SSJ
3.2.1
Stochastic Simulation in Java
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This container class caches a point set by precomputing and storing its points locally in an array. More...
Classes | |
class | CachedPointSetIterator |
Public Member Functions | |
CachedPointSet (PointSet P, int fromPoint, int toPoint, int fromDim, int toDim) | |
Creates a new PointSet object that contains an array storing the coordinates fromDim (inclusive) to toDim (exclusive) of the points numbered fromPoint (inclusive) to toPoint (exclusive) of P . More... | |
CachedPointSet (PointSet P, int n, int dim) | |
Same as CachedPointSet(P, 0, n, 0, dim). | |
CachedPointSet (PointSet P) | |
Creates a new PointSet object that contains an array storing the points of P . More... | |
PointSetIterator | iterator () |
Constructs and returns a point set iterator which gets the values directly from the array. | |
void | setRandomizeParent (boolean randomizeParent) |
If randomizeParent is true , calls to randomize() will be defered to the parent point set (this is the default); otherwise, the randomize method of the PointSetRandomization instance is invoked with this CachedPointSet instance as its argument. | |
void | addRandomShift (int d1, int d2, RandomStream stream) |
Add the shift to the contained point set and re-caches the points. More... | |
void | randomize (PointSetRandomization rand) |
Randomizes the underlying point set using rand and re-caches the points. More... | |
void | sortByCoordinate (int j) |
Sorts the cached points by increasing order of coordinate j . More... | |
void | stripCoordinates (int d) |
Removes the first d coordinates of each cached point. More... | |
String | toString () |
double | getCoordinate (int i, int j) |
double [][] | getArray () |
PointSet | getParentPointSet () |
Returns the reference point set that was passed to the constructor. | |
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int | getDimension () |
Returns the dimension (number of available coordinates) of the point set. 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 | setStream (RandomStream stream) |
Sets the random stream used to generate random shifts to stream . More... | |
RandomStream | getStream () |
Returns the random stream used to generate random shifts. More... | |
void | randomize (PointSetRandomization rand) |
Randomizes the point set using the given rand . More... | |
void | addRandomShift (int d1, int d2, RandomStream stream) |
This method does nothing for this generic class. More... | |
void | addRandomShift (RandomStream stream) |
This method does nothing for this generic class. More... | |
void | addRandomShift (int d1, int d2) |
Similar to addRandomShift(d1, d2, stream) , with the current random stream. | |
void | addRandomShift () |
Similar to addRandomShift(0, d2, stream) with the current random stream and d2 the dimension of the current random shift. | |
void | clearRandomShift () |
Erases the current random shift, if any. | |
void | randomize (int fromDim, int toDim, RandomStream stream) |
By default, this method simply calls addRandomShift (fromDim, toDim, stream) , which does nothing. | |
void | randomize (RandomStream stream) |
By default, this method simply calls randomize(0, dim, stream). | |
void | randomize (int d1, int d2) |
By default, this method simply calls addRandomShift(d1, d2) . | |
void | randomize () |
By default, this method simply calls addRandomShift() . | |
void | unrandomize () |
By default, this method simply calls clearRandomShift() . | |
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 Member Functions | |
void | fillCache (int fromDim, int dim) |
Protected Attributes | |
PointSet | P |
double | x [][] |
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double | EpsilonHalf = 1.0 / Num.TWOEXP[55] |
int | dim = 0 |
int | numPoints = 0 |
int | dimShift = 0 |
int | capacityShift = 0 |
RandomStream | shiftStream |
Package Functions | |
public< T > void | sort (MultiDimSort< T > sort) |
Sorts the cached points (only) with the given umontreal.ssj.util.MultiDimSort sorting algorithm sort . More... | |
Package Attributes | |
int | fromPoint = 0 |
int | fromDim = 0 |
boolean | randomizeParent = true |
Additional Inherited Members | |
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static final int | MAXBITS = 31 |
This container class caches a point set by precomputing and storing its points locally in an array.
This can be used to speed up computations when using a small low-dimensional point set more than once. Some types of point sets are also implemented directly as subclasses of this one, without having a contained point set P
.
After the points are stored in the array, this class uses the default methods and the default iterator type provided by the base class PointSet. This iterator relies exclusively on the #getCoordinate method. This is one (simple) special case where direct use of #getCoordinate is efficient.
x[i][j]
instead of calling getCoordinate
, for slightly better efficiency. On the other hand, even better efficiency can be achieved by getting an entire point at a time in an array.However, it may require too much memory for a large point set.
There is a #sort(m) ethod available to sort the cached points via a and umontreal.ssj.util.MultiDimSort, and a #stripCoordinates(m) ethod that remove some coordinates of the cached points. Those methods affect only the array where the points are cached; they have no impact on the (underlying) original point set. The #randomize(m) ethod, on the other hand, randomizes the underlying point set P
and re-caches them.
CachedPointSet | ( | PointSet | P, |
int | fromPoint, | ||
int | toPoint, | ||
int | fromDim, | ||
int | toDim | ||
) |
Creates a new PointSet
object that contains an array storing the coordinates fromDim
(inclusive) to toDim
(exclusive) of the points numbered fromPoint
(inclusive) to toPoint
(exclusive) of P
.
Thus, the cached points have dim = fromDim - toDim
coordinates and there are \(n = \mathtt{toPoint}-\mathtt{fromPoint}\) of them. The original point set P
itself is not modified.
P | point set to be cached |
fromPoint | number of skipped points (usually 0) |
toPoint | 1 + number of the last point selected from P |
fromDim | number of skipped coordinates (often 0) |
toDim | 1 + index of last coordinate in the original points |
CachedPointSet | ( | PointSet | P | ) |
Creates a new PointSet
object that contains an array storing the points of P
.
The number of points and their dimension are the same as in the original point set. Both must be finite.
P | point set to be cached |
void addRandomShift | ( | int | d1, |
int | d2, | ||
RandomStream | stream | ||
) |
Add the shift to the contained point set and re-caches the points.
See the doc of the overridden method addRandomShift(d1, d2, stream) in PointSet. In case there is no underlying point set, this method must be redefined to randomize the cached points.
void randomize | ( | PointSetRandomization | rand | ) |
Randomizes the underlying point set using rand
and re-caches the points.
In case there is no underlying point set, this method must be redefined to randomize the cached points. If setRandomizeParent() was called with false
as its argument, invokes randomize() on rand
instead of on the parent.
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package |
Sorts the cached points (only) with the given umontreal.ssj.util.MultiDimSort sorting algorithm sort
.
This does not affect the underlying point set P
.
void sortByCoordinate | ( | int | j | ) |
Sorts the cached points by increasing order of coordinate j
.
This is useful in the ArrayRQMC simulation method, for example. Note that the sort applies only to the cached points, and not to the original points in P
.
void stripCoordinates | ( | int | d | ) |
Removes the first d
coordinates of each cached point.
This does not affect the underlying point set P
. This could be useful in particular for the ArrayRQMC simulation method.