public class KozaNodeSelector extends java.lang.Object implements GPNodeSelector
The KozaNodeSelector chooses by probability between these four situations. Then, based on the situation it has picked, it selects either a random terminal, nonterminal, root, or arbitrary node from the tree and returns it.
As the selector picks a node, it builds up some statistics information which makes it able to pick a little faster in subsequent passes. Thus if you want to reuse this selector on another tree, you need to call reset() first.
Parameters
base.terminals 0.0 <= double <= 1.0, nonterminals + terminals + root <= 1.0 |
(the probability we must pick a terminal) |
base.nonterminals 0.0 <= double <= 1.0, nonterminals + terminals + root <= 1.0 |
(the probability we must pick a nonterminal if possible) |
base.root 0.0 <= double <= 1.0, nonterminals + terminals + root <= 1.0 |
(the probability we must pick the root) |
DefaultBase
gp.koza.ns
Modifier and Type | Field and Description |
---|---|
int |
nodes
The number of nodes in the tree, -1 if unknown.
|
double |
nonterminalProbability
The probability a nonterminal must be chosen.
|
int |
nonterminals
The number of nonterminals in the tree, -1 if unknown.
|
static java.lang.String |
P_NODESELECTOR |
static java.lang.String |
P_NONTERMINAL_PROBABILITY |
static java.lang.String |
P_ROOT_PROBABILITY |
static java.lang.String |
P_TERMINAL_PROBABILITY |
double |
rootProbability
The probability the root must be chosen
|
double |
terminalProbability
The probability a terminal must be chosen
|
int |
terminals
The number of terminals in the tree, -1 if unknown.
|
Constructor and Description |
---|
KozaNodeSelector() |
Modifier and Type | Method and Description |
---|---|
java.lang.Object |
clone()
Creates a new individual cloned from a prototype,
and suitable to begin use in its own evolutionary
context.
|
Parameter |
defaultBase()
Returns the default base for this prototype.
|
GPNode |
pickNode(EvolutionState s,
int subpopulation,
int thread,
GPIndividual ind,
GPTree tree)
Picks a node at random from tree and returns it.
|
void |
reset()
Resets the Node Selector before a new series of pickNode()
if need be.
|
void |
setup(EvolutionState state,
Parameter base)
Sets up the object by reading it from the parameters stored
in state, built off of the parameter base base.
|
public static final java.lang.String P_NODESELECTOR
public static final java.lang.String P_TERMINAL_PROBABILITY
public static final java.lang.String P_NONTERMINAL_PROBABILITY
public static final java.lang.String P_ROOT_PROBABILITY
public double rootProbability
public double terminalProbability
public double nonterminalProbability
public int nonterminals
public int terminals
public int nodes
public Parameter defaultBase()
Prototype
defaultBase
in interface Prototype
public java.lang.Object clone()
Prototype
Typically this should be a full "deep" clone. However, you may share certain elements with other objects rather than clone hem, depending on the situation:
Implementations.
public Object clone()
{
try
{
return super.clone();
}
catch ((CloneNotSupportedException e)
{ throw new InternalError(); } // never happens
}
public Object clone()
{
try
{
MyObject myobj = (MyObject) (super.clone());
// put your deep-cloning code here...
}
catch ((CloneNotSupportedException e)
{ throw new InternalError(); } // never happens
return myobj;
}
public Object clone()
{
MyObject myobj = (MyObject) (super.clone());
// put your deep-cloning code here...
return myobj;
}
public void setup(EvolutionState state, Parameter base)
Prototype
For prototypes, setup(...) is typically called once for the prototype instance; cloned instances do not receive the setup(...) call. setup(...) may be called more than once; the only guarantee is that it will get called at least once on an instance or some "parent" object from which it was ultimately cloned.
public void reset()
GPNodeSelector
reset
in interface GPNodeSelector
public GPNode pickNode(EvolutionState s, int subpopulation, int thread, GPIndividual ind, GPTree tree)
GPNodeSelector
pickNode
in interface GPNodeSelector