Class BernoulliUmdaModel

java.lang.Object

com.knezevic.edaf.v3.models.discrete.BernoulliUmdaModel

All Implemented Interfaces:

Model<BitString>

public final class BernoulliUmdaModel
extends Object
implements Model<BitString>

Univariate Marginal Distribution Algorithm (UMDA) model for bitstrings.

The model assumes conditional independence between loci and estimates a Bernoulli parameter per bit from selected elites:

   p_i = s + (1 - 2s) * mean(x_i)
 

where s is smoothing and mean(x_i) is empirical elite frequency of bit i being one.

Smoothing keeps probabilities away from 0 and 1, preventing premature fixation and enabling deterministic checkpoint/restart behavior.

Constructor Summary

Constructors

Constructor	Description
BernoulliUmdaModel(double smoothing)

Method Summary

Modifier and Type	Method	Description
ModelDiagnostics	diagnostics()	Exposes diagnostics (entropy, covariance condition number, etc.).
void	fit(List<Individual<BitString>> selected, Representation<BitString> representation, RngStream rng)	Fits model parameters from selected individuals.
String	name()	Model identifier used in configuration and listing commands.
double[]	probabilities()	Returns a defensive copy of current Bernoulli parameters.
void	restore(double[] probabilities)	Restores model state from checkpoint payload.
List<BitString>	sample(int count, Representation<BitString> representation, Problem<BitString> problem, ConstraintHandling<BitString> constraintHandling, RngStream rng)	Samples new genotypes from model.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.knezevic.edaf.v3.core.api.Model

update

Constructor Details

BernoulliUmdaModel

public BernoulliUmdaModel(double smoothing)

Parameters:

smoothing - probability-floor coefficient in [0, 0.49].

Method Details

name

public String name()

Description copied from interface: Model

Model identifier used in configuration and listing commands.

Specified by:

name in interface Model<BitString>

fit

public void fit(List<Individual<BitString>> selected,
 Representation<BitString> representation,
 RngStream rng)

Description copied from interface: Model

Fits model parameters from selected individuals.

Specified by:

fit in interface Model<BitString>

sample

public List<BitString> sample(int count,
 Representation<BitString> representation,
 Problem<BitString> problem,
 ConstraintHandling<BitString> constraintHandling,
 RngStream rng)

Description copied from interface: Model

Samples new genotypes from model.

Specified by:

sample in interface Model<BitString>

diagnostics

public ModelDiagnostics diagnostics()

Description copied from interface: Model

Exposes diagnostics (entropy, covariance condition number, etc.).

Specified by:

diagnostics in interface Model<BitString>

probabilities

public double[] probabilities()

Returns a defensive copy of current Bernoulli parameters.

restore

public void restore(double[] probabilities)

Restores model state from checkpoint payload.