[boost] random: missed seed() method

8 Apr 2004

      Hi,

to fulfill Jens Maurers wg21-proposal (C++ TR proposal)  for random number
facilities,
 a "Pseudo-random number engine" has to implement a 'seed()' method as
written in 
chapter IV, "Proposed Text". Some of the boost generators don't implement
this 
method, these are

* linear_feedback_shift
* additive_combine
* inversive_congruential
* discard_block
* shuffle_output

I added the missing method as seen in the diff quotes below.
To test the changes I used the post-condition which has to be fulfilled
after seed()
has been called, namely u.seed() == X()   (same state as after default
constructor called)

//
test's
//****************************************************************************
  ecuyer1988 ec, ec1;
  rngTest.register_rng<ecuyer1988>("Ecuyer 1988"); 
  ec.seed();
  if (ec == ec1)
    std::cout << "* additive_combine -> OK \n";
  else
    std::cout << "- additive_combine \n";

  taus88 taus;
  rngTest.register_rng<taus88>("Tausworthe 88");
  taus.seed();
  taus88 taus1;
  if (taus == taus1)
    std::cout << "* linear_feedback -> OK \n";
  else
    std::cout << "- linear_feedback \n";

  boost::hellekalek1995 helle, helle1;
  rngTest.register_rng<boost::hellekalek1995>("Hellekalek 1995");
  helle.seed();
  if (helle == helle1)
    std::cout << "* inverse_cong -> OK \n";
  else
    std::cout << "- inverse_cong \n";

  boost::ranlux64_3_01 ranlux, ranlux1;
  rngTest.register_rng<boost::ranlux64_3_01>("RanLux 64 Base");
  ranlux.seed();
  if (ranlux == ranlux1)
    std::cout << "* discard_block -> OK \n";
  else
    std::cout << "- discard_block \n";

  boost::kreutzer1986 kreutz, kreutz1;
  rngTest.register_rng<boost::kreutzer1986>("Kreutzers Generator");
  kreutz.seed();
  if (kreutz == kreutz1)
    std::cout << "* shuffle_output -> OK \n";
  else
    std::cout << "- shuffle_output
\n";
//****************************************************************************

output:
* additive_combine -> OK
* linear_feedback -> OK
* inverse_cong -> OK
* discard_block -> OK
* shuffle_output -> OK

Bye Mario Ruetti

Index: linear_feedback_shift.hpp
===================================================================
RCS file: /cvsroot/boost/boost/boost/random/linear_feedback_shift.hpp,v
retrieving revision 1.7
diff -r1.7 linear_feedback_shift.hpp
83c83
<   void seed(UIntType s0) { assert(s0 >= (1 << (w-k))); value = s0; }
---
...
void seed(UIntType s0 = 341) { assert(s0 >= (1 << (w-k))); value = s0; }
Index: additive_combine.hpp
===================================================================
RCS file: /cvsroot/boost/boost/boost/random/additive_combine.hpp,v
retrieving revision 1.5
diff -r1.5 additive_combine.hpp
62a63,68
...
void seed()
  {
    _mlcg1.seed();
    _mlcg2.seed();
  }
Index: inversive_congruential.hpp
===================================================================
RCS file: /cvsroot/boost/boost/boost/random/inversive_congruential.hpp,v
retrieving revision 1.6
diff -r1.6 inversive_congruential.hpp
63c63
<   void seed(IntType y0) { value = y0; if(b == 0) assert(y0 > 0); }
---
...
void seed(IntType y0 = 1) { value = y0; if(b == 0) assert(y0 > 0); }
Index: discard_block.hpp
===================================================================
RCS file: /cvsroot/boost/boost/boost/random/discard_block.hpp,v
retrieving revision 1.7
diff -r1.7 discard_block.hpp
52a53
...
void seed() { _rng.seed(); _n = 0; }
Index: shuffle_output.hpp
===================================================================
RCS file: /cvsroot/boost/boost/boost/random/shuffle_output.hpp,v
retrieving revision 1.6
diff -r1.6 shuffle_output.hpp
65a66
...
void seed() { _rng.seed(); init(); }
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