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	$net->activation(4,range(@numbers));
	$net->activation(4,range(6,15,26,106,28,3));

Note: when using a range() activatior, train the
net TWICE on the data set, because the first time
the range() function searches for the top value in
the inputs, and therefore, results could flucuate.
The second learning cycle guarantees more accuracy.

The actual code that implements the range closure is
a bit convulted, so I will expand on it here as a simple
tutorial for custom activation functions.

	= line 1 = 	sub {
	= line 2 =		my @values = ( 6..10 );
	= line 3 =		my $sum   = shift;
	= line 4 =		my $self  = shift;
	= line 5 =		$self->{top_value}=$sum if($sum>$self->{top_value});
	= line 6 =		my $index = intr($sum/$self->{top_value}*$#values);
	= line 7 =		return $values[$index];
	= line 8 =	}

Now, the actual function fits in one line of code, but I expanded it a bit
here. Line 1 creates our array of allowed output values. Lines two and
three grab our parameters off the stack which allow us access to the
internals of this node. Line 5 checks to see if the sum output of this
node is higher than any previously encountered, and, if so, it sets
the marker higher. This also shows that you can use the $self refrence
to maintain information across activations. This technique is also used
in the ramp() activator. Line 6 computes the index into the allowed
values array by first scaling the $sum to be between 0 and 1 and then
expanding it to fit smoothly inside the number of elements in the array. Then
we simply round to an integer and pluck that index from the array and
use it as the output value for that node. 

See? It's not that hard! Using custom activation functions, you could do
just about anything with the node that you want to, since you have
access to the node just as if you were a blessed member of that node's object.


=item ramp($r);

mesh.htm  view on Meta::CPAN

seperated list of values as parameters:</P>
<PRE>
        $net-&gt;activation(4,range(@numbers));
        $net-&gt;activation(4,range(6,15,26,106,28,3));</PRE>
<P>Note: when using a <A HREF="#item_range"><CODE>range()</CODE></A> activatior, train the
net TWICE on the data set, because the first time
the <A HREF="#item_range"><CODE>range()</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>The actual code that implements the range closure is
a bit convulted, so I will expand on it here as a simple
tutorial for custom activation functions.</P>
<PRE>
        = line 1 =      sub {
        = line 2 =              my @values = ( 6..10 );
        = line 3 =              my $sum   = shift;
        = line 4 =              my $self  = shift;
        = line 5 =              $self-&gt;{top_value}=$sum if($sum&gt;$self-&gt;{top_value});
        = line 6 =              my $index = intr($sum/$self-&gt;{top_value}*$#values);
        = line 7 =              return $values[$index];
        = line 8 =      }</PRE>
<P>Now, the actual function fits in one line of code, but I expanded it a bit
here. Line 1 creates our array of allowed output values. Lines two and
three grab our parameters off the stack which allow us access to the
internals of this node. Line 5 checks to see if the sum output of this
node is higher than any previously encountered, and, if so, it sets
the marker higher. This also shows that you can use the $self refrence
to maintain information across activations. This technique is also used
in the <A HREF="#item_ramp"><CODE>ramp()</CODE></A> activator. Line 6 computes the index into the allowed
values array by first scaling the $sum to be between 0 and 1 and then
expanding it to fit smoothly inside the number of elements in the array. Then
we simply round to an integer and pluck that index from the array and
use it as the output value for that node.</P>
<P>See? It's not that hard! Using custom activation functions, you could do
just about anything with the node that you want to, since you have
access to the node just as if you were a blessed member of that node's object.</P>
<P></P>
<DT><STRONG><A NAME="item_ramp">ramp($r);</A></STRONG><BR>
<DD>
<A HREF="#item_ramp"><CODE>ramp()</CODE></A> preforms smooth ramp activation between 0 and 1 if $r is 1, 
or between -1 and 1 if $r is 2. $r defaults to 1.