AI-ANN

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gpl.txt  view on Meta::CPAN

  Each version is given a distinguishing version number.  If the
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by the Free Software Foundation.

  If the Program specifies that a proxy can decide which future
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to choose that version for the Program.

  Later license versions may give you additional or different
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later version.

  15. Disclaimer of Warranty.

lib/AI/ANN/Evolver.pm  view on Meta::CPAN

				if (abs($weight) < $self->{'mutation_amount'}) {
					if (rand() < $self->{'kill_link_chance'}) {
						$weight = undef;
					}
				}
			} else {
				if (rand() < $self->{'add_link_chance'}) {
					$weight = rand() * $self->{'mutation_amount'};
					# We want to Do The Right Thing. Here, that means to 
					# detect whether the user is using weights in (0, x), and
					# if so make sure we don't accidentally give them a 
					# negative weight, because that will become 0.000001. 
					# Instead, we'll generate a positive only value at first 
					# (it's easier) and then, if the user will accept negative 
					# weights, we'll let that happen.
					if ($self->{'min_value'} < 0) {
						($weight *= 2) -= $self->{'mutation_amount'};
					}
					# Of course, we have to check to be sure...
					if ($weight > $self->{'max_value'}) { 
						$weight = $self->{'max_value'};

lib/AI/ANN/Evolver.pm  view on Meta::CPAN

					if (rand() < $self->{'kill_link_chance'}) {
						$weight = undef;
					}
				}

			} else {
				if (rand() < $self->{'add_link_chance'}) {
					$weight = rand() * $self->{'mutation_amount'};
					# We want to Do The Right Thing. Here, that means to 
					# detect whether the user is using weights in (0, x), and
					# if so make sure we don't accidentally give them a 
					# negative weight, because that will become 0.000001. 
					# Instead, we'll generate a positive only value at first 
					# (it's easier) and then, if the user will accept negative 
					# weights, we'll let that happen.
					if ($self->{'min_value'} < 0) {
						($weight *= 2) -= $self->{'mutation_amount'};
					}
					# Of course, we have to check to be sure...
					if ($weight > $self->{'max_value'}) { 
						$weight = $self->{'max_value'};

lib/AI/ANN/Evolver.pm  view on Meta::CPAN

kill_link_chance is the chance that, during a mutate() call, each pair of 
	connected neurons with a weight less than mutation_amount or each 
	neuron => input pair with a weight less than mutation_amount will be
	disconnected. If add_link_chance is zero, this should also be zero, or 
	your network will just fizzle out.
sub_crossover_chance is the chance that, during a crossover() call, each 
	neuron will, rather than being inherited fully from each parent, have 
	each element within it be inherited individually.
min_value is the smallest acceptable weight. It must be less than or equal to 
	zero. If a value would be decremented below min_value, it will instead 
	become an epsilon above min_value. This is so that we don't accidentally 
	set a weight to zero, thereby killing the link.
max_value is the largest acceptable weight. It must be greater than zero.
gaussian_tau and gaussian_tau_prime are the terms to the gaussian mutation 
    method. They are coderefs which accept one parameter, n, the number of
    non-zero-weight inputs to the given neuron.

=head2 crossover

$evolver->crossover( $network1, $network2 )