Author: luc
Date: Wed Aug 26 08:43:27 2009
New Revision: 807923
URL: http://svn.apache.org/viewvc?rev=807923&view=rev
Log:
fixed an error with negative constraints and unfeasible solution
JIRA: MATH-290
Modified:
commons/proper/math/trunk/src/main/java/org/apache/commons/math/optimization/linear/SimplexTableau.java
commons/proper/math/trunk/src/site/xdoc/changes.xml
commons/proper/math/trunk/src/test/java/org/apache/commons/math/optimization/linear/SimplexSolverTest.java
Modified:
commons/proper/math/trunk/src/main/java/org/apache/commons/math/optimization/linear/SimplexTableau.java
URL:
http://svn.apache.org/viewvc/commons/proper/math/trunk/src/main/java/org/apache/commons/math/optimization/linear/SimplexTableau.java?rev=807923&r1=807922&r2=807923&view=diff
==============================================================================
---
commons/proper/math/trunk/src/main/java/org/apache/commons/math/optimization/linear/SimplexTableau.java
(original)
+++
commons/proper/math/trunk/src/main/java/org/apache/commons/math/optimization/linear/SimplexTableau.java
Wed Aug 26 08:43:27 2009
@@ -69,7 +69,7 @@
private final LinearObjectiveFunction f;
/** Linear constraints. */
- private final Collection<LinearConstraint> constraints;
+ private final List<LinearConstraint> constraints;
/** Whether to restrict the variables to non-negative values. */
private final boolean restrictToNonNegative;
@@ -103,7 +103,7 @@
final GoalType goalType, final boolean
restrictToNonNegative,
final double epsilon) {
this.f = f;
- this.constraints = constraints;
+ this.constraints = normalizeConstraints(constraints);
this.restrictToNonNegative = restrictToNonNegative;
this.epsilon = epsilon;
this.numDecisionVariables = getNumVariables() +
(restrictToNonNegative ? 0 : 1);
@@ -123,7 +123,6 @@
protected double[][] createTableau(final boolean maximize) {
// create a matrix of the correct size
- List<LinearConstraint> constraints = getNormalizedConstraints();
int width = numDecisionVariables + numSlackVariables +
numArtificialVariables + getNumObjectiveFunctions() + 1; // + 1 is for
RHS
int height = constraints.size() + getNumObjectiveFunctions();
@@ -192,9 +191,10 @@
/**
* Get new versions of the constraints which have positive right hand
sides.
+ * @param constraints original (not normalized) constraints
* @return new versions of the constraints
*/
- public List<LinearConstraint> getNormalizedConstraints() {
+ public List<LinearConstraint>
normalizeConstraints(Collection<LinearConstraint> constraints) {
List<LinearConstraint> normalized = new ArrayList<LinearConstraint>();
for (LinearConstraint constraint : constraints) {
normalized.add(normalize(constraint));
Modified: commons/proper/math/trunk/src/site/xdoc/changes.xml
URL:
http://svn.apache.org/viewvc/commons/proper/math/trunk/src/site/xdoc/changes.xml?rev=807923&r1=807922&r2=807923&view=diff
==============================================================================
--- commons/proper/math/trunk/src/site/xdoc/changes.xml (original)
+++ commons/proper/math/trunk/src/site/xdoc/changes.xml Wed Aug 26 08:43:27 2009
@@ -39,6 +39,10 @@
</properties>
<body>
<release version="2.1" date="TBD" description="TBD">
+ <action dev="luc" type="fix" issue="MATH-290" due-to="Benjamin McCann">
+ Fixed a NullPointerException when no solution is possible and some
constraints
+ are negative
+ </action>
<action dev="luc" type="fix" issue="MATH-288" due-to="Benjamin McCann">
Fixed an error induced by entries set to 0
</action>
Modified:
commons/proper/math/trunk/src/test/java/org/apache/commons/math/optimization/linear/SimplexSolverTest.java
URL:
http://svn.apache.org/viewvc/commons/proper/math/trunk/src/test/java/org/apache/commons/math/optimization/linear/SimplexSolverTest.java?rev=807923&r1=807922&r2=807923&view=diff
==============================================================================
---
commons/proper/math/trunk/src/test/java/org/apache/commons/math/optimization/linear/SimplexSolverTest.java
(original)
+++
commons/proper/math/trunk/src/test/java/org/apache/commons/math/optimization/linear/SimplexSolverTest.java
Wed Aug 26 08:43:27 2009
@@ -18,6 +18,7 @@
package org.apache.commons.math.optimization.linear;
import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
import java.util.ArrayList;
import java.util.Collection;
@@ -74,6 +75,16 @@
}
@Test
+ public void testMath290() throws OptimizationException {
+ LinearObjectiveFunction f = new LinearObjectiveFunction(new double[] {
1, 5 }, 0 );
+ Collection<LinearConstraint> constraints = new
ArrayList<LinearConstraint>();
+ constraints.add(new LinearConstraint(new double[] { 2, 0 },
Relationship.GEQ, -1.0));
+ SimplexSolver solver = new SimplexSolver();
+ RealPointValuePair solution = solver.optimize(f, constraints,
GoalType.MINIMIZE, true);
+ assertNotNull(solution);
+ }
+
+ @Test
public void testSimplexSolver() throws OptimizationException {
LinearObjectiveFunction f =
new LinearObjectiveFunction(new double[] { 15, 10 }, 7);
