/***********************************************************************************************************************
* 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.test.recordJobs.graph.pageRankUtil;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import eu.stratosphere.api.common.aggregators.ConvergenceCriterion;
public class DiffL1NormConvergenceCriterion implements ConvergenceCriterion<PageRankStats> {
private static final double EPSILON = 0.00005;
private static final Log log = LogFactory.getLog(DiffL1NormConvergenceCriterion.class);
@Override
public boolean isConverged(int iteration, PageRankStats pageRankStats) {
double diff = pageRankStats.diff();
if (log.isInfoEnabled()) {
log.info("Stats in iteration [" + iteration + "]: " + pageRankStats);
log.info("L1 norm of the vector difference is [" + diff + "] in iteration [" + iteration + "]");
}
return diff < EPSILON;
}
}