001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 package org.apache.commons.math3.optim.linear; 018 019 /** 020 * Types of relationships between two cells in a Solver {@link LinearConstraint}. 021 * 022 * @version $Id: Relationship.java 1416643 2012-12-03 19:37:14Z tn $ 023 * @since 2.0 024 */ 025 public enum Relationship { 026 /** Equality relationship. */ 027 EQ("="), 028 /** Lesser than or equal relationship. */ 029 LEQ("<="), 030 /** Greater than or equal relationship. */ 031 GEQ(">="); 032 033 /** Display string for the relationship. */ 034 private final String stringValue; 035 036 /** 037 * Simple constructor. 038 * 039 * @param stringValue Display string for the relationship. 040 */ 041 private Relationship(String stringValue) { 042 this.stringValue = stringValue; 043 } 044 045 @Override 046 public String toString() { 047 return stringValue; 048 } 049 050 /** 051 * Gets the relationship obtained when multiplying all coefficients by -1. 052 * 053 * @return the opposite relationship. 054 */ 055 public Relationship oppositeRelationship() { 056 switch (this) { 057 case LEQ : 058 return GEQ; 059 case GEQ : 060 return LEQ; 061 default : 062 return EQ; 063 } 064 } 065 }