1   /* Copyright 2022-2025 Luc Maisonobe
2    * Licensed to CS GROUP (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  
18  package org.orekit.files.ccsds.ndm.adm.acm;
19  
20  import java.util.List;
21  
22  import org.hipparchus.linear.DiagonalMatrix;
23  import org.orekit.time.AbsoluteDate;
24  import org.orekit.time.TimeStamped;
25  import org.orekit.utils.units.Unit;
26  
27  /** Covariance entry.
28   * @author Luc Maisonobe
29   * @since 12.0
30   */
31  public class AttitudeCovariance implements TimeStamped {
32  
33      /** Type of the elements. */
34      private final AttitudeCovarianceType type;
35  
36      /** Entry date. */
37      private final AbsoluteDate date;
38  
39      /** Covariance matrix. */
40      private final DiagonalMatrix matrix;
41  
42      /** Simple constructor.
43       * @param type type of the elements
44       * @param date entry date
45       * @param fields matrix diagonal elements
46       * @param first index of first field to consider
47       */
48      public AttitudeCovariance(final AttitudeCovarianceType type, final AbsoluteDate date,
49                                final String[] fields, final int first) {
50          final List<Unit> units = type.getUnits();
51          this.type   = type;
52          this.date   = date;
53          this.matrix = new DiagonalMatrix(units.size());
54          for (int k = 0; k < matrix.getRowDimension(); ++k) {
55              matrix.setEntry(k, k, units.get(k).toSI(Double.parseDouble(fields[first + k])));
56          }
57      }
58  
59      /** {@inheritDoc} */
60      @Override
61      public AbsoluteDate getDate() {
62          return date;
63      }
64  
65      /** Get the covariance matrix.
66       * @return covariance matrix
67       */
68      public DiagonalMatrix getMatrix() {
69          return matrix;
70      }
71  
72      /** Get the type of the elements.
73       * @return type of the elements
74       */
75      public AttitudeCovarianceType getType() {
76          return type;
77      }
78  
79  }