Class RealVectorInitializer
 java.lang.Object

 org.cicirello.search.operators.reals.RealVectorInitializer

 All Implemented Interfaces:
Splittable<Initializer<RealVector>>
,Initializer<RealVector>
public final class RealVectorInitializer extends Object implements Initializer<RealVector>
Generates randomRealVector
objects for use in generating random initial solutions for simulated annealing and other metaheuristics, and for copying such objects. This initializer supports both unbounded vectors (RealVector
) as well as bounded vectors, 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 toRealVector.set(int, double)
such that theRealVector.set(int, 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 RealVectorInitializer(double[] a, double[] b)
Construct a RealVectorInitializer that generates random solutions such that the values of variable i is chosen uniformly in the interval [a[i], b[i]).RealVectorInitializer(double[] a, double[] b, double[] min, double[] max)
Construct a RealVectorInitializer that generates random solutions such that the values of variable i is chosen uniformly in the interval [a[i], b[i]), subject to bounds [min[i], max[i]].RealVectorInitializer(double[] a, double[] b, double min, double max)
Construct a RealVectorInitializer that generates random solutions such that the values of variable i is chosen uniformly in the interval [a[i], b[i]), subject to bounds [min, max].RealVectorInitializer(int n, double a, double b)
Construct a RealVectorInitializer that generates random solutions such that the values of all n variables are chosen uniformly in the interval [a, b).RealVectorInitializer(int n, double a, double b, double min, double max)
Construct a RealVectorInitializer that generates random solutions such that the values of all n variables are chosen uniformly in the interval [a, b), subject to bounds [min, max].

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



Constructor Detail

RealVectorInitializer
public RealVectorInitializer(int n, double a, double b)
Construct a RealVectorInitializer that generates random solutions such that the values of all n variables are chosen uniformly in the interval [a, b). TheRealVector
objects returned by thecreateCandidateSolution()
method are otherwise unbounded (i.e., future mutations may alter the values such that it leaves that interval). Use a different constructor if you need to enforce bounds. Parameters:
n
 The number of input variables for the function.a
 The lower end of the interval (inclusive).b
 The upper end of the interval (exclusive). Throws:
IllegalArgumentException
 if a ≥ bNegativeArraySizeException
 if n < 0

RealVectorInitializer
public RealVectorInitializer(double[] a, double[] b)
Construct a RealVectorInitializer that generates random solutions such that the values of variable i is chosen uniformly in the interval [a[i], b[i]). TheRealVector
objects returned by thecreateCandidateSolution()
method are otherwise unbounded (i.e., future mutations may alter the values such that it leaves that interval). Use a different constructor if you need to enforce bounds. Parameters:
a
 An array of the left points of the intervals, inclusive. The length of this array corresponds to the number of input variables for the function you are optimizing. Variable x[i]'s initial value will be at least a[i].b
 An array of the right points of the intervals, exclusive. The length of this array corresponds to the number of input variables for the function you are optimizing. Variable x[i]'s initial value will be less than b[i]. Throws:
IllegalArgumentException
 if the lengths of a and b are different, or if there exists an i, such that a[i] ≥ b[i].

RealVectorInitializer
public RealVectorInitializer(int n, double a, double b, double min, double max)
Construct a RealVectorInitializer that generates random solutions such that the values of all n variables are chosen 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 ofRealVector
, which will enforce the constraint that the values of the function inputs must remain in the interval [min, max] as mutation and other operators are applied. Parameters:
n
 The number of input variables for the function.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 or if min > maxNegativeArraySizeException
 if n < 0

RealVectorInitializer
public RealVectorInitializer(double[] a, double[] b, double min, double max)
Construct a RealVectorInitializer that generates random solutions such that the values of variable i is chosen uniformly in the interval [a[i], b[i]), subject to bounds [min, max]. If this constructor is used, then thecreateCandidateSolution()
method will return an object of a subclass ofRealVector
, which will enforce the constraint that the values of the function inputs must remain in the interval [min, max] as mutation and other operators are applied. Parameters:
a
 An array of the left points of the intervals, inclusive. The length of this array corresponds to the number of input variables for the function you are optimizing. Variable x[i]'s initial value will be at least a[i].b
 An array of the right points of the intervals, exclusive. The length of this array corresponds to the number of input variables for the function you are optimizing. Variable x[i]'s initial value will be less than b[i].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 the lengths of a and b are different; or if there exists an i, such that a[i] ≥ b[i]; or if min > max.

RealVectorInitializer
public RealVectorInitializer(double[] a, double[] b, double[] min, double[] max)
Construct a RealVectorInitializer that generates random solutions such that the values of variable i is chosen uniformly in the interval [a[i], b[i]), subject to bounds [min[i], max[i]]. If this constructor is used, then thecreateCandidateSolution()
method will return an object of a subclass ofRealVector
, which will enforce the constraint that the values of the function inputs must remain in the interval [min[i], max[i]] as mutation and other operators are applied. Parameters:
a
 An array of the left points of the intervals, inclusive. The length of this array corresponds to the number of input variables for the function you are optimizing. Variable x[i]'s initial value will be at least a[i].b
 An array of the right points of the intervals, exclusive. The length of this array corresponds to the number of input variables for the function you are optimizing. Variable x[i]'s initial value will be less than b[i].min
 An array of lower bounds on allowed values for the function inputs generated, such that x[i] will never be less than min[i].max
 An array of upper bounds on allowed values for the function inputs generated, such that x[i] will never be greater than max[i]. Throws:
IllegalArgumentException
 if the lengths of a and b are different; or if there exists an i, such that a[i] ≥ b[i] or min[i] > max[i].


Method Detail

createCandidateSolution
public final RealVector createCandidateSolution()
Description copied from interface:Initializer
Creates one candidate solution to a problem. Specified by:
createCandidateSolution
in interfaceInitializer<RealVector>
 Returns:
 a candidate solution to a problem instance.

split
public RealVectorInitializer 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<RealVector>>
 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.

