SSJ
V. 2.6.

umontreal.iro.lecuyer.hups
Class F2wStructure

java.lang.Object
  extended by umontreal.iro.lecuyer.hups.F2wStructure

public class F2wStructure
extends Object

This class implements methods and fields needed by the classes F2wNetLFSR, F2wNetPolyLCG, F2wCycleBasedLFSR and F2wCycleBasedPolyLCG. It also stores the parameters of these point sets which will contain 2rw points (see the meaning of r and w below). The parameters can be stored as a polynomial P(z) over F2w[z]

P(z) = zr + ∑i=1rbizr-i

where biF2w for i = 1,…, r. Let ζ be the root of an irreducible polynomial Q(z)∈F2[z]. It is well known that ζ is a generator of the finite field F2w. The elements of F2w are represented using the polynomial ordered basis (1, ζ,…, ζw-1).

In this class, only the non-zero coefficients of P(z) are stored. It is stored as

P(z) = zr + ∑i=0nbcoeffcoeff[i]znocoeff[i]

where the coefficients in coeff[] represent the non-zero coefficients bi of P(z) using the polynomial basis. The finite field F2w used is defined by the polynomial

Q(z) = zw + ∑i=1waizw-i

where aiF2, for i = 1,…, w. Polynomial Q is stored as the bit vector modQ = (aw,…, a1).

The class also stores the parameter step that is used by the classes F2wNetLFSR, F2wNetPolyLCG, F2wCycleBasedLFSR and F2wCycleBasedPolyLCG. This parameter is such that the implementation of the recurrence will output a value at every step iterations.


Method Summary
static void print(String filename)
          Prints the content of file filename.
 String toString()
          This method returns a string containing the polynomial P(z) and the stepping parameter.
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Method Detail

print

public static void print(String filename)
Prints the content of file filename. See the constructor above for the conditions on filename.


toString

public String toString()
This method returns a string containing the polynomial P(z) and the stepping parameter.

Overrides:
toString in class Object

SSJ
V. 2.6.

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