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Commons Math example source code file (

This example Commons Math source code file ( is included in the "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Commons Math tags/keywords

default_absolute_threshold, default_absolute_threshold, default_relative_threshold, default_relative_threshold, simplevectorialpointchecker, simplevectorialpointchecker, vectorialconvergencechecker, vectorialpointvaluepair, vectorialpointvaluepair

The Commons Math source code

 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * See the License for the specific language governing permissions and
 * limitations under the License.

package org.apache.commons.math.optimization;

import org.apache.commons.math.util.MathUtils;

 * Simple implementation of the {@link VectorialConvergenceChecker} interface using
 * only point coordinates.
 * <p>
 * Convergence is considered to have been reached if either the relative
 * difference between each point coordinate are smaller than a threshold
 * or if either the absolute difference between the point coordinates are
 * smaller than another threshold.
 * </p>
 * @version $Revision: 811685 $ $Date: 2009-09-05 13:36:48 -0400 (Sat, 05 Sep 2009) $
 * @since 2.0
public class SimpleVectorialPointChecker implements VectorialConvergenceChecker {

    /** Default relative threshold. */
    private static final double DEFAULT_RELATIVE_THRESHOLD = 100 * MathUtils.EPSILON;

    /** Default absolute threshold. */
    private static final double DEFAULT_ABSOLUTE_THRESHOLD = 100 * MathUtils.SAFE_MIN;

    /** Relative tolerance threshold. */
    private final double relativeThreshold;

    /** Absolute tolerance threshold. */
    private final double absoluteThreshold;

   /** Build an instance with default threshold.
    public SimpleVectorialPointChecker() {
        this.relativeThreshold = DEFAULT_RELATIVE_THRESHOLD;
        this.absoluteThreshold = DEFAULT_ABSOLUTE_THRESHOLD;

    /** Build an instance with a specified threshold.
     * <p>
     * In order to perform only relative checks, the absolute tolerance
     * must be set to a negative value. In order to perform only absolute
     * checks, the relative tolerance must be set to a negative value.
     * </p>
     * @param relativeThreshold relative tolerance threshold
     * @param absoluteThreshold absolute tolerance threshold
    public SimpleVectorialPointChecker(final double relativeThreshold,
                                       final double absoluteThreshold) {
        this.relativeThreshold = relativeThreshold;
        this.absoluteThreshold = absoluteThreshold;

    /** {@inheritDoc} */
    public boolean converged(final int iteration,
                             final VectorialPointValuePair previous,
                             final VectorialPointValuePair current) {
        final double[] p = previous.getPointRef();
        final double[] c = current.getPointRef();
        for (int i = 0; i < p.length; ++i) {
            final double pi         = p[i];
            final double ci         = c[i];
            final double difference = Math.abs(pi - ci);
            final double size       = Math.max(Math.abs(pi), Math.abs(ci));
            if ((difference > (size * relativeThreshold)) &&
                (difference > absoluteThreshold)) {
                return false;
        return true;


Other Commons Math examples (source code examples)

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