AI-NeuralNet-BackProp

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BackProp.pm  view on Meta::CPAN

#!/usr/bin/perl	

# $Id: BackProp.pm,v 0.89 2000/08/12 01:05:27 josiah Exp $
#
# Copyright (c) 2000  Josiah Bryan  USA
#
# See AUTHOR section in pod text below for usage and distribution rights.   
# See UPDATES section in pod text below for info on what has changed in this release.
#

BEGIN {
	$AI::NeuralNet::BackProp::VERSION = "0.89";
}

#
# name:   AI::NeuralNet::BackProp
#
# author: Josiah Bryan 
# date:   Tuesday August 15 2000
# desc:   A simple back-propagation, feed-foward neural network with
#		  learning implemented via a generalization of Dobbs rule and
#		  several principals of Hoppfield networks. 
# online: http://www.josiah.countystart.com/modules/AI/cgi-bin/rec.pl
#

package AI::NeuralNet::BackProp::neuron;
	
	use strict;
	
	# Dummy constructor
    sub new {
    	bless {}, shift
	}	
	
	# Rounds floats to ints
	sub intr  {
    	shift if(substr($_[0],0,4) eq 'AI::');
      	try   { return int(sprintf("%.0f",shift)) }
      	catch { return 0 }
	}
    
	
	# Receives input from other neurons. They must
	# be registered as a synapse of this neuron to effectively
	# input.
	sub input {
		my $self 	 =	shift;
		my $sid		 =	shift;
		my $value	 =	shift;
		
		# We simply weight the value sent by the neuron. The neuron identifies itself to us
		# using the code we gave it when it registered itself with us. The code is in $sid, 
		# (synapse ID) and we use that to track the weight of the connection.
		# This line simply multiplies the value by its weight and gets the integer from it.
		$self->{SYNAPSES}->{LIST}->[$sid]->{VALUE}	=	intr($value	*	$self->{SYNAPSES}->{LIST}->[$sid]->{WEIGHT});
		$self->{SYNAPSES}->{LIST}->[$sid]->{FIRED}	=	1;                                 
		$self->{SYNAPSES}->{LIST}->[$sid]->{INPUT}	=	$value;
		
		# Debugger
		AI::NeuralNet::BackProp::out1("\nRecieved input of $value, weighted to $self->{SYNAPSES}->{LIST}->[$sid]->{VALUE}, synapse weight is $self->{SYNAPSES}->{LIST}->[$sid]->{WEIGHT} (sid is $sid for $self).\n");
		AI::NeuralNet::BackProp::out1((($self->input_complete())?"All synapses have fired":"Not all synapses have fired"));
		AI::NeuralNet::BackProp::out1(" for $self.\n");
		
		# Check and see if all synapses have fired that are connected to this one.
		# If they have, then generate the output value for this synapse.
		$self->output() if($self->input_complete());
	}
	
	# Loops thru and outputs to every neuron that this
	# neuron is registered as synapse of.
	sub output {
		my $self	=	shift;
		my $size	=	$self->{OUTPUTS}->{SIZE} || 0;
		my $value	=	$self->get_output();
		for (0..$size-1) {
			AI::NeuralNet::BackProp::out1("Outputing to $self->{OUTPUTS}->{LIST}->[$_]->{PKG}, index $_, a value of $value with ID $self->{OUTPUTS}->{LIST}->[$_]->{ID}.\n");
			$self->{OUTPUTS}->{LIST}->[$_]->{PKG}->input($self->{OUTPUTS}->{LIST}->[$_]->{ID},$value);
		}
	}
	
	# Used internally by output().
	sub get_output {
		my $self		=	shift;
		my $size		=	$self->{SYNAPSES}->{SIZE} || 0;
		my $value		=	0;
		my $state		= 	0;
		my (@map,@weight);
	
	    # We loop through all the syanpses connected to this one and add the weighted
	    # valyes together, saving in a debugging list.
		for (0..$size-1) {
			$value	+=	$self->{SYNAPSES}->{LIST}->[$_]->{VALUE};
			$self->{SYNAPSES}->{LIST}->[$_]->{FIRED} = 0;
			
			$map[$_]=$self->{SYNAPSES}->{LIST}->[$_]->{VALUE};
			$weight[$_]=$self->{SYNAPSES}->{LIST}->[$_]->{WEIGHT};
		}
		                                              
		# Debugger
		AI::NeuralNet::BackProp::join_cols(\@map,5) if(($AI::NeuralNet::BackProp::DEBUG eq 3) || ($AI::NeuralNet::BackProp::DEBUG eq 2));
		AI::NeuralNet::BackProp::out2("Weights: ".join(" ",@weight)."\n");
		
		# Simply average the values and get the integer of the average.
		$state	=	intr($value/$size);
		
		# Debugger
		AI::NeuralNet::BackProp::out1("From get_output, value is $value, so state is $state.\n");
		
		# Possible future exapnsion for self excitation. Not currently used.
		$self->{LAST_VALUE}	=	$value;
		
		# Just return the $state
		return $state;
	}
	
	# Used by input() to check if all registered synapses have fired.
	sub input_complete {
		my $self		=	shift;
		my $size		=	$self->{SYNAPSES}->{SIZE} || 0;
		my $retvalue	=	1;
		
		# Very simple loop. Doesn't need explaning.
		for (0..$size-1) {
			$retvalue = 0 if(!$self->{SYNAPSES}->{LIST}->[$_]->{FIRED});
		}
		return $retvalue;
	}
	
	# Used to recursively adjust the weights of synapse input channeles
	# to give a desired value. Designed to be called via 
	# AI::NeuralNet::BackProp::NeuralNetwork::learn().
	sub weight	{                
		my $self		=	shift;
		my $ammount		=	shift;
		my $what		=	shift;
		my $size		=	$self->{SYNAPSES}->{SIZE} || 0;
		my $value;
		AI::NeuralNet::BackProp::out1("Weight: ammount is $ammount, what is $what with size at $size.\n");
		      
		# Now this sub is the main cog in the learning wheel. It is called recursively on 
		# each neuron that has been bad (given incorrect output.)
		for my $i (0..$size-1) {
			$value		=	$self->{SYNAPSES}->{LIST}->[$i]->{VALUE};

if(0) {
       
       		# Formula by Steve Purkis
       		# Converges very fast for low-value inputs. Has trouble converging on high-value
       		# inputs. Feel free to play and try to get to work for high values.
			my $delta	=	$ammount * ($what - $value) * $self->{SYNAPSES}->{LIST}->[$i]->{INPUT};
			$self->{SYNAPSES}->{LIST}->[$i]->{WEIGHT}  +=  $delta;
			$self->{SYNAPSES}->{LIST}->[$i]->{PKG}->weight($ammount,$what);
}
			
			# This formula in use by default is original by me (Josiah Bryan) as far as I know.
			
			# If it is equal, then don't adjust
			#
			### Disabled because this soemtimes causes 
			### infinte loops when learning with range limits enabled
			#
			#next if($value eq $what);
			
			# Adjust increment by the weight of the synapse of 
			# this neuron & apply direction delta
			my $delta = 
					$ammount * 
						($value<$what?1:-1) * 
							$self->{SYNAPSES}->{LIST}->[$i]->{WEIGHT};
			
			#print "($value,$what) delta:$delta\n";
			
			# Recursivly apply
			$self->{SYNAPSES}->{LIST}->[$i]->{WEIGHT}  +=  $delta;
			$self->{SYNAPSES}->{LIST}->[$i]->{PKG}->weight($ammount,$what);
			    
		}
	}
	
	# Registers some neuron as a synapse of this neuron.           
	# This is called exclusively by connect(), except for
	# in initalize_group() to connect the _map() package.
	sub register_synapse {
		my $self	=	shift;
		my $synapse	=	shift;
		my $sid		=	$self->{SYNAPSES}->{SIZE} || 0;
		$self->{SYNAPSES}->{LIST}->[$sid]->{PKG}		=	$synapse;
		$self->{SYNAPSES}->{LIST}->[$sid]->{WEIGHT}		=	1.00		if(!$self->{SYNAPSES}->{LIST}->[$sid]->{WEIGHT});
		$self->{SYNAPSES}->{LIST}->[$sid]->{FIRED}		=	0;       
		AI::NeuralNet::BackProp::out1("$self: Registering sid $sid with weight $self->{SYNAPSES}->{LIST}->[$sid]->{WEIGHT}, package $self->{SYNAPSES}->{LIST}->[$sid]->{PKG}.\n");
		$self->{SYNAPSES}->{SIZE} = ++$sid;
		return ($sid-1);
	}
	
	# Called via AI::NeuralNet::BackProp::NeuralNetwork::initialize_group() to 
	# form the neuron grids.
	# This just registers another synapes as a synapse to output to from this one, and
	# then we ask that synapse to let us register as an input connection and we
	# save the sid that the ouput synapse returns.
	sub connect {
		my $self	=	shift;
		my $to		=	shift;
		my $oid		=	$self->{OUTPUTS}->{SIZE} || 0;
		AI::NeuralNet::BackProp::out1("Connecting $self to $to at $oid...\n");
		$self->{OUTPUTS}->{LIST}->[$oid]->{PKG}	=	$to;
 		$self->{OUTPUTS}->{LIST}->[$oid]->{ID}	=	$to->register_synapse($self);
		$self->{OUTPUTS}->{SIZE} = ++$oid;
		return $self->{OUTPUTS}->{LIST}->[$oid]->{ID};
	}
1;
			 
package AI::NeuralNet::BackProp;
	
	use Benchmark;          
	use strict;
	
	# Returns the number of elements in an array ref, undef on error
	sub _FETCHSIZE {
		my $a=$_[0];
		my ($b,$x);
		return undef if(substr($a,0,5) ne "ARRAY");
		foreach $b (@{$a}) { $x++ };
		return $x;
	}

	# Debugging subs
	$AI::NeuralNet::BackProp::DEBUG  = 0;
	sub whowasi { (caller(1))[3] . '()' }
	sub debug { shift; $AI::NeuralNet::BackProp::DEBUG = shift || 0; } 
	sub out1  { print  shift() if ($AI::NeuralNet::BackProp::DEBUG eq 1) }
	sub out2  { print  shift() if (($AI::NeuralNet::BackProp::DEBUG eq 1) || ($AI::NeuralNet::BackProp::DEBUG eq 2)) }
	sub out3  { print  shift() if ($AI::NeuralNet::BackProp::DEBUG) }
	sub out4  { print  shift() if ($AI::NeuralNet::BackProp::DEBUG eq 4) }
	
	# Rounds a floating-point to an integer with int() and sprintf()
	sub intr  {
    	shift if(substr($_[0],0,4) eq 'AI::');
      	try   { return int(sprintf("%.0f",shift)) }
      	catch { return 0 }
	}
    
	# Used to format array ref into columns
	# Usage: 
	#	join_cols(\@array,$row_length_in_elements,$high_state_character,$low_state_character);
	# Can also be called as method of your neural net.
	# If $high_state_character is null, prints actual numerical values of each element.
	sub join_cols {
		no strict 'refs';
		shift if(substr($_[0],0,4) eq 'AI::'); 
		my $map		=	shift;
		my $break   =	shift;
		my $a		=	shift;
		my $b		=	shift;
		my $x;
		foreach my $el (@{$map}) { 
			my $str = ((int($el))?$a:$b);
			$str=$el."\0" if(!$a);
			print $str;
			$x++;
			if($x>$break-1) {
				print "\n";
				$x=0;
			}
		}
		print "\n";
	}
	
	# Returns percentage difference between all elements of two

BackProp.pm  view on Meta::CPAN

	sub run {
		my $self	=	shift;
		my $map		=	shift;
		my $x		=	0;
		$map = $self->{PARENT}->crunch($map) if($map == 0);
		return undef if(substr($map,0,5) ne "ARRAY");
		foreach my $el (@{$map}) {
			# Catch ourself if we try to run more inputs than neurons
			return $x if($x>$self->{PARENT}->{DIV}-1);
			
			# Here we add a small ammount of randomness to the network.
			# This is to keep the network from getting stuck on a 0 value internally.
			$self->{PARENT}->{NET}->[$x]->input(0,$el+(rand()*$self->{ramdom}));
			$x++;
		};
		# Incase we tried to run less inputs than neurons, run const 1 in extra neurons
		if($x<$self->{PARENT}->{DIV}) {
			for my $y ($x..$self->{PARENT}->{DIV}-1) {
				$self->{PARENT}->{NET}->[$y]->input(0,1);
			}
		}
		return $x;
	}
	
	
1;

# Internal output class. Not to be used directly.
package AI::NeuralNet::BackProp::_map;
	
	use strict;
	
	# Dummy constructor.
	sub new {
		bless { PARENT => $_[1] }, $_[0]
	}
	
	# Compliance with neuron interface
	sub weight {}
	
	# Compliance with neuron interface
	sub register_synapse {
		my $self	=	shift;		
		my $sid		=	$self->{REGISTRATION} || 0;
		$self->{REGISTRATION}	=	++$sid;
		$self->{RMAP}->{$sid-1} = 	$self->{PARENT}->{_tmp_synapse};
		return $sid-1;
	}
	
	# This acts just like a regular neuron by receiving
	# values from input synapes. Yet, unlike a regularr
	# neuron, it doesnt weight the values, just stores
	# them to be retrieved by a call to map().
	sub input  {
		no strict 'refs';             
		my $self	=	shift;
		my $sid		=	shift;
		my $value	=	shift;
		my $size	=	$self->{PARENT}->{DIV};
		my $flag	=	1;
		$self->{OUTPUT}->[$sid]->{VALUE}	=	$self->{PARENT}->intr($value);
		$self->{OUTPUT}->[$sid]->{FIRED}	=	1;
		
		AI::NeuralNet::BackProp::out1 "Received value $self->{OUTPUT}->[$sid]->{VALUE} and sid $sid, self $self.\n";
	}
	
	# Here we simply collect the value of every neuron connected to this
	# one from the layer below us and return an array ref to the final map..
	sub map {
		my $self	=	shift;
		my $size	=	$self->{PARENT}->{DIV};
		my $out		=	$self->{PARENT}->{OUT};
		my $divide  =	AI::NeuralNet::BackProp->intr($size/$out);
		my @map = ();
		my $value;
		AI::NeuralNet::BackProp::out1 "Num output neurons: $out, Input neurons: $size, Division: $divide\n";
		for(0..$out-1) {
			$value=0;
			for my $a (0..$divide-1) {
				$value += $self->{OUTPUT}->[($_*$divide)+$a]->{VALUE};
				AI::NeuralNet::BackProp::out1 "\$a is $a, index is ".(($_*$divide)+$a).", value is $self->{OUTPUT}->[($_*$divide)+$a]->{VALUE}\n";
			}
			$map[$_]	=	AI::NeuralNet::BackProp->intr($value/$divide);
			AI::NeuralNet::BackProp::out1 "Map position $_ is $map[$_] in @{[\@map]} with self set to $self.\n";
			$self->{OUTPUT}->[$_]->{FIRED}	=	0;
		}
		my $ret=\@map;
		return $self->{PARENT}->_range($ret);
	}
1;
			      
# load_pcx() wrapper package
package AI::NeuralNet::BackProp::PCX;

	# Called by load_pcx in AI::NeuralNet::BackProp;
	sub new {
		my $type	=	shift;
		my $self	=	{ 
			parent  => $_[0],
			file    => $_[1]
		};
		my (@a,@b)=load_pcx($_[1]);
		$self->{image}=\@a;
		$self->{palette}=\@b;
		bless \%{$self}, $type;
	}

	# Returns a rectangular block defined by an array ref in the form of
	# 		[$x1,$y1,$x2,$y2]
	# Return value is an array ref
	sub get_block {
		my $self	=	shift;
		my $ref		=	shift;
		my ($x1,$y1,$x2,$y2)	=	@{$ref};
		my @block	=	();
		my $count	=	0;
		for my $x ($x1..$x2-1) {
			for my $y ($y1..$y2-1) {
				$block[$count++]	=	$self->get($x,$y);
			}
		}
		return \@block;
	}
			
	# Returns pixel at $x,$y
	sub get {
		my $self	=	shift;
		my ($x,$y)  =	(shift,shift);
		return $self->{image}->[$y*320+$x];
	}
	
	# Returns array of (r,g,b) value from palette index passed
	sub rgb {
		my $self	=	shift;
		my $color	=	shift;
		return ($self->{palette}->[$color]->{red},$self->{palette}->[$color]->{green},$self->{palette}->[$color]->{blue});
	}
		
	# Returns mean of (rgb) value of palette index passed
	sub avg {
		my $self	=	shift;
		my $color	=	shift;
		return $self->{parent}->intr(($self->{palette}->[$color]->{red}+$self->{palette}->[$color]->{green}+$self->{palette}->[$color]->{blue})/3);
	}
	



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