
distributions and parameters are listed below.
=over 12
=item C<-selection =E<gt> [ 'RouletteDistribution', 'uniform' ]>
Standard uniform distribution. No additional parameters are needed.
=item C<-selection =E<gt> [ 'RouletteDistribution', 'normal', $av, $sd ]>
Normal distribution, where C<$av> is average (default: size of population /2) and $C<$sd> is standard deviation (default: size of population).
=item C<-selection =E<gt> [ 'RouletteDistribution', 'beta', $aa, $bb ]>
I<Beta> distribution. The density of the beta is:
X^($aa - 1) * (1 - X)^($bb - 1) / B($aa , $bb) for 0 < X < 1.
C<$aa> and C<$bb> are set by default to number of parents.
B<Argument restrictions:> Both $aa and $bb must not be less than 1.0E-37.
=item C<-selection =E<gt> [ 'RouletteDistribution', 'binomial' ]>
Binomial distribution. No additional parameters are needed.
=item C<-selection =E<gt> [ 'RouletteDistribution', 'chi_square', $df ]>
lib/AI/Genetic/Pro.pm view on Meta::CPAN
Set/get number of parents in a crossover.
=item I<$ga>-E<gt>B<init>($args)
This method initializes the population with random individuals/chromosomes. It MUST be called before any call to C<evolve()>. It expects one argument, which depends on the type of individuals/chromosomes:
=over 4
=item B<bitvector>
For bitvectors, the argument is simply the length of the bitvector.
$ga->init(10);
This initializes a population where each individual/chromosome has 10 genes.
=item B<listvector>
For listvectors, the argument is an anonymous list of lists. The number of sub-lists is equal to the number of genes of each individual/chromosome. Each sub-list defines the possible string values that the corresponding gene can assume.
$ga->init([
[qw/red blue green/],
[qw/big medium small/],
[qw/very_fat fat fit thin very_thin/],
]);
This initializes a population where each individual/chromosome has 3 genes and each gene can assume one of the given values.
=item B<rangevector>
For rangevectors, the argument is an anonymous list of lists. The number of sub-lists is equal to the number of genes of each individual/chromosome. Each sub-list defines the minimum and maximum integer values that the corresponding gene can assume.
$ga->init([
[1, 5],
[0, 20],
[4, 9],
]);
This initializes a population where each individual/chromosome has 3 genes and each gene can assume an integer within the corresponding range.
=item B<combination>
For combination, the argument is an anonymous list of possible values of gene.
$ga->init( [ 'a', 'b', 'c' ] );
This initializes a population where each chromosome has 3 genes and each gene
is a unique combination of 'a', 'b' and 'c'. For example genes looks something
like that:
[ 'a', 'b', 'c' ] # gene 1
[ 'c', 'a', 'b' ] # gene 2
[ 'b', 'c', 'a' ] # gene 3
# ...and so on...
=back
=item I<$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
lib/AI/Genetic/Pro.pm view on Meta::CPAN
=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>($file)
Save the current state of the genetic algorithm to the specified file.
=item I<$ga>-E<gt>B<load>($file)
Load a state of the genetic algorithm from the specified file.
=item I<$ga>-E<gt>B<as_array>($chromosome)
In list context return an array representing the specified chromosome.
In scalar context return an reference to an array representing the specified
chromosome. If I<variable_length> is turned on and is set to level 2, an array
can have some C<undef> values. To get only C<not undef> values use
C<as_array_def_only> instead of C<as_array>.
=item I<$ga>-E<gt>B<as_array_def_only>($chromosome)
In list context return an array representing the specified chromosome.
In scalar context return an reference to an array representing the specified
chromosome. If I<variable_length> is turned off, this function is just an
alias for C<as_array>. If I<variable_length> is turned on and is set to
level 2, this function will return only C<not undef> values from chromosome.
See example below:
# -variable_length => 2, -type => 'bitvector'
my @chromosome = $ga->as_array($chromosome)
# @chromosome looks something like that
# ( undef, undef, undef, 1, 0, 1, 1, 1, 0 )
@chromosome = $ga->as_array_def_only($chromosome)
# @chromosome looks something like that
# ( 1, 0, 1, 1, 1, 0 )
=item I<$ga>-E<gt>B<as_string>($chromosome)
Return a string representation of the specified chromosome. See example below:
# -type => 'bitvector'
my $string = $ga->as_string($chromosome);
# $string looks something like that
# 1___0___1___1___1___0
# or
# -type => 'listvector'
$string = $ga->as_string($chromosome);
# $string looks something like that
# element0___element1___element2___element3...
Attention! If I<variable_length> is turned on and is set to level 2, it is
possible to get C<undef> values on the left side of the vector. In the returned
string C<undef> values will be replaced with B<spaces>. If you don't want
to see any I<spaces>, use C<as_string_def_only> instead of C<as_string>.
=item I<$ga>-E<gt>B<as_string_def_only>($chromosome)
Return a string representation of specified chromosome. If I<variable_length>
is turned off, this function is just alias for C<as_string>. If I<variable_length>
is turned on and is set to level 2, this function will return a string without
C<undef> values. See example below:
# -variable_length => 2, -type => 'bitvector'
my $string = $ga->as_string($chromosome);
# $string looks something like that
# ___ ___ ___1___1___0
$string = $ga->as_string_def_only($chromosome);
# $string looks something like that
# 1___1___0
=item I<$ga>-E<gt>B<as_value>($chromosome)
Return the score of the specified chromosome. The value of I<chromosome> is
calculated by the fitness function.
=back
=head1 SUPPORT
C<AI::Genetic::Pro> is still under development; however, it is used in many
production environments.
=head1 TODO
=over 4
=item Examples.
=item More tests.
=item More warnings about incorrect parameters.
=back
=head1 REPORTING BUGS
When reporting bugs/problems please include as much information as possible.
It may be difficult for me to reproduce the problem as almost every setup
is different.
A small script which yields the problem will probably be of help.
=head1 THANKS
Mario Roy for suggestions about efficiency.
Miles Gould for suggestions and some fixes (even in this documentation! :-).
Alun Jones for fixing memory leaks.
Tod Hagan for reporting a bug (rangevector values truncated to signed 8-bit quantities) and supplying a patch.
Randal L. Schwartz for reporting a bug in this documentation.
Maciej Misiak for reporting problems with C<combination> (and a bug in a PMX strategy).
LEONID ZAMDBORG for recommending the addition of variable-length chromosomes as well as supplying relevant code samples, for testing and at the end reporting some bugs.
Christoph Meissner for reporting a bug.
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