ec.app.lawnmower.func
Class LawnERC

java.lang.Object
  ec.gp.GPNode
      ec.gp.ERC
          ec.app.lawnmower.func.LawnERC

All Implemented Interfaces:

GPNodeParent, Prototype, Setup, java.io.Serializable, java.lang.Cloneable

public class LawnERC
extends ERC

Version:

1.0

Author:

Sean Luke

See Also:

Serialized Form

Field Summary

int	maxx
int	maxy
int	x
int	y

Fields inherited from class ec.gp.ERC

ERC_PREFIX

Fields inherited from class ec.gp.GPNode

argposition, children, constraints, GPNODEPRINTTAB, MAXPRINTBYTES, NODESEARCH_ALL, NODESEARCH_CUSTOM, NODESEARCH_NONTERMINALS, NODESEARCH_TERMINALS, P_NODE, P_NODECONSTRAINTS, parent, REPLACEMENT_CHAR, SITUATION_MUTATION, SITUATION_NEWIND

Constructor Summary

LawnERC()

Method Summary

boolean	decode(DecodeReturn dret) Decodes data into the ERC from dret.
java.lang.String	encode() Encodes data from the ERC, using ec.util.Code.
void	eval(EvolutionState state, int thread, GPData input, ADFStack stack, GPIndividual individual, Problem problem) Evaluates the node with the given thread, state, individual, problem, and stack.
java.lang.String	name() Returns the lowercase "name" of this ERC function class, some simple, short name which distinguishes this class from other ERC function classes you're using.
boolean	nodeEquals(GPNode node) Implement this to do ERC-to-ERC comparisons.
int	nodeHashCode() Implement this to hash ERCs, along with other nodes, in such a way that two "equal" ERCs will usually hash to the same value.
void	readNode(EvolutionState state, java.io.DataInput dataInput) To successfully read from a DataOutput, you must override this to read your specific ERC data in.
void	resetNode(EvolutionState state, int thread) Remember to override this to randomize your ERC after it has been cloned.
void	setup(EvolutionState state, Parameter base) Sets up a prototypical GPNode with those features all nodes of that prototype share, and nothing more.
java.lang.String	toStringForHumans() You might want to override this to return a special human-readable version of the erc value; otherwise this defaults to toString(); This should be something that resembles a LISP atom.
void	writeNode(EvolutionState state, java.io.DataOutput dataOutput) To successfully write to a DataOutput, you must override this to write your specific ERC data out.

Methods inherited from class ec.gp.ERC

checkConstraints, mutateERC, readNode, toString

Methods inherited from class ec.gp.GPNode

atDepth, clone, cloneReplacing, cloneReplacing, cloneReplacing, cloneReplacingAtomic, cloneReplacingAtomic, cloneReplacingNoSubclone, constraints, contains, defaultBase, depth, errorInfo, lightClone, makeCTree, makeLatexTree, nodeEquivalentTo, nodeInPosition, numNodes, numNodes, parentType, printNode, printNode, printNodeForHumans, printRootedTree, printRootedTree, printRootedTreeForHumans, readRootedTree, readRootedTree, replaceWith, rootedTreeEquals, rootedTreeHashCode, rootParent, swapCompatibleWith, toStringForError, writeRootedTree

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

maxx

public int maxx

maxy

public int maxy

x

public int x

y

public int y

Constructor Detail

LawnERC

public LawnERC()

Method Detail

setup

public void setup(EvolutionState state,
                  Parameter base)

Description copied from class: GPNode

Sets up a prototypical GPNode with those features all nodes of that prototype share, and nothing more. So no filled-in children, no argposition, no parent. Yet. This must be called after the GPTypes and GPNodeConstraints have been set up. Presently they're set up in GPInitializer, which gets called before this does, so we're safe. You should override this if you need to load some special features on a per-function basis. Note that base hangs off of a function set, so this method may get called for different instances in the same GPNode class if they're being set up as prototypes for different GPFunctionSets. If you absolutely need some global base, then you should use something hanging off of GPDefaults.base(). The ultimate caller of this method must guarantee that he will eventually call state.output.exitIfErrors(), so you can freely use state.output.error instead of state.output.fatal(), which will help a lot.

Specified by:

setup in interface Prototype

Specified by:

setup in interface Setup

Overrides:

setup in class GPNode

resetNode

public void resetNode(EvolutionState state,
                      int thread)

Description copied from class: ERC

Remember to override this to randomize your ERC after it has been cloned. The prototype will not ever receive this method call.

Specified by:

resetNode in class ERC

nodeHashCode

public int nodeHashCode()

Description copied from class: ERC

Implement this to hash ERCs, along with other nodes, in such a way that two "equal" ERCs will usually hash to the same value.

Specified by:

nodeHashCode in class ERC

nodeEquals

public boolean nodeEquals(GPNode node)

Description copied from class: ERC

Implement this to do ERC-to-ERC comparisons.

Specified by:

nodeEquals in class ERC

readNode

public void readNode(EvolutionState state,
                     java.io.DataInput dataInput)
              throws java.io.IOException

Description copied from class: ERC

To successfully read from a DataOutput, you must override this to read your specific ERC data in. The default implementation issues a fatal error.

Overrides:

readNode in class ERC

Throws:

java.io.IOException

writeNode

public void writeNode(EvolutionState state,
                      java.io.DataOutput dataOutput)
               throws java.io.IOException

Description copied from class: ERC

To successfully write to a DataOutput, you must override this to write your specific ERC data out. The default implementation issues a fatal error.

Overrides:

writeNode in class ERC

Throws:

java.io.IOException

encode

public java.lang.String encode()

Description copied from class: ERC

Encodes data from the ERC, using ec.util.Code.

Specified by:

encode in class ERC

decode

public boolean decode(DecodeReturn dret)

Description copied from class: ERC

Decodes data into the ERC from dret. Return true if you sucessfully decoded, false if you didn't. Don't increment dret.pos's value beyond exactly what was needed to decode your ERC. If you fail to decode, you should make sure that the position and data in the dret are exactly as they were originally.

Specified by:

decode in class ERC

name

public java.lang.String name()

Description copied from class: ERC

Returns the lowercase "name" of this ERC function class, some simple, short name which distinguishes this class from other ERC function classes you're using. If you have only one ERC function class, you can just return "". Whatever the name is, it should generally only have letters, numbers, or hyphens or underscores in it. No whitespace or other characters.

Specified by:

name in class ERC

toStringForHumans

public java.lang.String toStringForHumans()

Description copied from class: ERC

You might want to override this to return a special human-readable version of the erc value; otherwise this defaults to toString(); This should be something that resembles a LISP atom. If a simple number or other object won't suffice, you might use something that begins with ERC_PREFIX + name() + [ + ... + ]

Overrides:

toStringForHumans in class ERC

eval

public void eval(EvolutionState state,
                 int thread,
                 GPData input,
                 ADFStack stack,
                 GPIndividual individual,
                 Problem problem)

Description copied from class: GPNode

Evaluates the node with the given thread, state, individual, problem, and stack. Your random number generator will be state.random[thread]. The node should, as appropriate, evaluate child nodes with these same items passed to eval(...).

About input: input is special; it is how data is passed between parent and child nodes. If children "receive" data from their parent node when it evaluates them, they should receive this data stored in input. If (more likely) the parent "receives" results from its children, it should pass them an input object, which they'll fill out, then it should check this object for the returned value.

A tree is typically evaluated by dropping a GPData into the root. When the root returns, the resultant input should hold the return value.

In general, you should not be creating new GPDatas. If you think about it, in most conditions (excepting ADFs and ADMs) you can use and reuse input for most communications purposes between parents and children.

So, let's say that your GPNode function implements the boolean AND function, and expects its children to return return boolean values (as it does itself). You've implemented your GPData subclass to be, uh, BooleanData, which looks like

public class BooleanData extends GPData 
    {
    public boolean result;
    public GPData copyTo(GPData gpd)
      {
      ((BooleanData)gpd).result = result;
      }
    }

...so, you might implement your eval(...) function as follows:

public void eval(final EvolutionState state,
                     final int thread,
                     final GPData input,
                     final ADFStack stack,
                     final GPIndividual individual,
                     final Problem problem
    {
    BooleanData dat = (BooleanData)input;
    boolean x;

    // evaluate the first child
    children[0].eval(state,thread,input,stack,individual,problem);
  
    // store away its result
    x = dat.result;

    // evaluate the second child
    children[1].eval(state,thread,input,stack,individual,problem);

    // return (in input) the result of the two ANDed

    dat.result = dat.result && x;
    return;
    }
        

Specified by:

eval in class GPNode