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 * 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.apache.commons.math4.legacy.linear;
19
20 import org.apache.commons.math4.legacy.exception.MathIllegalArgumentException;
21 import org.apache.commons.math4.legacy.exception.util.LocalizedFormats;
22
23 /**
24 * Exception to be thrown when a self-adjoint {@link RealLinearOperator}
25 * is expected.
26 * Since the coefficients of the matrix are not accessible, the most
27 * general definition is used to check that A is not self-adjoint, i.e.
28 * there exist x and y such as {@code | x' A y - y' A x | >= eps},
29 * where {@code eps} is a user-specified tolerance, and {@code x'}
30 * denotes the transpose of {@code x}.
31 * In the terminology of this exception, {@code A} is the "offending"
32 * linear operator, {@code x} and {@code y} are the first and second
33 * "offending" vectors, respectively.
34 *
35 * @since 3.0
36 */
37 public class NonSelfAdjointOperatorException
38 extends MathIllegalArgumentException {
39 /** Serializable version Id. */
40 private static final long serialVersionUID = 1784999305030258247L;
41
42 /** Creates a new instance of this class. */
43 public NonSelfAdjointOperatorException() {
44 super(LocalizedFormats.NON_SELF_ADJOINT_OPERATOR);
45 }
46 }