/*******************************************************************************
* Copyright 2012 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.minsum;
import java.util.Arrays;
import org.eclipse.jdt.annotation.Nullable;
import com.analog.lyric.collect.ArrayUtil;
import com.analog.lyric.collect.Selection;
import com.analog.lyric.dimple.environment.DimpleEnvironment;
import com.analog.lyric.dimple.exceptions.DimpleException;
import com.analog.lyric.dimple.factorfunctions.core.FactorFunction;
import com.analog.lyric.dimple.factorfunctions.core.FactorTableRepresentation;
import com.analog.lyric.dimple.factorfunctions.core.IFactorTable;
import com.analog.lyric.dimple.model.factors.Factor;
import com.analog.lyric.dimple.model.variables.Variable;
import com.analog.lyric.dimple.options.BPOptions;
import com.analog.lyric.dimple.solvers.core.STableFactorDoubleArray;
import com.analog.lyric.dimple.solvers.core.kbest.IKBestFactor;
import com.analog.lyric.dimple.solvers.core.kbest.KBestFactorEngine;
import com.analog.lyric.dimple.solvers.core.kbest.KBestFactorTableEngine;
import com.analog.lyric.dimple.solvers.core.parameterizedMessages.DiscreteEnergyMessage;
import com.analog.lyric.dimple.solvers.interfaces.ISolverFactorGraph;
import com.analog.lyric.dimple.solvers.optimizedupdate.FactorTableUpdateSettings;
import com.analog.lyric.dimple.solvers.optimizedupdate.FactorUpdatePlan;
import com.analog.lyric.dimple.solvers.optimizedupdate.ISTableFactorSupportingOptimizedUpdate;
import com.analog.lyric.dimple.solvers.optimizedupdate.UpdateApproach;
import com.analog.lyric.util.misc.Internal;
/**
* Solver table factor under Min-Sum solver.
*
* @since 0.07
*/
public class MinSumTableFactor extends STableFactorDoubleArray
implements IKBestFactor, ISTableFactorSupportingOptimizedUpdate
{
/*
* We cache all of the double arrays we use during the update. This saves
* time when performing the update.
*/
protected double[][] _inputMessages = ArrayUtil.EMPTY_DOUBLE_ARRAY_ARRAY;
protected double[][] _outputMessages = ArrayUtil.EMPTY_DOUBLE_ARRAY_ARRAY;
protected double[] _dampingParams = ArrayUtil.EMPTY_DOUBLE_ARRAY;
protected @Nullable TableFactorEngine _tableFactorEngine;
protected KBestFactorEngine _kbestFactorEngine;
protected int _k;
protected boolean _kIsSmallerThanDomain;
protected boolean _dampingInUse = false;
/*--------------
* Construction
*/
public MinSumTableFactor(Factor factor, ISolverFactorGraph parent)
{
super(factor, parent);
if (factor.getFactorFunction().factorTableExists(getFactor()))
_kbestFactorEngine = new KBestFactorTableEngine(this);
else
_kbestFactorEngine = new KBestFactorEngine(this);
}
@Override
public void initialize()
{
super.initialize();
configureDampingFromOptions();
updateK(getOptionOrDefault(BPOptions.maxMessageSize));
final int nSiblings = getSiblingCount();
if (nSiblings != _inputMessages.length)
{
_inputMessages = new double[nSiblings][];
_outputMessages = new double[nSiblings][];
}
for (int i = 0; i < nSiblings; ++i)
{
final MinSumDiscreteEdge edge = getSiblingEdgeState(i);
_inputMessages[i] = edge.varToFactorMsg.representation();
_outputMessages[i] = edge.factorToVarMsg.representation();
}
}
void setupTableFactorEngine()
{
FactorUpdatePlan updatePlan = null;
final FactorTableUpdateSettings factorTableUpdateSettings = getFactorTableUpdateSettings();
if (factorTableUpdateSettings != null)
{
updatePlan = factorTableUpdateSettings.getOptimizedUpdatePlan();
}
if (updatePlan != null)
{
_tableFactorEngine = new TableFactorEngineOptimized(this, updatePlan);
}
else
{
_tableFactorEngine = new TableFactorEngine(this);
}
}
@Internal
@Nullable FactorTableUpdateSettings getFactorTableUpdateSettings()
{
ISolverFactorGraph rootGraph = getRootSolverGraph();
if (rootGraph instanceof MinSumSolverGraph)
{
final MinSumSolverGraph sfg = (MinSumSolverGraph) rootGraph;
return sfg.getFactorTableUpdateSettings(getFactor());
}
return null;
}
/*---------------------
* ISolverNode methods
*/
private TableFactorEngine getTableFactorEngine()
{
final TableFactorEngine tableFactorEngine = _tableFactorEngine;
if (tableFactorEngine != null)
{
return tableFactorEngine;
}
else
{
throw new DimpleException("The solver was not initialized. Use solve() or call initialize() before iterate().");
}
}
@Override
protected void doUpdate()
{
if (_kIsSmallerThanDomain)
_kbestFactorEngine.update();
else
getTableFactorEngine().update();
}
@Override
public void doUpdateEdge(int outPortNum)
{
if (_kIsSmallerThanDomain)
_kbestFactorEngine.updateEdge(outPortNum);
else
getTableFactorEngine().updateEdge(outPortNum);
}
public int getK()
{
return _k;
}
public void setK(int k)
{
setOption(BPOptions.maxMessageSize, k);
updateK(k);
}
private void updateK(int k)
{
if (k != _k)
{
_k = k;
_kbestFactorEngine.setK(k);
_kIsSmallerThanDomain = false;
for (Variable var : _model.getSiblings())
{
if (k < var.asDiscreteVariable().getDomain().size())
{
_kIsSmallerThanDomain = true;
break;
}
}
}
}
/*-----------------------
* ISolverFactor methods
*/
/*--------------------------
* STableFactorBase methods
*/
@Override
protected void setTableRepresentation(IFactorTable table)
{
table.setRepresentation(FactorTableRepresentation.SPARSE_ENERGY_WITH_INDICES);
}
/*----------------------
* IKBestFactor methods
*/
@Override
public FactorFunction getFactorFunction()
{
return getFactor().getFactorFunction();
}
@Override
public double initAccumulator()
{
return 0;
}
@Override
public double accumulate(double oldVal, double newVal)
{
return oldVal + newVal;
}
@Override
public double combine(double oldVal, double newVal)
{
if (oldVal < newVal)
return oldVal;
else
return newVal;
}
@Override
public void normalize(double[] outputMsg)
{
double minVal = Double.POSITIVE_INFINITY;
for (int i = 0; i < outputMsg.length; i++)
if (outputMsg[i] < minVal)
minVal = outputMsg[i];
for (int i = 0; i < outputMsg.length; i++)
outputMsg[i] -= minVal;
}
@Override
public double evalFactorFunction(Object[] inputs)
{
return _model.evalEnergy(inputs);
}
@Override
public void initMsg(double[] msg)
{
Arrays.fill(msg, Double.POSITIVE_INFINITY);
}
@Override
public double getFactorTableValue(int index)
{
return getFactorTable().getEnergiesSparseUnsafe()[index];
}
@Override
public int[] findKBestForMsg(double[] msg, int k)
{
return Selection.findFirstKIndices(msg, k);
}
@Override
public double[][] getInPortMsgs()
{
return _inputMessages;
}
@Override
public double[] getInPortMsg(int edgeNumber)
{
return _inputMessages[edgeNumber];
}
@Override
public double[][] getOutPortMsgs()
{
return _outputMessages;
}
@Override
public double[] getOutPortMsg(int edgeNumber)
{
return _outputMessages[edgeNumber];
}
/*---------------
* SNode methods
*/
@Override
protected DiscreteEnergyMessage cloneMessage(int edge)
{
return getSiblingEdgeState(edge).factorToVarMsg.clone();
}
@Override
protected boolean supportsMessageEvents()
{
return true;
}
/*-------------
* New methods
*/
/**
* @deprecated Use {@link BPOptions#damping} or {@link BPOptions#nodeSpecificDamping} options instead.
*/
@Deprecated
public void setDamping(int index, double val)
{
double[] params = BPOptions.nodeSpecificDamping.getOrDefault(this).toPrimitiveArray();
if (params.length == 0 && val != 0.0)
{
params = new double[getSiblingCount()];
}
if (params.length != 0)
{
params[index] = val;
}
BPOptions.nodeSpecificDamping.set(this, params);
configureDampingFromOptions();
}
@Override
public double getDamping(int index)
{
return _dampingParams.length > 0 ? _dampingParams[index] : 0.0;
}
/**
* Returns the effective update approach for the factor. If the update approach is set to
* automatic, this value is not valid until the graph is initialized. Note that a factor
* with only one edge always employs the normal update approach.
*
* @since 0.07
*/
public UpdateApproach getEffectiveUpdateApproach()
{
final FactorTableUpdateSettings factorTableUpdateSettings = getFactorTableUpdateSettings();
if (factorTableUpdateSettings != null && factorTableUpdateSettings.getOptimizedUpdatePlan() != null)
{
return UpdateApproach.OPTIMIZED;
}
else
{
return UpdateApproach.NORMAL;
}
}
@Internal
public @Nullable UpdateApproach getAutomaticUpdateApproach()
{
FactorTableUpdateSettings updateSettings = getFactorTableUpdateSettings();
if (updateSettings != null)
{
return updateSettings.getAutomaticUpdateApproach();
}
return null;
}
@Override
public boolean isDampingInUse()
{
return _dampingInUse;
}
/*------------------
* Internal methods
*/
protected void configureDampingFromOptions()
{
final int size = getSiblingCount();
_dampingParams =
getReplicatedNonZeroListFromOptions(BPOptions.nodeSpecificDamping, BPOptions.damping,
size, _dampingParams);
if (_dampingParams.length > 0 && _dampingParams.length != size)
{
DimpleEnvironment.logWarning("%s has wrong number of parameters for %s\n",
BPOptions.nodeSpecificDamping, this);
_dampingParams = ArrayUtil.EMPTY_DOUBLE_ARRAY;
}
_dampingInUse = _dampingParams.length > 0;
}
@Override
@SuppressWarnings("null")
public MinSumDiscreteEdge getSiblingEdgeState(int siblingIndex)
{
return (MinSumDiscreteEdge)getSiblingEdgeState_(siblingIndex);
}
}