001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.apache.commons.math3.optimization;
019
020import org.apache.commons.math3.util.Precision;
021
022/**
023 * Base class for all convergence checker implementations.
024 *
025 * @param <PAIR> Type of (point, value) pair.
026 *
027 * @version $Id: AbstractConvergenceChecker.java 1422230 2012-12-15 12:11:13Z erans $
028 * @deprecated As of 3.1 (to be removed in 4.0).
029 * @since 3.0
030 */
031@Deprecated
032public abstract class AbstractConvergenceChecker<PAIR>
033    implements ConvergenceChecker<PAIR> {
034    /**
035     * Default relative threshold.
036     * @deprecated in 3.1 (to be removed in 4.0) because this value is too small
037     * to be useful as a default (cf. MATH-798).
038     */
039    @Deprecated
040    private static final double DEFAULT_RELATIVE_THRESHOLD = 100 * Precision.EPSILON;
041    /**
042     * Default absolute threshold.
043     * @deprecated in 3.1 (to be removed in 4.0) because this value is too small
044     * to be useful as a default (cf. MATH-798).
045     */
046    @Deprecated
047    private static final double DEFAULT_ABSOLUTE_THRESHOLD = 100 * Precision.SAFE_MIN;
048    /**
049     * Relative tolerance threshold.
050     */
051    private final double relativeThreshold;
052    /**
053     * Absolute tolerance threshold.
054     */
055    private final double absoluteThreshold;
056
057    /**
058     * Build an instance with default thresholds.
059     * @deprecated in 3.1 (to be removed in 4.0). Convergence thresholds are
060     * problem-dependent. As this class is intended for users who want to set
061     * their own convergence criterion instead of relying on an algorithm's
062     * default procedure, they should also set the thresholds appropriately
063     * (cf. MATH-798).
064     */
065    @Deprecated
066    public AbstractConvergenceChecker() {
067        this.relativeThreshold = DEFAULT_RELATIVE_THRESHOLD;
068        this.absoluteThreshold = DEFAULT_ABSOLUTE_THRESHOLD;
069    }
070
071    /**
072     * Build an instance with a specified thresholds.
073     *
074     * @param relativeThreshold relative tolerance threshold
075     * @param absoluteThreshold absolute tolerance threshold
076     */
077    public AbstractConvergenceChecker(final double relativeThreshold,
078                                      final double absoluteThreshold) {
079        this.relativeThreshold = relativeThreshold;
080        this.absoluteThreshold = absoluteThreshold;
081    }
082
083    /**
084     * @return the relative threshold.
085     */
086    public double getRelativeThreshold() {
087        return relativeThreshold;
088    }
089
090    /**
091     * @return the absolute threshold.
092     */
093    public double getAbsoluteThreshold() {
094        return absoluteThreshold;
095    }
096
097    /**
098     * {@inheritDoc}
099     */
100    public abstract boolean converged(int iteration,
101                                      PAIR previous,
102                                      PAIR current);
103}