/*******************************************************************************
* Copyright 2014 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.junctiontree;
import com.analog.lyric.dimple.model.transform.JunctionTreeTransform;
import com.analog.lyric.dimple.model.transform.VariableEliminator;
import com.analog.lyric.dimple.model.transform.VariableEliminator.VariableCost;
import com.analog.lyric.dimple.model.transform.VariableEliminatorCostListOptionKey;
import com.analog.lyric.dimple.options.BPOptions;
import com.analog.lyric.options.BooleanOptionKey;
import com.analog.lyric.options.IntegerOptionKey;
/**
* Options for the junction tree solvers.
* <p>
* Options are configured during {@linkplain JunctionTreeSolverGraphBase#initialize initialize}
* unless otherwise noted.
* <p>
* @since 0.07
* @author Christopher Barber
*/
public class JunctionTreeOptions extends BPOptions
{
/**
* If true, then the transformation will condition out any variables that have a fixed value.
* This will produce a more efficient graph but will prevent it from being reused if the fixed
* value changes.
* <p>
* False by default.
* <p>
* @since 0.07
*/
public static final BooleanOptionKey useConditioning =
new BooleanOptionKey(JunctionTreeOptions.class, "useConditioning", false);
/**
* Specifies the maximum number of times to attempt to determine an optimal junction tree
* transformation.
* <p>
* Specifies the number of iterations of the {@link VariableEliminator} algorithm when
* attempting to determine the variable elimination ordering that determines the junction tree
* transformation. Each iteration will pick a cost function from specified
* {@link #variableEliminatorCostFunctions} at random and will randomize the order of
* variables that have equivalent costs. A higher number of iterations may produce a better
* ordering.
* <p>
* Must be a positive value. Default value is specified by
* {@link JunctionTreeTransform#DEFAULT_MAX_TRANSFORMATION_ATTEMPTS}.
* <p>
* @since 0.07
*/
public static final IntegerOptionKey maxTransformationAttempts =
new IntegerOptionKey(JunctionTreeOptions.class, "maxTransformationAttempts",
JunctionTreeTransform.DEFAULT_MAX_TRANSFORMATION_ATTEMPTS, 1, Integer.MAX_VALUE);
/**
* Specifies which cost functions the variable elimination algorithm should use when
* attempting to optimize the junction tree transformation. An empty list indicates that
* all should be tried.
* <p>
* The default is the empty list.
* <p>
* @see VariableCost
* @since 0.07
*/
public static final VariableEliminatorCostListOptionKey variableEliminatorCostFunctions =
new VariableEliminatorCostListOptionKey(JunctionTreeOptions.class, "variableEliminatorCostFunctions");
}