umontreal.iro.lecuyer.hups
Class CycleBasedPointSet

java.lang.Object
  umontreal.iro.lecuyer.hups.PointSet
      umontreal.iro.lecuyer.hups.CycleBasedPointSet

Direct Known Subclasses:

CycleBasedPointSetBase2, LCGPointSet

public abstract class CycleBasedPointSet
extends PointSet

This abstract class provides the basic structures for storing and manipulating a highly uniform point set defined by a set of cycles. The s-dimensional points are all the vectors of s successive values found in any of the cycles, from any starting point. Since this is defined for any positive integer s, the points effectively have an infinite number of dimensions. The number of points, n, is the sum of lengths of all the cycles. The cycles of the point set are simply stored as a list of arrays, where each array contains the successive values for a given cycle. By default, the values are stored in double.

This structure is convenient for implementing recurrence-based point sets, where the point set in s dimensions is defined as the set of all vectors of s successive values of a periodic recurrence, from all its possible initial states.

Nested Class Summary

class

CycleBasedPointSet.CycleBasedPointSetIterator

Constructor Summary

CycleBasedPointSet()

Method Summary

void	addRandomShift(int d1, int d2, RandomStream stream) Adds a random shift to all the points of the point set, using stream stream to generate the random numbers, for coordinates d1 to d2 - 1.
void	clearRandomShift() Erases the current random shift, if any.
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.
double	getCoordinate(int i, int j) Returns ui, j, the coordinate j of the point i.
int	getDimension() Returns the dimension (number of available coordinates) of the point set.
PointSetIterator	iterator() Constructs and returns a point set iterator.
String	toString() Formats a string that contains information about the point set.

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

addRandomShift, addRandomShift, addRandomShift, formatPoints, formatPoints, formatPoints, formatPointsBase, formatPointsBase, formatPointsBase, formatPointsBase, formatPointsNumbered, formatPointsNumbered, 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

CycleBasedPointSet

public CycleBasedPointSet()

Method Detail

getCoordinate

public double getCoordinate(int i,
                            int j)

Description copied from class: PointSet

Returns u_{i, j}, the coordinate j of the point i.

Specified by:

getCoordinate in class PointSet

Parameters:

i - index of the point to look for

j - index of the coordinate to look for

Returns:

the value of u_{i, j}

addRandomShift

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

Adds a random shift to all the points of the point set, using stream stream to generate the random numbers, for coordinates d1 to d2 - 1. This applies an addition modulo 1 of a single random point to all the points.

Overrides:

addRandomShift in class PointSet

Parameters:

stream - Stream used to generate random numbers

clearRandomShift

public void clearRandomShift()

Description copied from class: PointSet

Erases the current random shift, if any.

Overrides:

clearRandomShift in class PointSet

getDimension

public int getDimension()

Description copied from class: PointSet

Returns the dimension (number of available coordinates) of the point set. If the dimension is actually infinite, Integer.MAX_VALUE is returned.

Overrides:

getDimension in class PointSet

Returns:

the dimension of the point set or Integer.MAX_VALUE if it is infinite

iterator

public PointSetIterator iterator()

Description copied from class: PointSet

Constructs and returns a point set iterator. The default implementation returns an iterator that uses the method getCoordinate (i,j) to iterate over the points and coordinates, but subclasses can reimplement it for better efficiency.

Overrides:

iterator in class PointSet

Returns:

point set iterator for the point set

toString

public String toString()

Description copied from class: PointSet

Formats a string that contains information about the point set.

Overrides:

toString in class PointSet

Returns:

string representation of the point set information

formatPoints

public String formatPoints()

Description copied from class: PointSet

Same as invoking formatPoints(n, d) with n and d equal to the number of points and the dimension of this object, respectively.

Overrides:

formatPoints in class PointSet

Returns:

string representation of all the points in the point set