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.math4.ode.sampling;
019
020
021/** {@link StepNormalizer Step normalizer} modes. Determines how the step size
022 * is interpreted.
023 * @see FieldStepNormalizer
024 * @see StepNormalizer
025 * @see StepNormalizerBounds
026 * @since 3.0
027 */
028public enum StepNormalizerMode {
029    /**
030     * Steps are fixed increments of the start value. In other words, they
031     * are relative to the start value.
032     *
033     * <p>If the integration start time is t0, then the points handled by
034     * the underlying fixed step size step handler are t0 (depending on
035     * the {@link StepNormalizerBounds bounds settings}), t0+h, t0+2h, ...</p>
036     *
037     * <p>If the integration range is an integer multiple of the step size
038     * (h), then the last point handled will be the end point of the
039     * integration (tend). If not, the last point may be the end point
040     * tend, or it may be a point belonging to the interval [tend - h ;
041     * tend], depending on the {@link StepNormalizerBounds bounds settings}.
042     * </p>
043     *
044     * @see StepNormalizer
045     * @see StepNormalizerBounds
046     */
047    INCREMENT,
048
049    /** Steps are multiples of a fixed value. In other words, they are
050     * relative to the first multiple of the step size that is encountered
051     * after the start value.
052     *
053     * <p>If the integration start time is t0, and the first multiple of
054     * the fixed step size that is encountered is t1, then the points
055     * handled by the underlying fixed step size step handler are t0
056     * (depending on the {@link StepNormalizerBounds bounds settings}), t1,
057     * t1+h, t1+2h, ...</p>
058     *
059     * <p>If the end point of the integration range (tend) is an integer
060     * multiple of the step size (h) added to t1, then the last point
061     * handled will be the end point of the integration (tend). If not,
062     * the last point may be the end point tend, or it may be a point
063     * belonging to the interval [tend - h ; tend], depending on the
064     * {@link StepNormalizerBounds bounds settings}.</p>
065     *
066     * @see StepNormalizer
067     * @see StepNormalizerBounds
068     */
069    MULTIPLES;
070}