Class: GMP::RandState

Inherits:
Object
  • Object
show all
Defined in:
ext/gmp.c,
ext/gmprandstate.c

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ Object 



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# File 'ext/gmprandstate.c', line 101

VALUE r_gmprandstate_initialize(int argc, VALUE *argv, VALUE self)
{
  MP_RANDSTATE *self_val;
  (void)argv;

  if (argc != 0) {
    mprandstate_get_struct(self,self_val);
  }
  return Qnil;
}

Class Method Details

.GMP::RandState.new ⇒ Object .GMP::RandState.new(: mt) ⇒ Object .GMP::RandState.new(: lc_2exp, a, c, m2exp) ⇒ Object .GMP::RandState.new(: lc_2exp_size, size) ⇒ Object

Initializes a new Random State object. Multiple GMP::RandState objects can be instantiated. They may use different generators and the states are kept separate.



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# File 'ext/gmprandstate.c', line 40

VALUE r_gmprandstatesg_new(int argc, VALUE *argv, VALUE klass)
{
  MP_RANDSTATE *rs_val;
  VALUE rs;
  VALUE algorithm, arg2, arg3, arg4;
  ID algorithm_id = rb_intern("default");
  MP_INT *a_val = NULL;
  unsigned long c_val, m2exp_val;
  unsigned long size_val;
  int free_a_val = 0;

  ID default_algorithm      = rb_intern("default");
  ID mt_algorithm           = rb_intern("mt");
  ID lc_2exp_algorithm      = rb_intern("lc_2exp");
  ID lc_2exp_size_algorithm = rb_intern("lc_2exp_size");

  (void)klass;

  mprandstate_make_struct(rs, rs_val);
  rb_scan_args(argc, argv, "04", &algorithm, &arg2, &arg3, &arg4);
  if (NIL_P(algorithm))    { algorithm_id = rb_intern("default"); }  /* default value */
  if (SYMBOL_P(algorithm)) { algorithm_id = rb_to_id(algorithm); }
  if (algorithm_id == default_algorithm ||
      algorithm_id == mt_algorithm) {
    if (argc > 1)
      rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 or 1)", argc);
    gmp_randinit_default(rs_val);
  } else if (algorithm_id == lc_2exp_algorithm) {
    if (argc != 4)
      rb_raise(rb_eArgError, "wrong number of arguments (%d for 4)", argc);
    if (GMPZ_P(arg2)) {
      mpz_get_struct(arg2, a_val);
    } else if (FIXNUM_P(arg2)) {
      mpz_temp_alloc(a_val);
      mpz_init_set_ui(a_val, FIX2INT(arg2));
      free_a_val = 1;
    } else if (BIGNUM_P(arg2)) {
      mpz_temp_from_bignum(a_val, arg2);
      free_a_val = 1;
    } else {
      typeerror_as(ZXB, "b");
    }
    c_val     = NUM2LONG(arg3);
    m2exp_val = NUM2LONG(arg4);
    gmp_randinit_lc_2exp(rs_val, a_val, c_val, m2exp_val);
  } else if (algorithm_id == lc_2exp_size_algorithm) {
    if (argc != 2)
      rb_raise(rb_eArgError, "wrong number of arguments (%d for 2)", argc);
    size_val = NUM2LONG(arg2);
    if (size_val > 128)
      rb_raise(rb_eArgError, "size must be within [0..128]");
    if (gmp_randinit_lc_2exp_size (rs_val, size_val) == 0)
      rb_raise(rb_eArgError, "could not gmp_randinit_lc_2exp_size with %lu", size_val);
  }

  if (free_a_val) { mpz_temp_free(a_val); }
  rb_obj_call_init(rs, argc, argv);

  return rs;
}

Instance Method Details

#mpfr_urandom ⇒ Object

From the MPFR Manual:

> Generate a uniformly distributed random float. The floating-point number > ‘rop` can be seen as if a random real number is generated according to the > continuous uniform distribution on the interval [0, 1] and then rounded in > the direction `RNDN`.

Since:

  • 0.6.47



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# File 'ext/gmprandstate.c', line 335

VALUE r_gmprandstate_mpfr_urandom(int argc, VALUE *argv, VALUE self_val)
{
  MP_RANDSTATE *self;
  MP_FLOAT *res;
  mp_rnd_t rnd_mode;
  VALUE res_val, prec_val, rnd_mode_val;
  unsigned long int prec = 0;

  mprandstate_get_struct (self_val, self);

  rb_scan_args (argc, argv, "02", &rnd_mode_val, &prec_val);
  if (NIL_P (rnd_mode_val)) { rnd_mode = __gmp_default_rounding_mode; }
  else { rnd_mode = r_get_rounding_mode(rnd_mode_val); }

  if (NIL_P (prec_val)) {
    prec = mpfr_get_default_prec();
  } else if (FIXNUM_P (prec_val)) {
    if (FIX2INT (prec_val) < 2)
      rb_raise (rb_eRangeError, "precision must be at least 2");

    prec = FIX2INT (prec_val);
  } else {
    rb_raise (rb_eTypeError, "precision must be a Fixnum");
  }

  mpf_make_struct (res_val, res);
  mpf_init2 (res, prec);

  mpfr_urandom (res, self, rnd_mode);

  return res_val;
}

#mpfr_urandomb ⇒ Object

From the MPFR Manual:

> Generate a uniformly distributed random float in the interval > _0 <= rop < 1_.



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# File 'ext/gmprandstate.c', line 289

VALUE r_gmprandstate_mpfr_urandomb(int argc, VALUE *argv, VALUE self_val)
{
  MP_RANDSTATE *self;
  MP_FLOAT *res;
  VALUE res_val;
  unsigned long prec = 0;

  if (argc > 1)
    rb_raise (rb_eArgError, "wrong number of arguments (%d for 0 or 1)", argc);

  mprandstate_get_struct (self_val, self);

  if (argc == 1) {
    if (FIXNUM_P (argv[0])) {
      if (FIX2INT (argv[0]) < 2)
        rb_raise (rb_eRangeError, "precision must be at least 2");

      prec = FIX2INT (argv[0]);
    } else {
      rb_raise (rb_eTypeError, "precision must be a Fixnum");
    }
  }

  mpf_make_struct (res_val, res);
  if (prec == 0) { mpf_init (res); }
  else           { mpf_init2 (res, prec); }

  mpfr_urandomb (res, self);

  return res_val;
}

#rrandomb(Fixnum) ⇒ Object

From the GMP Manual:

> Generate a random integer with long strings of zeros and ones in the > binary representation. Useful for testing functions and algorithms, since > this kind of random numbers have proven to be more likely to trigger > corner-case bugs. The random number will be in the range 0 to _2^n-1_, > inclusive.



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# File 'ext/gmprandstate.c', line 256

VALUE r_gmprandstate_rrandomb(VALUE self, VALUE arg)
{
  MP_RANDSTATE *self_val;
  MP_INT *res_val;
  VALUE res = 0;

  mprandstate_get_struct(self,self_val);

  if (FIXNUM_P(arg)) {
    mpz_make_struct_init(res, res_val);
    mpz_rrandomb(res_val, self_val, FIX2INT(arg));
  } else {
    typeerror(X);
  }

  return res;
}

#seed(integer) ⇒ Object

From the GMP Manual:

> Set an initial seed value into state.

> The size of a seed determines how many different sequences of random > numbers that it’s possible to generate. The “quality” of the seed is the > randomness of a given seed compared to the previous seed used, and this > affects the randomness of separate number sequences. The method for > choosing a seed is critical if the generated numbers are to be used for > important applications, such as generating cryptographic keys.

> Traditionally the system time has been used to seed, but care needs to be > taken with this. If an application seeds often and the resolution of the > system clock is low, then the same sequence of numbers might be repeated. > Also, the system time is quite easy to guess, so if unpredictability is > required then it should definitely not be the only source for the seed > value. On some systems there’s a special device ‘/dev/random` which > provides random data better suited for use as a seed.



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# File 'ext/gmprandstate.c', line 152

VALUE r_gmprandstate_seed(VALUE self, VALUE arg)
{
  MP_RANDSTATE *self_val;
  MP_INT *arg_val;

  mprandstate_get_struct(self,self_val);

  if (GMPZ_P(arg)) {
    mpz_get_struct(arg,arg_val);
    gmp_randseed(self_val, arg_val);
  } else if (FIXNUM_P(arg)) {
    gmp_randseed_ui(self_val, FIX2INT(arg));
  } else if (BIGNUM_P(arg)) {
    mpz_temp_from_bignum(arg_val, arg);
    gmp_randseed(self_val, arg_val);
  } else {
    typeerror(ZXB);
  }
  return arg;
}

#urandomb(Fixnum) ⇒ Object

From the GMP Manual:

> Generate a uniformly distributed random integer in the range 0 to > _2^fixnum-1_, inclusive.



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# File 'ext/gmprandstate.c', line 187

VALUE r_gmprandstate_urandomb(VALUE self, VALUE arg)
{
  MP_RANDSTATE *self_val;
  MP_INT *res_val;
  VALUE res = 0;

  mprandstate_get_struct(self,self_val);

  if (FIXNUM_P(arg)) {
    mpz_make_struct_init(res, res_val);
    mpz_urandomb(res_val, self_val, FIX2INT(arg));
  } else {
    typeerror(X);
  }

  return res;
}

#urandomm(integer) ⇒ Object

From the GMP Manual:

> Generate a uniformly distributed random integer in the range 0 to > integer-1, inclusive. integer can be an instance of GMP::Z, Fixnum, or > Bignum



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# File 'ext/gmprandstate.c', line 215

VALUE r_gmprandstate_urandomm(VALUE self, VALUE arg)
{
  MP_RANDSTATE *self_val;
  MP_INT *res_val, *arg_val = NULL;
  int free_arg_val = 0;
  VALUE res;

  mprandstate_get_struct(self,self_val);

  if (GMPZ_P(arg)) {
    mpz_get_struct(arg, arg_val);
  } else if (FIXNUM_P(arg)) {
    mpz_temp_alloc(arg_val);
    mpz_init_set_ui(arg_val, FIX2INT(arg));
    free_arg_val = 1;
  } else if (BIGNUM_P(arg)) {
    mpz_temp_from_bignum(arg_val, arg);
    free_arg_val = 1;
  } else {
    typeerror_as(ZXB, "arg");
  }

  mpz_make_struct_init(res, res_val);
  mpz_urandomm(res_val, self_val, arg_val);
  if (free_arg_val) { mpz_temp_free(arg_val); }

  return res;
}