/*******************************************************************************
* 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;
import com.analog.lyric.dimple.factorfunctions.core.FactorFunction;
import com.analog.lyric.dimple.model.values.Value;
/**
* Deterministic logical AND. This is a deterministic directed factor.
*
* The variables are ordered as follows in the argument list:
*
* 1) Output (Logical AND of inputs)
* 2...) An arbitrary number of inputs (inputs may be boolean, double 0.0/1.0 or integer 0/1)
*
*/
public class And extends FactorFunction
{
@Override
public final double evalEnergy(Value[] arguments)
{
final boolean outValue = arguments[0].getBoolean();
boolean andValue = true;
for(int i = 1; i < arguments.length; ++i)
andValue &= arguments[i].getBoolean();
return (andValue == outValue) ? 0 : Double.POSITIVE_INFINITY;
}
@Override
public final boolean isDirected() {return true;}
@Override
public final int[] getDirectedToIndices() {return new int[]{0};}
@Override
public final boolean isDeterministicDirected() {return true;}
@Override
public final void evalDeterministic(Value[] arguments)
{
boolean andValue = true;
for (int i = 1; i < arguments.length; ++i)
andValue &= arguments[i].getBoolean();
// Replace the output value
arguments[0].setBoolean(andValue);
}
}