/*
Copyright 2006 by Sean Luke
Licensed under the Academic Free License version 3.0
See the file "LICENSE" for more information
*/
package ec.gp;
import ec.*;
import ec.util.*;
/* GPNodeConstraints.java
*
* Created: Fri Aug 27 17:40:40 1999
* By: Sean Luke
*
*/
/**
* A GPNodeConstraints is a Clique which defines constraint information
* common to many different GPNode functions, namely return types,
* child types, and number of children.
* GPNodeConstraints have unique names by which
* they are identified.
*
* In adding new things to GPNodeConstraints, you should ask yourself
* the following questions: first, is this something that takes up too
* much memory to store in GPNodes themselves? second, is this something
* that needs to be accessed very rapidly, so cannot be implemented
* as a method call in a GPNode? third, can this be shared among
* different GPNodes, even ones representing different functions?
Parameters
base.size
int >= 1 |
(number of node constraints) |
base.n.name
String |
(name of node constraint n) |
base.n.returns
String |
(return type for node constraint n) |
base.n.size
int >= 1 |
(number of child arguments for node constraint n) |
base.n.child.m
String |
(name of type for child argument m of node constraint n) |
base.prob
float >= 0.0 |
(auxillary probability of selection -- used by ec.gp.build.PTC1 and ec.gp.build.PTC2) |
* @author Sean Luke
* @version 1.0
*/
public class GPNodeConstraints implements Clique
{
public static final int SIZE_OF_BYTE = 256;
public final static String P_NAME = "name";
public final static String P_RETURNS = "returns";
public final static String P_CHILD = "child";
public final static String P_SIZE = "size";
public final static String P_PROBABILITY = "prob";
public final static float DEFAULT_PROBABILITY = 1.0f;
/** Probability of selection -- an auxillary measure mostly used by PTC1/PTC2
right now */
public float probabilityOfSelection;
/** The byte value of the constraints -- we can only have 256 of them */
public byte constraintNumber;
/** The return type for a GPNode */
public GPType returntype;
/** The children types for a GPNode */
public GPType[] childtypes;
/** The name of the GPNodeConstraints object -- this is NOT the
name of the GPNode */
public String name;
public String toString() { return name; }
/** A little memory optimization: if GPNodes have no children, they are welcome to
use share this zero-sized array as their children array. */
public GPNode zeroChildren[] = new GPNode[0];
/** This must be called after the GPTypes have been set up. */
public final void setup(final EvolutionState state, final Parameter base)
{
// What's my name?
name = state.parameters.getString(base.push(P_NAME),null);
if (name==null)
state.output.fatal("No name was given for this node constraints.",
base.push(P_NAME));
// Register me
GPNodeConstraints old_constraints = (GPNodeConstraints)(((GPInitializer)state.initializer).nodeConstraintRepository.put(name,this));
if (old_constraints != null)
state.output.fatal("The GP node constraint \"" + name + "\" has been defined multiple times.", base.push(P_NAME));
// What's my return type?
String s = state.parameters.getString(base.push(P_RETURNS),null);
if (s==null)
state.output.fatal("No return type given for the GPNodeConstraints " + name, base.push(P_RETURNS));
returntype = GPType.typeFor(s,state);
// Load probability of selection
if (state.parameters.exists(base.push(P_PROBABILITY),null))
{
float f = state.parameters.getFloat(base.push(P_PROBABILITY),null,0);
if (f < 0)
state.output.fatal("The probability of selection is < 0, which is not valid.",base.push(P_PROBABILITY),null);
probabilityOfSelection = f;
}
else probabilityOfSelection = DEFAULT_PROBABILITY;
// How many child types do I have?
int x = state.parameters.getInt(base.push(P_SIZE),null,0);
if (x < 0)
state.output.fatal("The number of children types for the GPNodeConstraints " + name + " must be >= 0.", base.push(P_SIZE));
childtypes = new GPType[x];
Parameter p = base.push(P_CHILD);
// Load my children
for (x=0;x