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* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
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package org.apache.commons.math4.optim.linear;
import java.util.ArrayList;
import java.util.Collection;
import org.apache.commons.math4.TestUtils;
import org.apache.commons.math4.optim.linear.LinearConstraint;
import org.apache.commons.math4.optim.linear.LinearObjectiveFunction;
import org.apache.commons.math4.optim.linear.Relationship;
import org.apache.commons.math4.optim.linear.SimplexTableau;
import org.apache.commons.math4.optim.nonlinear.scalar.GoalType;
import org.junit.Assert;
import org.junit.Test;
public class SimplexTableauTest {
@Test
public void testInitialization() {
LinearObjectiveFunction f = createFunction();
Collection<LinearConstraint> constraints = createConstraints();
SimplexTableau tableau =
new SimplexTableau(f, constraints, GoalType.MAXIMIZE, false, 1.0e-6);
double[][] expectedInitialTableau = {
{-1, 0, -1, -1, 2, 0, 0, 0, -4},
{ 0, 1, -15, -10, 25, 0, 0, 0, 0},
{ 0, 0, 1, 0, -1, 1, 0, 0, 2},
{ 0, 0, 0, 1, -1, 0, 1, 0, 3},
{ 0, 0, 1, 1, -2, 0, 0, 1, 4}
};
assertMatrixEquals(expectedInitialTableau, tableau.getData());
}
@Test
public void testDropPhase1Objective() {
LinearObjectiveFunction f = createFunction();
Collection<LinearConstraint> constraints = createConstraints();
SimplexTableau tableau =
new SimplexTableau(f, constraints, GoalType.MAXIMIZE, false, 1.0e-6);
double[][] expectedTableau = {
{ 1, -15, -10, 0, 0, 0, 0},
{ 0, 1, 0, 1, 0, 0, 2},
{ 0, 0, 1, 0, 1, 0, 3},
{ 0, 1, 1, 0, 0, 1, 4}
};
tableau.dropPhase1Objective();
assertMatrixEquals(expectedTableau, tableau.getData());
}
@Test
public void testTableauWithNoArtificialVars() {
LinearObjectiveFunction f = new LinearObjectiveFunction(new double[] {15, 10}, 0);
Collection<LinearConstraint> constraints = new ArrayList<>();
constraints.add(new LinearConstraint(new double[] {1, 0}, Relationship.LEQ, 2));
constraints.add(new LinearConstraint(new double[] {0, 1}, Relationship.LEQ, 3));
constraints.add(new LinearConstraint(new double[] {1, 1}, Relationship.LEQ, 4));
SimplexTableau tableau =
new SimplexTableau(f, constraints, GoalType.MAXIMIZE, false, 1.0e-6);
double[][] initialTableau = {
{1, -15, -10, 25, 0, 0, 0, 0},
{0, 1, 0, -1, 1, 0, 0, 2},
{0, 0, 1, -1, 0, 1, 0, 3},
{0, 1, 1, -2, 0, 0, 1, 4}
};
assertMatrixEquals(initialTableau, tableau.getData());
}
@Test
public void testSerial() {
LinearObjectiveFunction f = createFunction();
Collection<LinearConstraint> constraints = createConstraints();
SimplexTableau tableau =
new SimplexTableau(f, constraints, GoalType.MAXIMIZE, false, 1.0e-6);
Assert.assertEquals(tableau, TestUtils.serializeAndRecover(tableau));
}
private LinearObjectiveFunction createFunction() {
return new LinearObjectiveFunction(new double[] {15, 10}, 0);
}
private Collection<LinearConstraint> createConstraints() {
Collection<LinearConstraint> constraints = new ArrayList<>();
constraints.add(new LinearConstraint(new double[] {1, 0}, Relationship.LEQ, 2));
constraints.add(new LinearConstraint(new double[] {0, 1}, Relationship.LEQ, 3));
constraints.add(new LinearConstraint(new double[] {1, 1}, Relationship.EQ, 4));
return constraints;
}
private void assertMatrixEquals(double[][] expected, double[][] result) {
Assert.assertEquals("Wrong number of rows.", expected.length, result.length);
for (int i = 0; i < expected.length; i++) {
Assert.assertEquals("Wrong number of columns.", expected[i].length, result[i].length);
for (int j = 0; j < expected[i].length; j++) {
Assert.assertEquals("Wrong value at position [" + i + "," + j + "]", expected[i][j], result[i][j], 1.0e-15);
}
}
}
}