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.optim.linear;
23
24 /**
25 * Types of relationships between two cells in a Solver {@link LinearConstraint}.
26 *
27 */
28 public enum Relationship {
29 /** Equality relationship. */
30 EQ("="),
31 /** Lesser than or equal relationship. */
32 LEQ("<="),
33 /** Greater than or equal relationship. */
34 GEQ(">=");
35
36 /** Display string for the relationship. */
37 private final String stringValue;
38
39 /**
40 * Simple constructor.
41 *
42 * @param stringValue Display string for the relationship.
43 */
44 Relationship(String stringValue) {
45 this.stringValue = stringValue;
46 }
47
48 /** {@inheritDoc} */
49 @Override
50 public String toString() {
51 return stringValue;
52 }
53
54 /**
55 * Gets the relationship obtained when multiplying all coefficients by -1.
56 *
57 * @return the opposite relationship.
58 */
59 public Relationship oppositeRelationship() {
60 switch (this) {
61 case LEQ :
62 return GEQ;
63 case GEQ :
64 return LEQ;
65 default :
66 return EQ;
67 }
68 }
69 }