View Javadoc
1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF 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    *      https://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  /*
19   * This is not the original file distributed by the Apache Software Foundation
20   * It has been modified by the Hipparchus project
21   */
22  package org.hipparchus.linear;
23  
24  /**
25   * Marker class for RealVectors that require sparse backing storage
26   * <p>
27   *  Caveat: Implementation are allowed to assume that, for any {@code x},
28   *  the equality {@code x * 0d == 0d} holds. But it is is not true for
29   *  {@code NaN}. Moreover, zero entries will lose their sign.
30   *  Some operations (that involve {@code NaN} and/or infinities) may
31   *  thus give incorrect results, like multiplications, divisions or
32   *  functions mapping.
33   * </p>
34   */
35  public abstract class SparseRealVector extends RealVector {
36  
37      /** Empty constructor.
38       * <p>
39       * This constructor is not strictly necessary, but it prevents spurious
40       * javadoc warnings with JDK 18 and later.
41       * </p>
42       * @since 3.0
43       */
44      public SparseRealVector() { // NOPMD - unnecessary constructor added intentionally to make javadoc happy
45          // nothing to do
46      }
47  
48  } // NOPMD - this is an intentional marker class