ec.gp
Class ADFContext

java.lang.Object
  |
  +--ec.gp.ADFContext

public class ADFContext
extends java.lang.Object
implements Prototype

ADFContext is the object pushed onto an ADF stack which represents the current context of an ADM or ADF function call, that is, how to get the argument values that argument_terminals need to return.

adf contains the relevant ADF/ADM node. If it's an ADF function call, then arguments[] contains the evaluated arguments to the ADF. If it's an ADM function call, then arguments[] is set to false.

You set up the ADFContext object for a given ADF or ADM node with the prepareADF(...) and prepareADM(...) functions.

To evaluate an argument number from an ADFContext, call evaluate(...), and the results are evaluated and copied into input.

Parameters
base.data
classname, inherits and != ec.GPData
(the class for the ADFContext's basic GPData type -- typically this is the same as GPProblem's GPData type)

Default Base
gp.adf-context

Parameter bases
base.data
(the ADFContext's basic GPData type)

See Also:
Serialized Form

Field Summary
 ADF adf
          The ADF/ADM node proper
 GPData arg_proto
          A prototypical GPData node.
 GPData[] arguments
          An array of GPData nodes (none of the null, when it's used) holding an ADF's arguments' return results
static int INITIAL_ARGUMENT_SIZE
           
static java.lang.String P_ADFCONTEXT
           
static java.lang.String P_DATA
           
 
Constructor Summary
ADFContext()
           
 
Method Summary
 Parameter defaultBase()
          Returns the default base for this prototype.
 void evaluate(EvolutionState state, int thread, GPData input, ADFStack stack, GPIndividual individual, Problem problem, int argument)
          Evaluates the argument number in the current context
 void prepareADF(ADF a)
          Increases arguments to accommodate space if necessary.
 void prepareADM(ADM a)
          Sets adf to a
 java.lang.Object protoClone()
          Creates a new individual cloned from a prototype, and suitable to begin use in its own evolutionary context.
 java.lang.Object protoCloneSimple()
          This should be implemented in a the top-level Prototype ONLY; in fact, it should probably be declared final.
 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.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

P_DATA

public static final java.lang.String P_DATA

P_ADFCONTEXT

public static final java.lang.String P_ADFCONTEXT

INITIAL_ARGUMENT_SIZE

public static final int INITIAL_ARGUMENT_SIZE

adf

public ADF adf
The ADF/ADM node proper

arg_proto

public GPData arg_proto
A prototypical GPData node.

arguments

public GPData[] arguments
An array of GPData nodes (none of the null, when it's used) holding an ADF's arguments' return results
Constructor Detail

ADFContext

public ADFContext()
Method Detail

defaultBase

public Parameter defaultBase()
Description copied from interface: Prototype
Returns the default base for this prototype. This should generally be implemented by building off of the static base() method on the DefaultsForm object for the prototype's package. This should be callable during setup(...).
Specified by:
defaultBase in interface Prototype

protoClone

public java.lang.Object protoClone()
                            throws java.lang.CloneNotSupportedException
Description copied from interface: Prototype
Creates a new individual cloned from a prototype, and suitable to begin use in its own evolutionary context.

The question here is whether or not this means to perform a "deep" or "light" ("shallow") clone, or something in-between. You may need to deep-clone parts of your object rather than simply copying their references, depending on the situation:

Implementations.

If you know that your superclasses will never change their protoClone() implementations, you might try inlining them in your overridden protoClone() method. But this is dangerous (though it yields a small net increase).

In general, you want to keep your deep cloning to an absolute minimum, so that you don't have to call protoClone() but one time.

The approach taken here is the fastest that I am aware of while still permitting objects to be specified at runtime from a parameter file. It would be faster to use the "new" operator; but that would require hard-coding that we can't do. Although using java.lang.Object.clone() entails an extra layer that deals with stripping away the "protected" keyword and also wrapping the exception handling (which is a BIG hit, about three times as slow as using "new"), it's still MUCH faster than using java.lang.Class.newInstance(), and also much faster than rolling our own Clone() method.

Specified by:
protoClone in interface Prototype

protoCloneSimple

public final java.lang.Object protoCloneSimple()
Description copied from interface: Prototype
This should be implemented in a the top-level Prototype ONLY; in fact, it should probably be declared final. It should be implemented as follows:

public final Object protoCloneSimple()
{
try { return protoClone(); }
catch (CloneNotSupportedException e) 
{ throw new InternalError(); } // never happens
} 
Specified by:
protoCloneSimple in interface Prototype

setup

public void setup(EvolutionState state,
                  Parameter base)
Description copied from interface: Prototype
Sets up the object by reading it from the parameters stored in state, built off of the parameter base base. If an ancestor implements this method, be sure to call super.setup(state,base); before you do anything else.

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.

Specified by:
setup in interface Prototype

evaluate

public void evaluate(EvolutionState state,
                     int thread,
                     GPData input,
                     ADFStack stack,
                     GPIndividual individual,
                     Problem problem,
                     int argument)
Evaluates the argument number in the current context

prepareADF

public final void prepareADF(ADF a)
Increases arguments to accommodate space if necessary. Sets adf to a. You need to then fill out the arguments yourself.

prepareADM

public final void prepareADM(ADM a)
Sets adf to a