Class RealValueInitializer
 java.lang.Object

 org.cicirello.search.operators.reals.RealValueInitializer

 All Implemented Interfaces:
Splittable<Initializer<SingleReal>>
,Initializer<SingleReal>
public class RealValueInitializer extends Object implements Initializer<SingleReal>
Generating randomSingleReal
objects for use in generating random initial solutions for simulated annealing and other metaheuristics, and for copying such objects. This initializer supports both unbounded objects (SingleReal
) as well as bounded reals, where the domain of values is bound in an interval. In the bounded case, the objects created by this class enforce the bounds upon calls toSingleReal.set(double)
such that theSingleReal.set(double)
method will set the value to the min if a value is passed less than min (and similarly for max).


Constructor Summary
Constructors Constructor Description RealValueInitializer(double a, double b)
Construct a RealValueInitializer that generates random solutions uniformly in the interval [a, b).RealValueInitializer(double a, double b, double min, double max)
Construct a RealValueInitializer that generates random solutions uniformly in the interval [a, b), subject to bounds [min, max].

Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description SingleReal
createCandidateSolution()
Creates one candidate solution to a problem.boolean
equals(Object other)
int
hashCode()
RealValueInitializer
split()
Generates a functionally identical copy of this object, for use in multithreaded implementations of search algorithms.



Constructor Detail

RealValueInitializer
public RealValueInitializer(double a, double b)
Construct a RealValueInitializer that generates random solutions uniformly in the interval [a, b). TheSingleReal
objects returned by thecreateCandidateSolution()
method are otherwise unbounded (i.e., future mutations may alter the value such that it leaves that interval). Use the other constructor if you need to enforce bounds. Parameters:
a
 The lower end of the interval (inclusive).b
 The upper end of the interval (exclusive). Throws:
IllegalArgumentException
 if a ≥ b

RealValueInitializer
public RealValueInitializer(double a, double b, double min, double max)
Construct a RealValueInitializer that generates random solutions uniformly in the interval [a, b), subject to bounds [min, max]. If this constructor is used, then thecreateCandidateSolution()
method will return an object of a subclass ofSingleReal
, which will enforce the constraint that the value of the function inputs must remain in the interval [min, max] as mutation and other operators are applied. Parameters:
a
 The lower end of the interval (inclusive).b
 The upper end of the interval (exclusive).min
 Lower bound on allowed values for the function inputs generated.max
 Upper bound on allowed values for the function inputs generated. Throws:
IllegalArgumentException
 if a ≥ b


Method Detail

createCandidateSolution
public final SingleReal 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
public RealValueInitializer 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.

