SSJ  3.3.1
Stochastic Simulation in Java
Public Member Functions | Protected Member Functions | Protected Attributes | List of all members
SearcherKorobov Class Reference

This class implements searches to find the best Korobov lattices with respect to a given discrepancy. More...

Inheritance diagram for SearcherKorobov:
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Collaboration diagram for SearcherKorobov:
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Public Member Functions

 SearcherKorobov (Discrepancy disc, boolean primeN)
 The number of points \(n\), the dimension \(s\), and possibly the \(s\) weight factors \(\gamma_j\) must be given in disc. More...
 
double exhaust (int s)
 Exhaustive search to find the best Korobov lattice (i.e. More...
 
double exhaustPrime (int s)
 Similar to exhaust(s), except that only values of \(a\) relatively prime to \(n\) are considered.
 
double random (int s, int k)
 Random search to find the best Korobov lattice (with the smallest discrepancy) in dimension \(s\). More...
 
double randomPrime (int s, int k)
 Similar to random(s, k), except that only values of \(a\) relatively prime to \(n\) are considered.
 
int getBestA ()
 Returns the generator \(a\) of the lattice which gave the best value of the discrepancy in the last search.
 
- Public Member Functions inherited from Searcher
 Searcher (Discrepancy disc, boolean primeN)
 The number of points \(n\), the dimension \(s\), and possibly the \(s\) weight factors \(\gamma_j\) must be given in disc. More...
 
double exhaust (int s)
 Exhaustive search to find the lattice with the best (the smallest) discrepancy in dimension \(s\). More...
 
double exhaustPrime (int s)
 Similar to exhaust(s), except that only values of \(a_j\) relatively prime to \(n\) are considered.
 
double random (int s, int k)
 Random search to find the lattice with the best (the smallest) discrepancy in dimension \(s\). More...
 
double randomPrime (int s, int k)
 Similar to random(s, k), except that only values of \(a_j\) relatively prime to \(n\) are considered.
 
double getBestVal ()
 Returns the best value of the discrepancy found in the last search.
 
int [] getBestAs ()
 Returns the generator of the lattice which gave the best value of the discrepancy in the last search. More...
 
void initGen (int seed)
 Initializes the random number generator used in random searches with the starting seed seed. More...
 

Protected Member Functions

void print (int y)
 
- Protected Member Functions inherited from Searcher
void print (int[] y, int s)
 

Protected Attributes

int bestA
 
- Protected Attributes inherited from Searcher
Discrepancy disc
 
PointSet lat
 
double [] gamma
 
double bestVal
 
int [] bestAs
 
boolean primeN = false
 
boolean power2F = false
 

Additional Inherited Members

- Static Protected Attributes inherited from Searcher
static RandomStream gen = new LFSR113()
 

Detailed Description

This class implements searches to find the best Korobov lattices with respect to a given discrepancy.

Given a positive integer \(n\) and a multiplier \(a\), the points are defined by

\[ \mathbf{u}_i = (i/n)(1, a, a^2, …, a^{s-1}) \bmod1 \]

for \(i=0,…,n-1\).

The discrepancy object in the constructor must fix the number of points \(n\), the maximal dimension \(s\) of the lattice and possibly, the weight factors \(\gamma_j\). Then the search program will examine different lattices with \(n\), \(s\) and \(\gamma_j\) fixed in order to find the best amongst those examined.

Constructor & Destructor Documentation

◆ SearcherKorobov()

SearcherKorobov ( Discrepancy  disc,
boolean  primeN 
)

The number of points \(n\), the dimension \(s\), and possibly the \(s\) weight factors \(\gamma_j\) must be given in disc.

The \(n\) points of the lattice will be generated in the search. The flag primeN indicates whether \(n\) is a prime number (true) or not (false). This is used in the *Prime methods.

Member Function Documentation

◆ exhaust()

double exhaust ( int  s)

Exhaustive search to find the best Korobov lattice (i.e.

with the smallest discrepancy) in dimension \(s\). The search runs exhaustively over all values \( a = 2, 3, …, (n-1)\), where \(a\) is the generator of the lattice. The method returns the best value found for the discrepancy.

◆ random()

double random ( int  s,
int  k 
)

Random search to find the best Korobov lattice (with the smallest discrepancy) in dimension \(s\).

\(k\) random values \(a\) are examined as generator of the lattice. The \(a\) takes values over the integers \( a = 2, 3, …, (n-1)\). The method returns the best value found for the discrepancy.


The documentation for this class was generated from the following file: