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 */ 017package org.apache.commons.math4.optim.linear; 018 019import org.apache.commons.math4.optim.OptimizationData; 020 021/** 022 * Pivot selection rule to the use for a Simplex solver. 023 * 024 * @since 3.3 025 */ 026public enum PivotSelectionRule implements OptimizationData { 027 /** 028 * The classical rule, the variable with the most negative coefficient 029 * in the objective function row will be chosen as entering variable. 030 */ 031 DANTZIG, 032 /** 033 * The first variable with a negative coefficient in the objective function 034 * row will be chosen as entering variable. This rule guarantees to prevent 035 * cycles, but may take longer to find an optimal solution. 036 */ 037 BLAND 038}