Class: Random::MersenneTwister

Inherits:
RandomNumberGenerator
  • Object
show all
Defined in:
ext/random/mersenne_twister_ext.c

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ Object

Initialize an instance of the Mersenne Twister RNG. The seed can either be a 32 bit unsigned integer (ie a Ruby Integer in the range 0..(-1+2**32)) or an array of 624 32 bit unsigned integers (the state used by the Mersenne Twister algorithm). If an array larger than 624 is given only the first 624 integers are used. If no seed is used we use a (fixed) default value.



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# File 'ext/random/mersenne_twister_ext.c', line 272

static VALUE
mt_initialize(int argc, VALUE* argv, VALUE self) {
  MersenneTwister* mt;
  VALUE arg_seed;
  register int i;
  uint32 array_seed[N];
  uint32 oneSeed;
  uint32 max;

  Data_Get_Struct(self, MersenneTwister, mt);

  rb_scan_args(argc, argv, "01", &arg_seed);

  // Get a new seed if none were given
  if(TYPE(arg_seed) == T_NIL) {
    arg_seed = UINT2NUM(hash(time(NULL), clock()));
  }

  switch (TYPE(arg_seed)) {

  case T_ARRAY:
    // Find max number of numbers in seed array
    if (RARRAY(arg_seed)->len < N)
      max = RARRAY(arg_seed)->len;
    else
      max = N;

    // Translate Ruby Integers to uint32s
    for( i = 0; i<max; i++) {
      array_seed[i] = NUM2UINT(rb_ary_entry(arg_seed, i));
    }
    for(; i<N; i++) {
      array_seed[i] = (uint32)0;
    }

    // Then seed from that
    seed_from_array(mt, array_seed, max);
    break;
    
  case T_BIGNUM:
  case T_FIXNUM:
    seed(mt, (uint32)NUM2UINT(arg_seed));
    break;

  default:
    rb_raise(rb_eException, "Invalid argument");
    break;
  }
  
  return self;
}

Instance Method Details

#gen_uint32 ⇒ Object 



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# File 'ext/random/mersenne_twister_ext.c', line 333

static VALUE
mt_gen_uint32(VALUE self)
{
  MersenneTwister *mt;

  Data_Get_Struct(self, MersenneTwister, mt);

  return UINT2NUM(rand_int(mt));
}

#marshal_dump ⇒ Object 



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# File 'ext/random/mersenne_twister_ext.c', line 376

static VALUE
mt_state(VALUE self)
{
  register VALUE ary;
  register const uint32 *s;
  register int i = N;
  MersenneTwister *mt;

  Data_Get_Struct(self, MersenneTwister, mt);

  s = mt->state;
  ary  = rb_ary_new();

  for( ; i--; s++) {
    rb_ary_push(ary, UINT2NUM(*s));
  }

  rb_ary_push(ary, UINT2NUM(mt->left));

  //printf("get: left=%u, s-n=%u, s[0]=%u, s[623]=%u\n", 
  //	 mt->left, mt->pNext - mt->state, mt->state[0], mt->state[623]);

  return ary;
}

#marshal_load(ary) ⇒ Object 



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# File 'ext/random/mersenne_twister_ext.c', line 401

static VALUE
mt_state_set(VALUE self, VALUE ary)
{
  register uint32 *s;
  register int i = N;
  MersenneTwister *mt;

  Data_Get_Struct(self, MersenneTwister, mt);

  s = mt->state;

  for(i = 0; i < N; s++) {
    *s = NUM2UINT(rb_ary_entry(ary, i++));
  }

  mt->left = NUM2UINT(rb_ary_entry(ary, i));
  mt->pNext = &(mt->state[N-mt->left]);

  //  printf("set: left=%u, s-n=%u, s[0]=%u, s[623]=%u\n", 
  //	 mt->left, mt->pNext - mt->state, mt->state[0], mt->state[623]);

  return ary;
}

#next ⇒ Object 



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# File 'ext/random/mersenne_twister_ext.c', line 333

static VALUE
mt_gen_uint32(VALUE self)
{
  MersenneTwister *mt;

  Data_Get_Struct(self, MersenneTwister, mt);

  return UINT2NUM(rand_int(mt));
}

#rand_float ⇒ Object 



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# File 'ext/random/mersenne_twister_ext.c', line 358

static VALUE
mt_rand_float(VALUE self)
{
  MersenneTwister *mt;
  
  Data_Get_Struct(self, MersenneTwister, mt);
  return rb_float_new(rand_double(mt));
}

#rand_float_excl ⇒ Object 



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# File 'ext/random/mersenne_twister_ext.c', line 367

static VALUE
mt_rand_float_excl(VALUE self)
{
  MersenneTwister *mt;
  
  Data_Get_Struct(self, MersenneTwister, mt);
  return rb_float_new(rand_double_excl(mt));
}

#rand_int_small_limited(limit) ⇒ Object 



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# File 'ext/random/mersenne_twister_ext.c', line 343

static VALUE
mt_rand_int_small_limited(VALUE self, VALUE limit)
{
  uint32 lim = NUM2UINT(limit);
  MersenneTwister *mt;

  if(lim == 0) {
    return UINT2NUM(0);
  }

  Data_Get_Struct(self, MersenneTwister, mt);

  return UINT2NUM(rand_int_small_limited(mt, lim));
}

#state ⇒ Object 



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# File 'ext/random/mersenne_twister_ext.c', line 376

static VALUE
mt_state(VALUE self)
{
  register VALUE ary;
  register const uint32 *s;
  register int i = N;
  MersenneTwister *mt;

  Data_Get_Struct(self, MersenneTwister, mt);

  s = mt->state;
  ary  = rb_ary_new();

  for( ; i--; s++) {
    rb_ary_push(ary, UINT2NUM(*s));
  }

  rb_ary_push(ary, UINT2NUM(mt->left));

  //printf("get: left=%u, s-n=%u, s[0]=%u, s[623]=%u\n", 
  //	 mt->left, mt->pNext - mt->state, mt->state[0], mt->state[623]);

  return ary;
}

#state=(ary) ⇒ Object 



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# File 'ext/random/mersenne_twister_ext.c', line 401

static VALUE
mt_state_set(VALUE self, VALUE ary)
{
  register uint32 *s;
  register int i = N;
  MersenneTwister *mt;

  Data_Get_Struct(self, MersenneTwister, mt);

  s = mt->state;

  for(i = 0; i < N; s++) {
    *s = NUM2UINT(rb_ary_entry(ary, i++));
  }

  mt->left = NUM2UINT(rb_ary_entry(ary, i));
  mt->pNext = &(mt->state[N-mt->left]);

  //  printf("set: left=%u, s-n=%u, s[0]=%u, s[623]=%u\n", 
  //	 mt->left, mt->pNext - mt->state, mt->state[0], mt->state[623]);

  return ary;
}