SSJ  3.3.1
Stochastic Simulation in Java
Classes | Public Member Functions | Protected Attributes | List of all members
CycleBasedPointSetBase2 Class Referenceabstract

Similar to CycleBasedPointSet, except that the successive values in the cycles are stored as integers in the range \(\{0,\dots,2^k-1\}\), where \(1\le k \le31\). More...

Inheritance diagram for CycleBasedPointSetBase2:
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Collaboration diagram for CycleBasedPointSetBase2:
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Classes

class  CycleBasedPointSetBase2Iterator
 

Public Member Functions

double getCoordinate (int i, int j)
 
PointSetIterator iterator ()
 
void addRandomShift (int d1, int d2, RandomStream stream)
 Adds a random digital shift in base 2 to all the points of the point set, using stream stream to generate the random numbers, for coordinates d1 to d2 - 1. More...
 
void clearRandomShift ()
 Erases the current digital random shift, if any.
 
String formatPoints ()
 
- Public Member Functions inherited from CycleBasedPointSet
double getCoordinate (int i, int j)
 
void addRandomShift (int d1, int d2, RandomStream stream)
 Same as the same method in PointSet. More...
 
void clearRandomShift ()
 Erases the current random shift, if any.
 
int getDimension ()
 
PointSetIterator iterator ()
 
String toString ()
 
String formatPoints ()
 
- Public Member Functions inherited from PointSet
int getDimension ()
 Returns the dimension (number of available coordinates) of the points. More...
 
int getNumPoints ()
 Returns the number of points. More...
 
abstract double getCoordinate (int i, int j)
 Returns \(u_{i,j}\), the coordinate \(j\) of the point \(i\). More...
 
PointSetIterator iterator ()
 Constructs and returns a point set iterator. More...
 
void randomize (PointSetRandomization rand)
 Randomizes this point set using the given rand. More...
 
void addRandomShift (int d1, int d2, RandomStream stream)
 By default, this method generates a random shift in the protected double[] array shift, to be used eventually for a random shift modulo 1. More...
 
void addRandomShift (RandomStream stream)
 Same as addRandomShift(0, dim, stream), where dim is the dimension of the point set. More...
 
void addRandomShift (int d1, int d2)
 Refreshes the random shift (generates new uniform values for the random shift coordinates) for coordinates d1 to d2-1, using the saved shiftStream.
 
void addRandomShift ()
 Same as addRandomShift(0, dim), where dim is the dimension of the point set.
 
void clearRandomShift ()
 Erases the current random shift, if any.
 
String toString ()
 Formats a string that contains information about the point set. More...
 
String formatPoints ()
 Same as invoking formatPoints(n, d) with \(n\) and \(d\) equal to the number of points and the dimension of this object, respectively. More...
 
String formatPoints (int n, int d)
 Formats a string that displays the same information as returned by toString, together with the first \(d\) coordinates of the first \(n\) points. More...
 
String formatPoints (PointSetIterator iter)
 Same as invoking formatPoints(iter, n, d) with \(n\) and \(d\) equal to the number of points and the dimension, respectively. More...
 
String formatPoints (PointSetIterator iter, int n, int d)
 Same as invoking formatPoints(n, d), but prints the points by calling iter repeatedly. More...
 
String formatPointsBase (int b)
 Similar to formatPoints(), but the points coordinates are printed in base \(b\). More...
 
String formatPointsBase (int n, int d, int b)
 Similar to formatPoints(n, d), but the points coordinates are printed in base \(b\). More...
 
String formatPointsBase (PointSetIterator iter, int b)
 Similar to formatPoints(iter), but the points coordinates are printed in base \(b\). More...
 
String formatPointsBase (PointSetIterator iter, int n, int d, int b)
 Similar to formatPoints(iter, n, d), but the points coordinates are printed in base \(b\). More...
 
String formatPointsNumbered ()
 Same as invoking formatPointsNumbered(n, d) with \(n\) and \(d\) equal to the number of points and the dimension, respectively. More...
 
String formatPointsNumbered (int n, int d)
 Same as invoking formatPoints(n,d), except that the points are numbered. More...
 

Protected Attributes

int numBits
 
double normFactor
 
- Protected Attributes inherited from CycleBasedPointSet
int numCycles = 0
 
ObjectArrayList cycles = new ObjectArrayList()
 
- Protected Attributes inherited from PointSet
double EpsilonHalf = 1.0 / Num.TWOEXP[55]
 To avoid 0 for nextCoordinate when random shifting, we add this to each coordinate.
 
int dim = 0
 Dimension of the points.
 
int numPoints = 0
 Number of points.
 
int dimShift = 0
 Current dimension of the shift. More...
 
int capacityShift = 0
 Number of array elements in the shift vector, always >= dimShift.
 
double [] shift
 This is the shift vector as a double[] array, which contains the current random shift in case we apply a random shift modulo 1. More...
 
RandomStream shiftStream
 Stream used to generate the random shifts. More...
 

Additional Inherited Members

- Protected Member Functions inherited from CycleBasedPointSet
void addCycle (AbstractList c)
 Adds the cycle c to the list of all cycles. More...
 
- Static Protected Attributes inherited from PointSet
static final int MAXBITS = 31
 Since Java has no unsigned type, the 32nd bit cannot be used efficiently, so we have only 31 bits. More...
 

Detailed Description

Similar to CycleBasedPointSet, except that the successive values in the cycles are stored as integers in the range \(\{0,\dots,2^k-1\}\), where \(1\le k \le31\).

The output values \(u_{i,j}\) are obtained by dividing these integer values by \(2^k\). Point sets where the successive coordinates of each point are obtained via linear recurrences modulo 2 (e.g., linear feedback shift registers or Korobov-type polynomial lattice rules) are naturally expressed in this form. Storing the integers \(2^k u_{i,j}\) instead of the \(u_{i,j}\) themselves makes it easier to apply randomizations such as digital random shifts in base 2, which are applied to the bits before transforming the value to a real number \(u_{i,j}\). When a random digital shift is performed, it applies a bitwise exclusive-or of all the points with a single random point.

Member Function Documentation

◆ addRandomShift()

void addRandomShift ( int  d1,
int  d2,
RandomStream  stream 
)

Adds a random digital shift in base 2 to all the points of the point set, using stream stream to generate the random numbers, for coordinates d1 to d2 - 1.

This applies a bitwise exclusive-or of all the points with a single random point.


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