/*******************************************************************************
* 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.core.proposalKernels;
import static com.analog.lyric.dimple.environment.DimpleEnvironment.*;
import java.util.List;
import org.eclipse.jdt.annotation.Nullable;
import com.analog.lyric.dimple.model.domains.DiscreteDomain;
import com.analog.lyric.dimple.model.domains.Domain;
import com.analog.lyric.dimple.model.values.DiscreteValue;
import com.analog.lyric.dimple.model.values.Value;
import com.analog.lyric.options.IOptionHolder;
import com.analog.lyric.options.Option;
/**
* @since 0.05
*/
public class UniformDiscreteProposalKernel implements IProposalKernel
{
@Override
public Proposal next(Value currentValue, Domain variableDomain)
{
// Choose uniformly at random from among all values except the current value
DiscreteDomain domain = (DiscreteDomain)variableDomain;
int currentIndex = ((DiscreteValue)currentValue).getIndex();
int nextIndex = activeRandom().nextInt(domain.size() - 1);
if (nextIndex >= currentIndex) nextIndex++;
Value value = Value.create(domain);
value.setIndex(nextIndex);
return new Proposal(value);
}
@Override
public void setParameters(Object... parameters)
{
}
@Override
public @Nullable Object[] getParameters()
{
return null;
}
@Override
public void configureFromOptions(IOptionHolder optionHolder)
{
}
@Override
public @Nullable List<Option<?>> getOptionConfiguration(@Nullable List<Option<?>> list)
{
return list;
}
}