/*******************************************************************************
* Copyright 2013 Analog Devices, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
********************************************************************************/
package com.analog.lyric.dimple.solvers.gibbs.customFactors;
import static java.util.Objects.*;
import java.util.HashSet;
import java.util.Set;
import org.eclipse.jdt.annotation.Nullable;
import com.analog.lyric.dimple.factorfunctions.Beta;
import com.analog.lyric.dimple.factorfunctions.core.FactorFunction;
import com.analog.lyric.dimple.model.core.EdgeState;
import com.analog.lyric.dimple.model.factors.Factor;
import com.analog.lyric.dimple.solvers.core.parameterizedMessages.BetaParameters;
import com.analog.lyric.dimple.solvers.gibbs.GibbsBetaEdge;
import com.analog.lyric.dimple.solvers.gibbs.GibbsReal;
import com.analog.lyric.dimple.solvers.gibbs.GibbsRealFactor;
import com.analog.lyric.dimple.solvers.gibbs.GibbsSolverEdge;
import com.analog.lyric.dimple.solvers.gibbs.GibbsSolverGraph;
import com.analog.lyric.dimple.solvers.gibbs.samplers.conjugate.BetaSampler;
import com.analog.lyric.dimple.solvers.gibbs.samplers.conjugate.IRealConjugateSamplerFactory;
public class CustomBeta extends GibbsRealFactor implements IRealConjugateFactor
{
private @Nullable GibbsReal _alphaVariable;
private @Nullable GibbsReal _betaVariable;
private boolean _hasConstantAlpha;
private boolean _hasConstantBeta;
private boolean _hasFactorFunctionConstructorConstants;
private int _numParameterEdges;
private int _alphaParameterPort = -1;
private int _betaParameterPort = -1;
private double _constantAlphaMinusOneValue;
private double _constantBetaMinusOneValue;
private static final int ALPHA_PARAMETER_INDEX = 0;
private static final int BETA_PARAMETER_INDEX = 1;
private static final int NO_PORT = -1;
public CustomBeta(Factor factor, GibbsSolverGraph parent)
{
super(factor, parent);
}
@Override
public @Nullable GibbsSolverEdge<?> createEdge(EdgeState edge)
{
if (edge.getFactorToVariableEdgeNumber() >= _numParameterEdges)
{
return new GibbsBetaEdge();
}
return super.createEdge(edge);
}
@SuppressWarnings("null")
@Override
public void updateEdgeMessage(EdgeState modelEdge, GibbsSolverEdge<?> solverEdge)
{
final int portNum = modelEdge.getFactorToVariableEdgeNumber();
if (portNum >= _numParameterEdges)
{
// Port is directed output
BetaParameters outputMsg = (BetaParameters)solverEdge.factorToVarMsg;
outputMsg.setAlphaMinusOne(_hasConstantAlpha ? _constantAlphaMinusOneValue : _alphaVariable.getCurrentSample() - 1);
outputMsg.setBetaMinusOne(_hasConstantBeta ? _constantBetaMinusOneValue : _betaVariable.getCurrentSample() - 1);
}
else
super.updateEdgeMessage(modelEdge, solverEdge);
}
@Override
public Set<IRealConjugateSamplerFactory> getAvailableRealConjugateSamplers(int portNumber)
{
Set<IRealConjugateSamplerFactory> availableSamplers = new HashSet<IRealConjugateSamplerFactory>();
if (isPortOutputVariable(portNumber))
availableSamplers.add(BetaSampler.factory); // Output variables have Beta distribution
return availableSamplers;
}
public boolean isPortOutputVariable(int portNumber)
{
determineConstantsAndEdges(); // Call this here since initialize may not have been called yet
return (portNumber >= _numParameterEdges);
}
@Override
public void initialize()
{
super.initialize();
// Determine what parameters are constants or edges, and save the state
determineConstantsAndEdges();
}
private void determineConstantsAndEdges()
{
// Get the factor function and related state
final Factor factor = _model;
FactorFunction factorFunction = factor.getFactorFunction();
Beta specificFactorFunction = (Beta)factorFunction;
_hasFactorFunctionConstructorConstants = specificFactorFunction.hasConstantParameters();
final int prevNumParameterEdges = _numParameterEdges;
// Pre-determine whether or not the parameters are constant; if so save the value; if not save reference to the variable
_hasConstantAlpha = false;
_hasConstantBeta = false;
_alphaParameterPort = NO_PORT;
_betaParameterPort = NO_PORT;
_alphaVariable = null;
_betaVariable = null;
_constantAlphaMinusOneValue = 0;
_constantBetaMinusOneValue = 0;
_numParameterEdges = 0;
if (_hasFactorFunctionConstructorConstants)
{
// The factor function has fixed parameters provided in the factor-function constructor
_hasConstantAlpha = true;
_hasConstantBeta = true;
_constantAlphaMinusOneValue = specificFactorFunction.getAlphaMinusOne();
_constantBetaMinusOneValue = specificFactorFunction.getBetaMinusOne();
}
else // Variable or constant parameters
{
_hasConstantAlpha = factor.hasConstantAtIndex(ALPHA_PARAMETER_INDEX);
if (_hasConstantAlpha) // Constant mean
_constantAlphaMinusOneValue =
requireNonNull(factor.getConstantValueByIndex(ALPHA_PARAMETER_INDEX)).getDouble() - 1;
else // Variable mean
{
_alphaParameterPort = factor.argIndexToSiblingNumber(ALPHA_PARAMETER_INDEX);
_alphaVariable = (GibbsReal)getSibling(_alphaParameterPort);
_numParameterEdges++;
}
_hasConstantBeta = factor.hasConstantAtIndex(BETA_PARAMETER_INDEX);
if (_hasConstantBeta) // Constant precision
_constantBetaMinusOneValue =
requireNonNull(factor.getConstantValueByIndex(BETA_PARAMETER_INDEX)).getDouble() - 1;
else // Variable precision
{
_betaParameterPort = factor.argIndexToSiblingNumber(BETA_PARAMETER_INDEX);
_betaVariable = (GibbsReal)getSibling(_betaParameterPort);
_numParameterEdges++;
}
}
if (_numParameterEdges != prevNumParameterEdges)
{
removeSiblingEdgeState();
}
}
}