SSJ
V. 2.6.

umontreal.iro.lecuyer.hups
Class F2wCycleBasedLFSR

java.lang.Object
  extended by umontreal.iro.lecuyer.hups.PointSet
      extended by umontreal.iro.lecuyer.hups.CycleBasedPointSet
          extended by umontreal.iro.lecuyer.hups.CycleBasedPointSetBase2
              extended by umontreal.iro.lecuyer.hups.F2wCycleBasedLFSR

public class F2wCycleBasedLFSR
extends CycleBasedPointSetBase2

This class creates a point set based upon a linear feedback shift register sequence. The recurrence used to produce the point set is

mn = ∑i=1rbimn-i

where mnF2w, n >=  0 and biF2w. There is a polynomial in F2w[z] associated with this recurrence called the characteristic polynomial. It is

P(z) = zr + ∑i=1rbizr-i.

In the implementation, this polynomial is stored in an object F2wStructure.

Let x = (x(0),…, x(p-1))∈F2p be a p-bit vector. Let us define the function φ(x) = ∑i=1p2-ix(i-1). The point set in t dimensions produced by this class is

{(φ(y0), φ(ys),…, φ(ys(t-1)) : (v0,…,vr-1)∈F2rw}

where yn = trunch(vn,vn+1,…), vn is the representation of mn under the polynomial basis of F2w over F2, and h = w floor(31/w). The parameter s is called the stepping parameter of the recurrence.


Nested Class Summary
 
Nested classes/interfaces inherited from class umontreal.iro.lecuyer.hups.CycleBasedPointSetBase2
CycleBasedPointSetBase2.CycleBasedPointSetBase2Iterator
 
Nested classes/interfaces inherited from class umontreal.iro.lecuyer.hups.CycleBasedPointSet
CycleBasedPointSet.CycleBasedPointSetIterator
 
Constructor Summary
F2wCycleBasedLFSR(int w, int r, int modQ, int step, int nbcoeff, int[] coeff, int[] nocoeff)
          Constructs a point set with 2rw points.
F2wCycleBasedLFSR(String filename, int no)
          Constructs a point set after reading its parameters from file filename; the parameters are located at line numbered no of filename.
 
Method Summary
 String toString()
          Formats a string that contains information about the point set.
 
Methods inherited from class umontreal.iro.lecuyer.hups.CycleBasedPointSetBase2
addRandomShift, clearRandomShift, formatPoints, getCoordinate, iterator
 
Methods inherited from class umontreal.iro.lecuyer.hups.CycleBasedPointSet
getDimension
 
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

F2wCycleBasedLFSR

public F2wCycleBasedLFSR(int w,
                         int r,
                         int modQ,
                         int step,
                         int nbcoeff,
                         int[] coeff,
                         int[] nocoeff)
Constructs a point set with 2rw points. See the description of the class F2wStructure for the meaning of the parameters.


F2wCycleBasedLFSR

public F2wCycleBasedLFSR(String filename,
                         int no)
Constructs a point set after reading its parameters from file filename; the parameters are located at line numbered no of filename. The available files are listed in the description of class F2wStructure.

Method Detail

toString

public String toString()
Description copied from class: PointSet
Formats a string that contains information about the point set.

Overrides:
toString in class CycleBasedPointSet
Returns:
string representation of the point set information

SSJ
V. 2.6.

To submit a bug or ask questions, send an e-mail to Pierre L'Ecuyer.