/***********************************************************************************************************************
*
* Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
*
* 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 eu.stratosphere.api.common.aggregators;
import eu.stratosphere.types.DoubleValue;
/**
* A {@link ConvergenceCriterion} over an {@link Aggregator} that defines convergence as reached once the aggregator
* holds the value zero. The aggregated data type is a {@link DoubleValue}.
*/
public class DoubleZeroConvergence implements ConvergenceCriterion<DoubleValue> {
/**
* Returns true, if the aggregator value is zero, false otherwise.
*
* @param iteration The number of the iteration superstep. Ignored in this case.
* @param value The aggregator value, which is compared to zero.
* @return True, if the aggregator value is zero, false otherwise.
*/
@Override
public boolean isConverged(int iteration, DoubleValue value) {
return value.getValue() == 0;
}
}