org.moeaframework.problem
Class RotatedProblem

java.lang.Object
  org.moeaframework.problem.RotatedProblem

All Implemented Interfaces:

Problem

public class RotatedProblem
extends Object
implements Problem

Decorator to create rotated instances of test problems. The rotation is defined by a rotation matrix, which should be orthogonal and have a determinant of 1. See RotationMatrixBuilder for a utility to quickly construct rotation matrices.

Regardless of the rotation, all rotated instances use expanded lower and upper bounds for the decision variables. An additional constraint is added to account for solutions existing in this expanded region, which are not in the original unrotated problem. This expansion is consistent across all rotations, which ensures the volume of the constraint-violating expanded region is constant across all instances of a problem.

Constructor Summary

RotatedProblem(Problem problem, org.apache.commons.math3.linear.RealMatrix rotation)
Decorates the specified problem, creating a rotated instance using the specified rotation matrix.

Method Summary

void	close() Closes any underlying resources used by this problem.
void	evaluate(Solution solution) Evaluates the solution, updating the solution's objectives in place.
String	getName() Returns the user-friendly name for this problem.
int	getNumberOfConstraints() Returns the number of constraints defined by this problem.
int	getNumberOfObjectives() Returns the number of objectives defined by this problem.
int	getNumberOfVariables() Returns the number of decision variables defined by this problem.
Solution	newSolution() Returns a new solution for this problem.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

RotatedProblem

public RotatedProblem(Problem problem,
                      org.apache.commons.math3.linear.RealMatrix rotation)

Decorates the specified problem, creating a rotated instance using the specified rotation matrix.

Parameters:

problem - the original unrotated problem

rotation - the rotation matrix

Method Detail

getName

public String getName()

Description copied from interface: Problem

Returns the user-friendly name for this problem.

Specified by:

getName in interface Problem

Returns:

the user-friendly name for this problem

getNumberOfVariables

public int getNumberOfVariables()

Description copied from interface: Problem

Returns the number of decision variables defined by this problem.

Specified by:

getNumberOfVariables in interface Problem

Returns:

the number of decision variables defined by this problem

getNumberOfObjectives

public int getNumberOfObjectives()

Description copied from interface: Problem

Returns the number of objectives defined by this problem.

Specified by:

getNumberOfObjectives in interface Problem

Returns:

the number of objectives defined by this problem

getNumberOfConstraints

public int getNumberOfConstraints()

Description copied from interface: Problem

Returns the number of constraints defined by this problem.

Specified by:

getNumberOfConstraints in interface Problem

Returns:

the number of constraints defined by this problem

evaluate

public void evaluate(Solution solution)

Description copied from interface: Problem

Evaluates the solution, updating the solution's objectives in place. Algorithms must explicitly call this method when appropriate to evaluate new solutions or reevaluate modified solutions.

Specified by:

evaluate in interface Problem

Parameters:

solution - the solution to be evaluated

newSolution

public Solution newSolution()

Description copied from interface: Problem

Returns a new solution for this problem. Implementations must initialize the variables so that the valid range of values is defined, but may leave the actual value at a default or undefined state.

Specified by:

newSolution in interface Problem

Returns:

a new solution for this problem

close

public void close()

Description copied from interface: Problem

Closes any underlying resources used by this problem. Once closed, further invocations of any methods on this problem may throw exceptions.

Specified by:

close in interface Problem