FieldTimeSpanMap.java

  1. /* Copyright 2002-2018 CS Systèmes d'Information
  2.  * Licensed to CS Systèmes d'Information (CS) under one or more
  3.  * contributor license agreements.  See the NOTICE file distributed with
  4.  * this work for additional information regarding copyright ownership.
  5.  * CS licenses this file to You under the Apache License, Version 2.0
  6.  * (the "License"); you may not use this file except in compliance with
  7.  * the License.  You may obtain a copy of the License at
  8.  *
  9.  *   http://www.apache.org/licenses/LICENSE-2.0
  10.  *
  11.  * Unless required by applicable law or agreed to in writing, software
  12.  * distributed under the License is distributed on an "AS IS" BASIS,
  13.  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14.  * See the License for the specific language governing permissions and
  15.  * limitations under the License.
  16.  */
  17. package org.orekit.utils;

  19. import java.util.Collections;
  20. import java.util.NavigableSet;
  21. import java.util.SortedSet;
  22. import java.util.TreeSet;

  24. import org.orekit.time.FieldAbsoluteDate;
  25. import org.orekit.time.TimeStamped;
  26. import org.hipparchus.Field;
  27. import org.hipparchus.RealFieldElement;
  28. import org.orekit.time.AbsoluteDate;
  29. import org.orekit.time.ChronologicalComparator;

  31. /** Container for objects that apply to spans of time.

  33.  * @param <T> Type of the data.

  35.  * @author Luc Maisonobe
  36.  * @since 7.1
  37.  */
  38. public class FieldTimeSpanMap<T, D extends RealFieldElement<D>> {

  40.     /** Container for the data. */
  41.     private final NavigableSet<Transition<T, D>> data;

  43.     /**Field.*/
  44.     private final Field<D> field;

  46.     /** Create a map containing a single object, initially valid throughout the timeline.
  47.      * <p>
  48.      * The real validity of this first entry will be truncated as other
  49.      * entries are either {@link #addValidBefore(Object, FieldAbsoluteDate)
  50.      * added before} it or {@link #addValidAfter(Object, FieldAbsoluteDate)
  51.      * added after} it.
  52.      * </p>
  53.      * @param entry entry (initially valid throughout the timeline)
  54.      * @param field_n field used by default.
  55.      */
  56.     public FieldTimeSpanMap(final T entry, final Field<D> field_n) {
  57.         data = new TreeSet<Transition<T, D>>(new ChronologicalComparator());
  58.         field = field_n;
  59.         data.add(new Transition<>(new FieldAbsoluteDate<>(field), entry, entry));
  60.     }

  62.     /** Add an entry valid before a limit date.
  63.      * <p>
  64.      * As an entry is valid, it truncates the validity of the neighboring
  65.      * entries already present in the map.
  66.      * </p>
  67.      * <p>
  68.      * The transition dates should be entered only once, either
  69.      * by a call to this method or by a call to {@link #addValidAfter(Object,
  70.      * FieldAbsoluteDate)}. Repeating a transition date will lead to unexpected
  71.      * result and is not supported.
  72.      * </p>
  73.      * @param entry entry to add
  74.      * @param latestValidityDate date before which the entry is valid
  75.      * (sould be different from <em>all</em> dates already used for transitions)
  76.      */
  77.     public void addValidBefore(final T entry, final FieldAbsoluteDate<D> latestValidityDate) {

  79.         if (data.size() == 1) {
  80.             final Transition<T, D> single = data.first();
  81.             if (single.getBefore() == single.getAfter()) {
  82.                 // the single entry was a dummy one, without a real transition
  83.                 // we replace it entirely
  84.                 data.clear();
  85.                 data.add(new Transition<T, D>(latestValidityDate, entry, single.getAfter()));
  86.                 return;
  87.             }
  88.         }

  90.         final Transition<T, D> previous =
  91.                 data.floor(new Transition<T, D>(latestValidityDate, entry, null));
  92.         if (previous == null) {
  93.             // the new transition will be the first one
  94.             data.add(new Transition<T, D>(latestValidityDate, entry, data.first().getBefore()));
  95.         } else {
  96.             // the new transition will be after the previous one
  97.             data.remove(previous);
  98.             data.add(new Transition<T, D>(previous.date,      previous.getBefore(), entry));
  99.             data.add(new Transition<T, D>(latestValidityDate, entry,                previous.getAfter()));
  100.         }

  102.     }

  104.     /** Add an entry valid after a limit date.
  105.      * <p>
  106.      * As an entry is valid, it truncates the validity of the neighboring
  107.      * entries already present in the map.
  108.      * </p>
  109.      * <p>
  110.      * The transition dates should be entered only once, either
  111.      * by a call to this method or by a call to {@link #addValidBefore(Object,
  112.      * FieldAbsoluteDate)}. Repeating a transition date will lead to unexpected
  113.      * result and is not supported.
  114.      * </p>
  115.      * @param entry entry to add
  116.      * @param earliestValidityDate date after which the entry is valid
  117.      * (sould be different from <em>all</em> dates already used for transitions)
  118.      */
  119.     public void addValidAfter(final T entry, final FieldAbsoluteDate<D> earliestValidityDate) {

  121.         if (data.size() == 1) {
  122.             final Transition<T, D> single = data.first();
  123.             if (single.getBefore() == single.getAfter()) {
  124.                 // the single entry was a dummy one, without a real transition
  125.                 // we replace it entirely
  126.                 data.clear();
  127.                 data.add(new Transition<T, D>(earliestValidityDate, single.getBefore(), entry));
  128.                 return;
  129.             }
  130.         }

  132.         final Transition<T, D> next =
  133.                 data.ceiling(new Transition<T, D>(earliestValidityDate, entry, null));
  134.         if (next == null) {
  135.             // the new transition will be the last one
  136.             data.add(new Transition<T, D>(earliestValidityDate, data.last().getAfter(), entry));
  137.         } else {
  138.             // the new transition will be before the next one
  139.             data.remove(next);
  140.             data.add(new Transition<T, D>(earliestValidityDate, next.getBefore(), entry));
  141.             data.add(new Transition<T, D>(next.date,            entry,            next.getAfter()));
  142.         }

  144.     }

  146.     /** Get the entry valid at a specified date.
  147.      * @param date date at which the entry must be valid
  148.      * @return valid entry at specified date
  149.      */
  150.     public T get(final FieldAbsoluteDate<D> date) {
  151.         final Transition<T, D> previous = data.floor(new Transition<T, D>(date, null, null));
  152.         if (previous == null) {
  153.             // there are no transition before the specified date
  154.             // return the first valid entry
  155.             return data.first().getBefore();
  156.         } else {
  157.             return previous.getAfter();
  158.         }
  159.     }

  161.     /** Get an unmodifiable view of the sorted transitions.
  162.      * @return unmodifiable view of the sorted transitions
  163.      */
  164.     public SortedSet<Transition<T, D>> getTransitions() {
  165.         return Collections.unmodifiableSortedSet(data);
  166.     }

  168.     /** Local class holding transition times. */
  169.     public static class Transition<S, D extends RealFieldElement<D>> implements TimeStamped {

  171.         /** Transition date. */
  172.         private final FieldAbsoluteDate<D> date;

  174.         /** Entry valid before the transition. */
  175.         private final S before;

  177.         /** Entry valid after the transition. */
  178.         private final S after;

  180.         /** Simple constructor.
  181.          * @param date transition date
  182.          * @param before entry valid before the transition
  183.          * @param after entry valid after the transition
  184.          */
  185.         private Transition(final FieldAbsoluteDate<D> date, final S before, final S after) {
  186.             this.date   = date;
  187.             this.before = before;
  188.             this.after  = after;
  189.         }

  191.         /** Get the transition field absolute date.
  192.          * @return transition date
  193.          */
  194.         public FieldAbsoluteDate<D> getAbsoluteDate() {
  195.             return date;
  196.         }
  197.         /** Get the transition absolute date.
  198.          * @return transition date
  199.          */

  201.         public AbsoluteDate getDate() {
  202.             return date.toAbsoluteDate();
  203.         }
  204.         /** Get the entry valid before transition.
  205.          * @return entry valid before transition
  206.          */
  207.         public S getBefore() {
  208.             return before;
  209.         }

  211.         /** Get the entry valid after transition.
  212.          * @return entry valid after transition
  213.          */
  214.         public S getAfter() {
  215.             return after;
  216.         }

  218.     }



  222. }
Created with JaCoCo 0.7.9.201702052155