    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
    018    package org.apache.commons.math3.optimization;
    019
    020    import 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
    032    public 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    }