/*******************************************************************************
* 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.factorfunctions.core;
import static java.util.Objects.*;
import java.util.List;
import java.util.Objects;
import org.eclipse.jdt.annotation.Nullable;
import com.analog.lyric.collect.ArrayUtil;
import com.analog.lyric.dimple.model.domains.DiscreteDomain;
import com.analog.lyric.dimple.model.domains.JointDomainIndexer;
import com.analog.lyric.dimple.model.factors.Factor;
import com.analog.lyric.dimple.model.values.Value;
import com.analog.lyric.dimple.model.variables.Discrete;
/**
* A factor function based on a factor table.
* <p>
*/
public class TableFactorFunction extends FactorFunction
{
/*-------
* State
*/
private final IFactorTable _factorTable;
private final int[] _argNumberToTableDimension;
private final @Nullable Value[] _constants;
/*
* Construction
*/
private TableFactorFunction(IFactorTable factorTable, int[] argNumberToTableDimension, List<Value> constants)
{
super();
_factorTable = factorTable;
_argNumberToTableDimension = argNumberToTableDimension;
_constants = constants.toArray(new Value[constants.size()]);
}
public TableFactorFunction(String name, IFactorTable factorTable)
{
super(name);
_factorTable = factorTable;
_argNumberToTableDimension = ArrayUtil.EMPTY_INT_ARRAY;
_constants = null;
}
public static TableFactorFunction forFactor(Factor factor, IFactorTable factorTable)
{
return new TableFactorFunction(factorTable, factor.getArgIndexToToSiblingNumberMapping(),
factor.getConstantValues());
}
public TableFactorFunction(String name, int [][] indices, double [] probs, DiscreteDomain ... domains)
{
this(name,FactorTable.create(indices, probs, domains));
}
public TableFactorFunction(String name, int [][] indices, double [] probs, Discrete... discretes)
{
this(name,FactorTable.create(indices, probs, discretes));
}
/*------------------------
* FactorFunction methods
*/
@Override
public boolean convertFactorTable(@Nullable JointDomainIndexer oldDomains, @Nullable JointDomainIndexer newDomains)
{
boolean converted = false;
if (oldDomains != null && newDomains != null)
{
_factorTable.setConditional(Objects.requireNonNull(newDomains.getOutputSet()));
converted = true;
}
return converted;
}
@Override
public boolean factorTableExists(@Nullable JointDomainIndexer domains)
{
if (domains ==null || domains.size() != _factorTable.getDimensions())
{
return false;
}
return true;
}
@Override
public double evalEnergy(Value[] input)
{
final int[] argToTableDimension = _argNumberToTableDimension;
if (argToTableDimension.length > 0)
{
final int nDims = _factorTable.getDimensions();
Value[] tmp = new Value[nDims];
for (int i = argToTableDimension.length; --i>=0;)
{
final Value value = input[i];
int j = argToTableDimension[i];
if (j < nDims)
{
tmp[j] = value;
}
else
{
final Value constant = requireNonNull(_constants)[j - nDims];
if (!constant.valueEquals(value))
{
return Double.POSITIVE_INFINITY;
}
}
}
input = tmp;
}
return _factorTable.getEnergyForValues(input);
}
@Override
public JointDomainIndexer getDomains()
{
return _factorTable.getDomainIndexer();
}
public IFactorTable getFactorTable()
{
return _factorTable;
}
@Override
public IFactorTable getFactorTable(@Nullable JointDomainIndexer domains)
{
if (domains == null)
{
// Invoke superclass version to throw error
return super.getFactorTable((JointDomainIndexer)null);
}
//first step, convert domains to DiscreteDOmains
//make sure domain lists match
if (domains.size() != _factorTable.getDimensions())
throw new RuntimeException("domain lists don't match sizes. argument size: " + domains.size() +
" factorTable's domain size: " + _factorTable.getDimensions());
return _factorTable;
}
@Override
public @Nullable IFactorTable getFactorTableIfExists(@Nullable JointDomainIndexer domains)
{
return factorTableExists(domains) ? _factorTable : null;
}
// For directed factors...
@Override
public boolean isDirected()
{
return _factorTable.isDirected();
}
@Override
protected @Nullable int[] getDirectedToIndices()
{
// FIXME Constant - convert to arg indices
return _factorTable.getDomainIndexer().getOutputDomainIndices();
}
// For deterministic directed factors...
// This means that for any given input, only one of its outputs has non-zero value (equivalently, finite energy)
@Override
public boolean isDeterministicDirected() {return _factorTable.isDeterministicDirected();}
// For deterministic directed factors, evaluate the deterministic function output(s) given only the inputs
// The arguments are in the same order as eval and evalEnergy, but in this case the output values should be overridden by new values
@Override
public void evalDeterministic(Value[] arguments)
{
final int[] argToTableDimension = _argNumberToTableDimension;
if (argToTableDimension.length > 0)
{
final int nDims = _factorTable.getDimensions();
final Value[] tmp = new Value[nDims];
for (int i = argToTableDimension.length; --i>=0;)
{
final int j = argToTableDimension[i];
if (j < nDims)
{
tmp[j] = arguments[i];
}
}
arguments = tmp;
}
_factorTable.evalDeterministic(arguments);
}
}