java.lang.Object
org.cicirello.search.problems.ForresterEtAl2008
 All Implemented Interfaces:
Splittable<Initializer<SingleReal>>
,Initializer<SingleReal>
,OptimizationProblem<SingleReal>
,Problem<SingleReal>
public final class ForresterEtAl2008
extends Object
implements OptimizationProblem<SingleReal>, Initializer<SingleReal>
A continuous function with a single suboptimal local minimum, and a single global minimum, and a
0 derivative inflexion point, defined for inputs x in [0.0, 1.0].
This minimization problem was introduced in:
 Forrester, A.I.J.; Sóbester, A.; Keane, A.J. Appendix: Example Problems. In Engineering Design via Surrogate Modelling: A Practical Guide; John Wiley and Sons, Ltd, 2008; pp. 195–203. doi:10.1002/9780470770801.app1.
The lower fidelity variation is as defined https://www.sfu.ca/~ssurjano/forretal08.html.

Constructor Summary
ConstructorDescriptionConstructs the original version of the ForresterEtAl2008 cost function.ForresterEtAl2008
(boolean lowerFidelity) Constructs the ForresterEtAl2008 cost function. 
Method Summary
Modifier and TypeMethodDescriptiondouble
cost
(SingleReal candidate) Computes the cost of a candidate solution to the problem instance.Creates one candidate solution to a problem.split()
Generates a functionally identical copy of this object, for use in multithreaded implementations of search algorithms.double
value
(SingleReal candidate) Computes the value of the candidate solution within the usual constraints and interpretation of the problem.Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface org.cicirello.search.problems.OptimizationProblem
costAsDouble, getSolutionCostPair, isMinCost, minCost

Constructor Details

ForresterEtAl2008
public ForresterEtAl2008()Constructs the original version of the ForresterEtAl2008 cost function. 
ForresterEtAl2008
public ForresterEtAl2008(boolean lowerFidelity) Constructs the ForresterEtAl2008 cost function. Parameters:
lowerFidelity
  If false, constructs the original function. If true, constructs the lower fidelity version of the function.


Method Details

cost
Description copied from interface:OptimizationProblem
Computes the cost of a candidate solution to the problem instance. The lower the cost, the more optimal the candidate solution. Specified by:
cost
in interfaceOptimizationProblem<SingleReal>
 Parameters:
candidate
 The candidate solution to evaluate. Returns:
 The cost of the candidate solution. Lower cost means better solution.

value
Description copied from interface:OptimizationProblem
Computes the value of the candidate solution within the usual constraints and interpretation of the problem. Specified by:
value
in interfaceOptimizationProblem<SingleReal>
 Parameters:
candidate
 The candidate solution to evaluate. Returns:
 The actual optimization value of the candidate solution.

createCandidateSolution
Description copied from interface:Initializer
Creates one candidate solution to a problem. Specified by:
createCandidateSolution
in interfaceInitializer<SingleReal>
 Returns:
 a candidate solution to a problem instance.

split
Description copied from interface:Splittable
Generates a functionally identical copy of this object, for use in multithreaded implementations of search algorithms. The state of the object that is returned may or may not be identical to that of the original. Thus, this is a distinct concept from the functionality of theCopyable
interface. Classes that implement this interface must ensure that the object returned performs the same functionality, and that it does not share any state data that would be either unsafe or inefficient for concurrent access by multiple threads. The split method is allowed to simply return the this reference, provided that it is both safe and efficient for multiple threads to share a single copy of the Splittable object. The intention is to provide a multithreaded search with the capability to provide spawned threads with their own distinct search operators. Such multithreaded algorithms can call the split method for each thread it spawns to generate a functionally identical copy of the operator, but with independent state. Specified by:
split
in interfaceSplittable<Initializer<SingleReal>>
 Returns:
 A functionally identical copy of the object, or a reference to this if it is both safe and efficient for multiple threads to share a single instance of this Splittable object.
