AI-NeuralNet-Mesh

 view release on metacpan or  search on metacpan

Mesh.pm  view on Meta::CPAN

	# net at least TWICE on the data set, because the first 
	# time the ramp() function searches for the top value in
	# the inputs, and therefore, results could flucuate.
	# The second learning cycle guarantees more accuracy.
	#
	sub ramp {
		my $r=shift||1;my $t=($r<2)?0:-1;
		sub{$_[1]->{t}=$_[0]if($_[0]>$_[1]->{t});$_[0]/$_[1]->{t}*$r-$b}
	}

	# Self explanitory, pretty much. $threshold is used to decide if an input 
	# is true or false (1 or 0). If an input is below $threshold, it is false.
	sub and_gate {
		my $threshold = shift || 0.5;
		sub {
			my $sum  = shift;
			my $self = shift;
			for my $x (0..$self->{_inputs_size}-1) { return $self->{_parent}->{const} if!$self->{_inputs}->[$x]->{value}<$threshold }
			return $sum/$self->{_inputs_size};
		}
	}

Mesh.pm  view on Meta::CPAN

then learn() will not return until it gets an exact match for the desired result OR it
reaches $maximum_iterations.

$degrade_increment_flag is a simple flag used to allow/dissalow increment degrading
during learning based on a product of the error difference with several other factors.
$degrade_increment_flag is off by default. Setting $degrade_increment_flag to a true
value turns increment degrading on. 

In previous module releases $degrade_increment_flag was not used, as increment degrading
was always on. In this release I have looked at several other network types as well
as several texts and decided that it would be better to not use increment degrading. The
option is still there for those that feel the inclination to use it. I have found some areas
that do need the degrade flag to work at a faster speed. See test.pl for an example. If
the degrade flag wasn't in test.pl, it would take a very long time to learn.



=item $net->learn_set(\@set, [ options ]);

This takes the same options as learn() (learn_set() uses learn() internally) 
and allows you to specify a set to learn, rather than individual patterns. 

Mesh.pm  view on Meta::CPAN

time the ramp() function searches for the top value in
the inputs, and therefore, results could flucuate.
The second learning cycle guarantees more accuracy.

No code to show here, as it is almost exactly the same as range().


=item and_gate($threshold);

Self explanitory, pretty much. This turns the node into a basic AND gate.
$threshold is used to decide if an input is true or false (1 or 0). If 
an input is below $threshold, it is false. $threshold defaults to 0.5.

You can get this into your namespace with the ':acts' export 
tag as so:
	
	use AI::NeuralNet::Mesh ':acts';

Let's look at the code real quick, as it shows how to get at the indivudal
input connections:

examples/ex_wine.pl  view on Meta::CPAN

		
        This script uses the data that is the results of a chemical analysis 
        of wines grown in the same region in Italy but derived from three
	    different cultivars. The analysis determined the quantities 
	    of 13 constituents found in each of the three types of wines. 

		The inputs of the net represent 13 seperate attributes
		of the wine's chemical analysis, as follows:
		
		 	1)  Alcohol
		 	2)  Malic acid
		 	3)  Ash
			4)  Alcalinity of ash  
		 	5)  Magnesium
			6)  Total phenols
		 	7)  Flavanoids
		 	8)  Nonflavanoid phenols
		 	9)  Proanthocyanins
			10) Color intensity
		 	11) Hue
		 	12) OD280/OD315 of diluted wines

mesh.htm  view on Meta::CPAN

actual results and desired results falls below $maximum_allowable_percentage_of_error.
If you do not include 'error', or $maximum_allowable_percentage_of_error is set to -1,
then <A HREF="#item_learn"><CODE>learn()</CODE></A> will not return until it gets an exact match for the desired result OR it
reaches $maximum_iterations.</P>
<P>$degrade_increment_flag is a simple flag used to allow/dissalow increment degrading
during learning based on a product of the error difference with several other factors.
$degrade_increment_flag is off by default. Setting $degrade_increment_flag to a true
value turns increment degrading on.</P>
<P>In previous module releases $degrade_increment_flag was not used, as increment degrading
was always on. In this release I have looked at several other network types as well
as several texts and decided that it would be better to not use increment degrading. The
option is still there for those that feel the inclination to use it. I have found some areas
that do need the degrade flag to work at a faster speed. See test.pl for an example. If
the degrade flag wasn't in test.pl, it would take a very long time to learn.</P>
<P></P>
<DT><STRONG><A NAME="item_learn_set">$net-&gt;learn_set(\@set, [ options ]);</A></STRONG><BR>
<DD>
This takes the same options as <A HREF="#item_learn"><CODE>learn()</CODE></A> (learn_set() uses <A HREF="#item_learn"><CODE>learn()</CODE></A> internally) 
and allows you to specify a set to learn, rather than individual patterns. 
A dataset is an array refrence with at least two elements in the array, 
each element being another array refrence (or now, a scalar string). For 

mesh.htm  view on Meta::CPAN

<P>Note: when using a <A HREF="#item_ramp"><CODE>ramp()</CODE></A> activatior, train the
net at least TWICE on the data set, because the first 
time the <A HREF="#item_ramp"><CODE>ramp()</CODE></A> function searches for the top value in
the inputs, and therefore, results could flucuate.
The second learning cycle guarantees more accuracy.</P>
<P>No code to show here, as it is almost exactly the same as range().</P>
<P></P>
<DT><STRONG><A NAME="item_and_gate">and_gate($threshold);</A></STRONG><BR>
<DD>
Self explanitory, pretty much. This turns the node into a basic AND gate.
$threshold is used to decide if an input is true or false (1 or 0). If 
an input is below $threshold, it is false. $threshold defaults to 0.5.
<P>You can get this into your namespace with the ':acts' export 
tag as so:
</P>
<PRE>
        use AI::NeuralNet::Mesh ':acts';</PRE>
<P>Let's look at the code real quick, as it shows how to get at the indivudal
input connections:</P>
<PRE>
        = line 1 =      sub {



( run in 0.465 second using v1.01-cache-2.11-cpan-de7293f3b23 )