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 package org.apache.commons.math4.legacy.optim.linear;
18
19 import org.apache.commons.math4.legacy.optim.OptimizationData;
20
21 /**
22 * Pivot selection rule to the use for a Simplex solver.
23 *
24 * @since 3.3
25 */
26 public enum PivotSelectionRule implements OptimizationData {
27 /**
28 * The classical rule, the variable with the most negative coefficient
29 * in the objective function row will be chosen as entering variable.
30 */
31 DANTZIG,
32 /**
33 * The first variable with a negative coefficient in the objective function
34 * row will be chosen as entering variable. This rule guarantees to prevent
35 * cycles, but may take longer to find an optimal solution.
36 */
37 BLAND
38 }