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1   /*
2    * Copyright (C) 2018 Alberto Irurueta Carro (alberto@irurueta.com)
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *         http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package com.irurueta.navigation.indoor;
17  
18  import com.irurueta.algebra.Matrix;
19  import com.irurueta.geometry.Point;
20  
21  /**
22   * Contains a located signal strength reading associated to a given radio source
23   * (e.g. Wi-Fi access point or bluetooth beacon).
24   *
25   * @param <S> a {@link RadioSource} type.
26   * @param <P> a {@link Point} type.
27   */
28  public class RssiReadingLocated<S extends RadioSource, P extends Point<?>> extends RssiReading<S> implements
29          ReadingLocated<P> {
30  
31      /**
32       * Position where radio source reading was made.
33       */
34      private P position;
35  
36      /**
37       * Covariance of inhomogeneous coordinates of current position
38       * (if available).
39       */
40      private Matrix positionCovariance;
41  
42      /**
43       * Constructor.
44       *
45       * @param source   radio source associated to this reading.
46       * @param rssi     received signal strength indicator in dBm.
47       * @param position position where reading was made.
48       * @throws IllegalArgumentException if either radio source data or position
49       *                                  are null.
50       */
51      public RssiReadingLocated(final S source, final double rssi, final P position) {
52          super(source, rssi);
53  
54          if (position == null) {
55              throw new IllegalArgumentException();
56          }
57  
58          this.position = position;
59      }
60  
61      /**
62       * Constructor.
63       *
64       * @param source                radio source associated to this reading.
65       * @param rssi                  received signal strength indicator in dBm.
66       * @param position              position where reading was made.
67       * @param rssiStandardDeviation standard deviation of RSSI, if available.
68       * @throws IllegalArgumentException if either radio source data or position
69       *                                  are null.
70       */
71      public RssiReadingLocated(final S source, final double rssi, final P position, final Double rssiStandardDeviation) {
72          super(source, rssi, rssiStandardDeviation);
73  
74          if (position == null) {
75              throw new IllegalArgumentException();
76          }
77  
78          this.position = position;
79      }
80  
81      /**
82       * Constructor.
83       *
84       * @param source             radio source associated to this reading.
85       * @param rssi               received signal strength indicator in dBm.
86       * @param position           position where reading was made.
87       * @param positionCovariance covariance of inhomogeneous coordinates of
88       *                           current position (if available).
89       * @throws IllegalArgumentException if either radio source or position are
90       *                                  null, or covariance has invalid size.
91       */
92      public RssiReadingLocated(final S source, final double rssi, final P position, final Matrix positionCovariance) {
93          this(source, rssi, position);
94  
95          if (positionCovariance != null) {
96              final var dims = position.getDimensions();
97              if (positionCovariance.getRows() != dims || positionCovariance.getColumns() != dims) {
98                  throw new IllegalArgumentException();
99              }
100         }
101         this.positionCovariance = positionCovariance;
102     }
103 
104     /**
105      * Constructor.
106      *
107      * @param source                radio source associated to this reading.
108      * @param rssi                  received signal strength indicator in dBm.
109      * @param position              position where reading was made.
110      * @param rssiStandardDeviation standard deviation of RSSI, if available.
111      * @param positionCovariance    covariance of inhomogeneous coordinates of
112      *                              current position (if available).
113      * @throws IllegalArgumentException if either radio source or position are
114      *                                  null, or covariance has invalid size.
115      */
116     public RssiReadingLocated(
117             final S source, final double rssi, final P position, final Double rssiStandardDeviation,
118             final Matrix positionCovariance) {
119         this(source, rssi, position, rssiStandardDeviation);
120 
121         if (positionCovariance != null) {
122             var dims = position.getDimensions();
123             if (positionCovariance.getRows() != dims || positionCovariance.getColumns() != dims) {
124                 throw new IllegalArgumentException();
125             }
126         }
127         this.positionCovariance = positionCovariance;
128     }
129 
130     /**
131      * Empty constructor.
132      */
133     protected RssiReadingLocated() {
134         super();
135     }
136 
137     /**
138      * Gets position where reading was made.
139      *
140      * @return position where reading was made.
141      */
142     @Override
143     public P getPosition() {
144         return position;
145     }
146 
147     /**
148      * Gets covariance of inhomogeneous coordinates of current position (if available).
149      *
150      * @return covariance of position or null.
151      */
152     @Override
153     public Matrix getPositionCovariance() {
154         return positionCovariance;
155     }
156 }