umontreal.iro.lecuyer.hups
Class KorobovLattice

java.lang.Object
  umontreal.iro.lecuyer.hups.PointSet
      umontreal.iro.lecuyer.hups.Rank1Lattice
          umontreal.iro.lecuyer.hups.KorobovLattice

Direct Known Subclasses:

KorobovLatticeSequence

public class KorobovLattice
extends Rank1Lattice

This class implements Korobov lattices, which represents the same point sets as in class LCGPointSet, but implemented differently. The parameters are the modulus n and the multiplier a, for an arbitrary integer 1 <= a < n. [When a is outside the interval [1, n), then we replace a by (a mod n) in all calculations.] The number of points is n, their dimension is s, and they are defined by

u_i = (i/n)(1, a, a²,…, a^s-1) mod 1

for i = 0,..., n - 1.

It is also possible to build a ``shifted'' Korobov lattice with the first t coordinates rejected. The s-dimensionnal points are then defined as

u_i = (i/n)(a^t, a^t+1, a^t+2,…, a^t+s-1) mod 1

for i = 0,..., n - 1 and fixed t.

Constructor Summary

KorobovLattice(int n, int a, int s)
Instantiates a Korobov lattice point set with modulus n and multiplier a in dimension s.

KorobovLattice(int n, int a, int s, int t)
Instantiates a shifted Korobov lattice point set with modulus n and multiplier a in dimension s.

Method Summary

int	getA() Returns the multiplier a of the lattice.
void	setNumPoints(int n) Resets the number of points of the lattice to n.
String	toString() Formats a string that contains information about the point set.

Methods inherited from class umontreal.iro.lecuyer.hups.Rank1Lattice

addRandomShift, clearRandomShift, getAs, getCoordinate, iterator

Methods inherited from class umontreal.iro.lecuyer.hups.PointSet

addRandomShift, addRandomShift, addRandomShift, formatPoints, formatPoints, formatPoints, formatPoints, formatPointsBase, formatPointsBase, formatPointsBase, formatPointsBase, formatPointsNumbered, formatPointsNumbered, getDimension, getNumPoints, getStream, randomize, randomize, randomize, randomize, randomize, setStream, unrandomize

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

KorobovLattice

public KorobovLattice(int n,
                      int a,
                      int s)

Instantiates a Korobov lattice point set with modulus n and multiplier a in dimension s.

KorobovLattice

public KorobovLattice(int n,
                      int a,
                      int s,
                      int t)

Instantiates a shifted Korobov lattice point set with modulus n and multiplier a in dimension s. The first t coordinates of a standard Korobov lattice are dropped as described above. The case t = 0 corresponds to the standard Korobov lattice.

Method Detail

setNumPoints

public void setNumPoints(int n)

Resets the number of points of the lattice to n. The values of s, a and t are unchanged.

Overrides:

setNumPoints in class Rank1Lattice

getA

public int getA()

Returns the multiplier a of the lattice. (The original one before it is reset to a mod n).

toString

public String toString()

Description copied from class: PointSet

Formats a string that contains information about the point set.

Overrides:

toString in class Rank1Lattice

Returns:

string representation of the point set information