Class: GMP::Z

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

Overview

GMP Multiple Precision Integer.

Instances of this class can store variables of the type mpz_t. This class also contains many methods that act as the functions for mpz_t variables, as well as a few methods that attempt to make this library more Ruby-ish.

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ Object



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# File 'ext/gmpz.c', line 608

VALUE r_gmpz_initialize(int argc, VALUE *argv, VALUE self)
{
  MP_INT *self_val;
  int base = 0;

  // Set up the base if 2 arguments are passed
  if (argc == 2) { // only ok if String, Fixnum
    if (STRING_P(argv[0])) {  // first arg must be a String
      if (FIXNUM_P(argv[1])) {  //  second arg must be a Fixnum
        base = FIX2INT(argv[1]);
        if ( base != 0 && ( base < 2 || base > 62) )
          rb_raise (rb_eRangeError, "base must be either 0 or between 2 and 62");
      } else {
        rb_raise (rb_eTypeError, "base must be a Fixnum between 2 and 62, not a %s.", rb_class2name (rb_class_of (argv[1])));
      }
    } else {
      rb_raise(
        rb_eTypeError,
        "GMP::Z.new() must be passed a String as the 1st argument (not a %s), if a base is passed as the 2nd argument.",
        rb_class2name (rb_class_of (argv[0]))
      );
    }
  }

  if (argc != 0) {
    mpz_get_struct (self,self_val);
    mpz_set_value (self_val, argv[0], base);
  }
  return Qnil;
}

Class Method Details

.absObject

call-seq:

a.abs

Returns the absolute value of a.

.addObject

call-seq:

GMP::Z.add(rop, op1, op2)

.addmulObject

.cdiv_q_2expObject

.cdiv_r_2expObject

.comObject

call-seq:

a.com

Returns the one’s complement of a.

.congruent?Boolean

Returns:

  • (Boolean)

.divexactObject

Functional Mappings

.divisible?Boolean

Returns:

  • (Boolean)

.facObject

call-seq:

GMP::Z.fac(n)

Returns n!, the factorial of n.

Examples:

  • GMP::Z.fac(0) #=> 1

  • GMP::Z.fac(1) #=> 1

  • GMP::Z.fac(2) #=> 2

  • GMP::Z.fac(3) #=> 6

  • GMP::Z.fac(4) #=> 24

.fdiv_q_2expObject

.fdiv_r_2expObject

.fibObject

call-seq:

GMP::Z.fib(n)

Returns F[n], the nth Fibonacci number.

Examples:

  • GMP::Z.fib(1) #=> 1

  • GMP::Z.fib(2) #=> 1

  • GMP::Z.fib(3) #=> 2

  • GMP::Z.fib(4) #=> 3

  • GMP::Z.fib(5) #=> 5

  • GMP::Z.fib(6) #=> 8

  • GMP::Z.fib(7) #=> 13

.GMP::Z.jacobi(a, b) ⇒ Object

Calculate the Jacobi symbol (a/b). This is defined only for b odd and positive.



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# File 'ext/gmpz.c', line 1864

VALUE r_gmpzsg_jacobi(VALUE klass, VALUE a, VALUE b)
{
  MP_INT *a_val, *b_val;
  int res_val;
  int free_a_val = 0;
  int free_b_val = 0;
  (void)klass;
  
  if (GMPZ_P(a)) {
    mpz_get_struct(a, a_val);
  } else if (FIXNUM_P(a)) {
    mpz_temp_alloc(a_val);
    mpz_init_set_ui(a_val, FIX2NUM(a));
    free_a_val = 1;
  } else if (BIGNUM_P(a)) {
    mpz_temp_from_bignum(a_val, a);
    free_a_val = 1;
  } else {
    typeerror_as(ZXB, "a");
  }
  
  if (GMPZ_P(b)) {
    mpz_get_struct(b, b_val);
    if (mpz_sgn(b_val) != 1)
      rb_raise(rb_eRangeError, "Cannot take Jacobi symbol (a/b) where b is non-positive.");
    if (mpz_even_p(b_val))
      rb_raise(rb_eRangeError, "Cannot take Jacobi symbol (a/b) where b is even.");
  } else if (FIXNUM_P(b)) {
    if (FIX2NUM(b) <= 0)
      rb_raise(rb_eRangeError, "Cannot take Jacobi symbol (a/b) where b is non-positive.");
    if (FIX2NUM(b) % 2 == 0)
      rb_raise(rb_eRangeError, "Cannot take Jacobi symbol (a/b) where b is even.");
    mpz_temp_alloc(b_val);
    mpz_init_set_ui(b_val, FIX2NUM(b));
    free_b_val = 1;
  } else if (BIGNUM_P(b)) {
    mpz_temp_from_bignum(b_val, b);
    if (mpz_sgn(b_val) != 1) {
      mpz_temp_free(b_val);
      rb_raise(rb_eRangeError, "Cannot take Jacobi symbol (a/b) where b is non-positive.");
    }
    if (mpz_even_p(b_val)) {
      mpz_temp_free(b_val);
      rb_raise(rb_eRangeError, "Cannot take Jacobi symbol (a/b) where b is even.");
    }
    free_b_val = 1;
  } else {
    typeerror_as(ZXB, "b");
  }
  
  res_val = mpz_jacobi(a_val, b_val);
  if (free_a_val) { mpz_temp_free(a_val); }
  if (free_b_val) { mpz_temp_free(b_val); }
  return INT2FIX(res_val);
}

.lcmObject

Functional Mappings

.mulObject

.mul_2expObject

.negObject

call-seq:

a.neg
-a

Returns -a.

.newObject

Initializing, Assigning Integers

.nextprimeObject

call-seq:

n.nextprime
n.next_prime

Returns the next prime greater than n.

This function uses a probabilistic algorithm to identify primes. For practical purposes it’s adequate, the chance of a composite passing will be extremely small.

.powObject

call-seq:

GMP::Z.pow(a, b)

Returns a raised to b. The case 0^0 yields 1.

.sqrtObject

call-seq:

a.sqrt

Returns the truncated integer part of the square root of a.

.subObject

.submulObject

.tdiv_q_2expObject

.tdiv_r_2expObject

Instance Method Details

#%Object

#&Object

call-seq:

a & b

Returns a bitwise-and b. b must be an instance of one of the following:

  • GMP::Z

  • Fixnum

  • Bignum

#*(b) ⇒ Object

Multiplies a with b. a must be an instance of one of

  • GMP::Z

  • Fixnum

  • GMP::Q

  • GMP::F

  • Bignum



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# File 'ext/gmpz.c', line 1016

VALUE r_gmpz_mul(VALUE self, VALUE arg)
{
  MP_INT *self_val, *arg_val, *res_val;
  VALUE res;

  mpz_get_struct(self,self_val);

  if (GMPZ_P(arg)) {
    mpz_make_struct_init(res, res_val);
    mpz_get_struct(arg,arg_val);
    mpz_mul(res_val, self_val, arg_val);
  } else if (FIXNUM_P(arg)) {
    mpz_make_struct_init(res, res_val);
    mpz_mul_si(res_val, self_val, FIX2NUM(arg));
  } else if (GMPQ_P(arg)) {
    return r_gmpq_mul(arg, self);
  } else if (GMPF_P(arg)) {
#ifndef MPFR
    return r_gmpf_mul(arg, self);
#else
    return rb_funcall(arg, rb_intern("*"), 1, self);
#endif
  } else if (BIGNUM_P(arg)) {
    mpz_make_struct_init(res, res_val);
    mpz_set_bignum(res_val, arg);
    mpz_mul(res_val, res_val, self_val);
  } else {
    typeerror(ZQFXB);
  }
  return res;
}

#**Object

call-seq:

a ** b

Returns a raised to b. The case 0^0 yields 1.

#+(b) ⇒ Object

Adds a to b. b must be an instance of one of:

  • GMP::Z

  • Fixnum

  • GMP::Q

  • GMP::F

  • Bignum



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# File 'ext/gmpz.c', line 846

VALUE r_gmpz_add(VALUE self, VALUE arg)
{
  MP_INT *self_val, *arg_val, *res_val;
  VALUE res;

  mpz_get_struct(self,self_val);

  if (GMPZ_P(arg)) {
    mpz_get_struct(arg,arg_val);
    mpz_make_struct_init(res, res_val);
    mpz_add(res_val, self_val, arg_val);
  } else if (FIXNUM_P(arg)) {
    mpz_make_struct_init(res, res_val);
    if (FIX2NUM(arg) > 0)
      mpz_add_ui(res_val, self_val, FIX2NUM(arg));
    else
      mpz_sub_ui(res_val, self_val, -FIX2NUM(arg));
  } else if (GMPQ_P(arg)) {
    return r_gmpq_add(arg, self);
  } else if (GMPF_P(arg)) {
#ifndef MPFR
    return r_gmpf_add(arg, self);
#else
    return rb_funcall(arg, rb_intern("+"), 1, self);
#endif
  } else if (BIGNUM_P(arg)) {
    mpz_make_struct_init(res, res_val);
    mpz_init(res_val);
    mpz_set_bignum(res_val, arg);
    mpz_add(res_val, res_val, self_val);
  } else {
    typeerror(ZQFXB);
  }
  return res;
}

#-(b) ⇒ Object

Subtracts b from a. b must be an instance of one of:

  • GMP::Z

  • Fixnum

  • GMP::Q

  • GMP::F

  • Bignum



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# File 'ext/gmpz.c', line 928

VALUE r_gmpz_sub(VALUE self, VALUE arg)
{
  MP_RAT *res_val_q, *arg_val_q;
  MP_INT *self_val, *arg_val, *res_val;
  MP_FLOAT *arg_val_f, *res_val_f;
  VALUE res;
  unsigned long prec;

  mpz_get_struct(self,self_val);

  if (GMPZ_P(arg)) {
    mpz_make_struct_init(res, res_val);
    mpz_get_struct(arg,arg_val);
    mpz_sub (res_val, self_val, arg_val);
  } else if (FIXNUM_P(arg)) {
    mpz_make_struct_init(res, res_val);
    if (FIX2NUM(arg) > 0)
      mpz_sub_ui (res_val, self_val, FIX2NUM(arg));
    else
      mpz_add_ui (res_val, self_val, -FIX2NUM(arg));
  } else if (GMPQ_P(arg)) {
    mpq_make_struct_init(res, res_val_q);
    mpq_get_struct(arg,arg_val_q);
    mpz_set (mpq_denref(res_val_q), mpq_denref(arg_val_q));
    mpz_mul (mpq_numref(res_val_q), mpq_denref(arg_val_q), self_val);
    mpz_sub (mpq_numref(res_val_q), mpq_numref(res_val_q), mpq_numref(arg_val_q));
  } else if (GMPF_P(arg)) {
    mpf_get_struct_prec (arg, arg_val_f, prec);
    mpf_make_struct_init(res, res_val_f, prec);
    mpf_set_z (res_val_f, self_val);
    mpf_sub (res_val_f, res_val_f, arg_val_f);
  } else if (BIGNUM_P(arg)) {
    mpz_make_struct_init(res, res_val);
    mpz_set_bignum (res_val, arg);
    mpz_sub (res_val, self_val, res_val);
  } else {
    typeerror (ZQFXB);
  }
  return res;
}

#-@Object

#/Object

Integer Division

#<Object

call-seq:

a < b

Returns whether a is strictly less than b.

#<<Object

call-seq:

a << n

Returns a times 2 raised to n. This operation can also be defined as a left shift by n bits.

#<=Object

call-seq:

a <= b

Returns whether a is less than or equal to b.

#<=>(b) ⇒ Object

Returns negative if a is less than b.

Returns 0 if a is equal to b.

Returns positive if a is greater than b.



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# File 'ext/gmpz.c', line 2108

VALUE r_gmpz_cmp(VALUE self, VALUE arg)
{
  MP_INT *self_val;
  int res;
  mpz_get_struct(self,self_val);
  res = mpz_cmp_value(self_val, arg);
  if (res > 0)
    return INT2FIX(1);
  else if (res == 0)
    return INT2FIX(0);
  else
    return INT2FIX(-1);
}

#==Object

#>Object

call-seq:

a > b

Returns whether a is strictly greater than b.

#>=Object

call-seq:

a >= b

Returns whether a is greater than or equal to b.

#>>Object

unsorted

#[](index) ⇒ Object

Gets the bit at index, returned as either true or false.



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# File 'ext/gmpz.c', line 2426

VALUE r_gmpz_getbit(VALUE self, VALUE bitnr)
{
  MP_INT *self_val;
  unsigned long bitnr_val;
  mpz_get_struct(self, self_val);
  if (FIXNUM_P(bitnr)) {
    bitnr_val = FIX2NUM (bitnr);
  } else {
    typeerror_as(X, "index");
  }
  return mpz_tstbit(self_val, bitnr_val)?Qtrue:Qfalse;
}

#[]=(index) ⇒ Object

Sets the bit at index to x.



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# File 'ext/gmpz.c', line 2397

VALUE r_gmpz_setbit(VALUE self, VALUE bitnr, VALUE set_to)
{
  MP_INT *self_val;
  unsigned long bitnr_val;

  mpz_get_struct (self, self_val);

  if (FIXNUM_P (bitnr)) {
    if (FIX2NUM (bitnr) < 0) {
      rb_raise(rb_eRangeError, "index must be nonnegative");
    }
    bitnr_val = FIX2NUM (bitnr);
  } else {
    typeerror_as (X, "index");
  }
  if (RTEST (set_to)) {
    mpz_setbit (self_val, bitnr_val);
  } else {
    mpz_clrbit (self_val, bitnr_val);
  }
  return Qnil;
}

#^Object

call-seq:

a ^ b

Returns a bitwise exclusive-or b. b must be an instance of one of the following:

  • GMP::Z

  • Fixnum

  • Bignum

#absObject

call-seq:

a.abs

Returns the absolute value of a.

#abs!Object

call-seq:

a.abs!

Sets a to its absolute value.

#add!(_b_) ⇒ Object

Adds a to b in-place, setting a to the sum. b must be an instance of one of:

  • GMP::Z

  • Fixnum

  • GMP::Q

  • GMP::F

  • Bignum



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# File 'ext/gmpz.c', line 893

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

  mpz_get_struct(self,self_val);

  if (GMPZ_P(arg)) {
    mpz_get_struct(arg,arg_val);
    mpz_add(self_val, self_val, arg_val);
  } else if (FIXNUM_P(arg)) {
    if (FIX2NUM(arg) > 0)
      mpz_add_ui(self_val, self_val, FIX2NUM(arg));
    else
      mpz_sub_ui(self_val, self_val, -FIX2NUM(arg));
  } else if (BIGNUM_P(arg)) {
    mpz_temp_from_bignum(arg_val, arg);
    mpz_add(self_val, self_val, arg_val);
    mpz_temp_free(arg_val);
  } else {
    typeerror(ZXB);
  }
  return Qnil;
}

#addmul!(b, c) ⇒ Object

Sets a to a plus b times c. b and c must each be an instance of one of

  • GMP::Z

  • Fixnum

  • Bignum

Since:

  • 0.4.19



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# File 'ext/gmpz.c', line 1059

static VALUE r_gmpz_addmul_self(VALUE self, VALUE b, VALUE c)
{
  MP_INT *self_val, *b_val, *c_val;
  int free_b_val = 0;

  if (GMPZ_P(b)) {
    mpz_get_struct(b, b_val);
  } else if (FIXNUM_P(b)) {
    mpz_temp_alloc(b_val);
    mpz_init_set_si(b_val, FIX2NUM(b));
    free_b_val = 1;
  } else if (BIGNUM_P(b)) {
    mpz_temp_from_bignum(b_val, b);
    free_b_val = 1;
  } else {
    typeerror_as(ZXB, "addend");
  }
  mpz_get_struct(self, self_val);

  if (GMPZ_P(c)) {
    mpz_get_struct(c, c_val);
    mpz_addmul(self_val, b_val, c_val);
  } else if (FIXNUM_P(c)) {
    if (FIX2NUM(c) < 0)
    {
      if (free_b_val) { mpz_temp_free(b_val); }
      rb_raise(rb_eRangeError, "multiplicand (Fixnum) must be nonnegative");
    }
    mpz_addmul_ui(self_val, b_val, FIX2NUM(c));
  } else if (BIGNUM_P(c)) {
    mpz_temp_from_bignum(c_val, c);
    mpz_addmul(self_val, b_val, c_val);
    mpz_temp_free(c_val);
  } else {
    if (free_b_val)
      mpz_temp_free(b_val);
    typeerror_as(ZXB, "multiplicand");
  }
  if (free_b_val)
    mpz_temp_free(b_val);
  return self;
}

#cdivObject

call-seq:

n.cdiv(d)

Divide n by d, forming a quotient q. cdiv rounds q up towards _+infinity_. The c stands for “ceil”.

q will satisfy n=q*d+r.

This function calculates only the quotient.

#cmodObject

call-seq:

n.cmod(d)

Divides n by d, forming a remainder r. r will have the opposite sign of d. The c stands for “ceil”.

r will satisfy n=q*d+r, and r will satisfy 0 <= abs( r ) < abs( d ).

This function calculates only the remainder.

#cmpabsObject

#coerce(arg) ⇒ Object



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# File 'ext/gmp.c', line 23

static VALUE r_gmpz_coerce(VALUE self, VALUE arg)
{
  return rb_assoc_new(r_gmpzsg_new(1, &arg, cGMP_Z), self);
}

#comObject

call-seq:

a.com

Returns the one’s complement of a.

#com!Object

call-seq:

a.com!

Sets a to its one’s complement.

#divisible?(b) ⇒ Boolean

Returns true if a is divisible by b. b can be an instance any of the following:

  • GMP::Z

  • Fixnum

  • Bignum

Returns:

  • (Boolean)

Since:

  • 0.5.23



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# File 'ext/gmpz.c', line 1435

static VALUE r_gmpz_divisible(VALUE self, VALUE arg)
{
  MP_INT *self_val, *arg_val;
  int res;
  mpz_get_struct (self, self_val);
  
  if (FIXNUM_P (arg) && FIX2NUM (arg) > 0) {
    mpz_temp_alloc(arg_val);
    mpz_init_set_ui(arg_val, FIX2NUM(arg));
    res = mpz_divisible_ui_p (self_val, FIX2NUM (arg));
    mpz_temp_free(arg_val);
  } else if (FIXNUM_P (arg)) {
    mpz_temp_alloc(arg_val);
    mpz_make_struct_init (arg, arg_val);
    mpz_init_set_si(arg_val, FIX2NUM(arg));
    res = mpz_divisible_p (self_val, arg_val);
    mpz_temp_free(arg_val);
  } else if (BIGNUM_P (arg)) {
    mpz_temp_from_bignum(arg_val, arg);
    res = mpz_divisible_p (self_val, arg_val);
    mpz_temp_free(arg_val);
  } else if (GMPZ_P (arg)) {
    mpz_get_struct(arg, arg_val);
    res = mpz_divisible_p (self_val, arg_val);
  } else {
    typeerror_as (ZXB, "argument");
  }
  return (res != 0) ? Qtrue : Qfalse;
}

#eql?(b) ⇒ Boolean

Returns true if a is equal to b. a and b must then be equal in cardinality, and both be instances of GMP::Z. Otherwise, returns false. a.eql?(b) if and only if b.class == GMP::Z, and a.hash == b.hash.

Returns:

  • (Boolean)

Since:

  • 0.4.7



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# File 'ext/gmpz.c', line 2228

VALUE r_gmpz_eql(VALUE self, VALUE arg)
{
  MP_INT *self_val, *arg_val;
  mpz_get_struct(self,self_val);
  
  if (GMPZ_P(arg)) {
    mpz_get_struct(arg, arg_val);
    return (mpz_cmp (self_val, arg_val) == 0) ? Qtrue : Qfalse;
  }
  else {
    return Qfalse;
  }
}

#even?Boolean

call-seq:

a.even?

Determines whether a is even. Returns true or false.

Returns:

  • (Boolean)

#fdivObject

call-seq:

n.fdiv(d)

Divide n by d, forming a quotient q. fdiv rounds q down towards -infinity. The f stands for “floor”.

q will satisfy n=q*d+r.

This function calculates only the quotient.

#fmodObject

call-seq:

n.fmod(d)

Divides n by d, forming a remainder r. r will have the same sign as d. The f stands for “floor”.

r will satisfy n=q*d+r, and r will satisfy 0 <= abs( r ) < abs( d ).

This function calculates only the remainder.

The remainder can be negative, so the return value is the absolute value of the remainder.

#gcdObject

#gcdext(b) ⇒ Object

Returns the greatest common divisor of a and b, in addition to s and t, the coefficients satisfying a*s + b*t = g. g is always positive, even if one or both of a and b are negative. s and t are chosen such that abs(s) <= abs(b) and abs(t) <= abs(a).

Since:

  • 0.5.23



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# File 'ext/gmpz.c', line 1761

VALUE r_gmpz_gcdext(VALUE self, VALUE arg)
{
  MP_INT *self_val, *arg_val, *res_val, *s_val, *t_val;
  VALUE res, s, t, ary;
  int free_arg_val = 0;

  mpz_get_struct (self,self_val);

  if (GMPZ_P (arg)) {
    mpz_make_struct_init (res, res_val);
    mpz_make_struct_init (s, s_val);
    mpz_make_struct_init (t, t_val);
    mpz_get_struct (arg, arg_val);
    mpz_gcdext (res_val, s_val, t_val, self_val, arg_val);
  } else if (FIXNUM_P (arg)) {
    mpz_make_struct_init (res, res_val);
    mpz_make_struct_init (s, s_val);
    mpz_make_struct_init (t, t_val);
    mpz_temp_alloc(arg_val);
    mpz_init_set_ui(arg_val, FIX2NUM(arg));
    free_arg_val = 1;
    mpz_gcdext (res_val, s_val, t_val, self_val, arg_val);
  } else if (BIGNUM_P (arg)) {
    mpz_make_struct_init (res, res_val);
    mpz_make_struct_init (s, s_val);
    mpz_make_struct_init (t, t_val);
    mpz_set_bignum (res_val, arg);
    mpz_gcdext (res_val, s_val, t_val, res_val, self_val);
  } else {
    typeerror (ZXB);
  }
  
  if (free_arg_val)
    mpz_temp_free(arg_val);
  
  ary = rb_ary_new3(3, res, s, t);
  return ary;
}

#hashObject

Returns the computed hash value of a. This method first converts a into a String (base 10), then calls String#hash on the result, returning the hash value. a.eql?(b) if and only if b.class == GMP::Z, and a.hash == b.hash.

Since:

  • 0.4.7



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# File 'ext/gmpz.c', line 2252

VALUE r_gmpz_hash(VALUE self)
{
  ID to_s_sym = rb_intern("to_s");
  ID hash_sym = rb_intern("hash");
  return rb_funcall(rb_funcall(self, to_s_sym, 0), hash_sym, 0);
}

#invert(b) ⇒ Object

Returns the inverse of a modulo b. If the inverse exists, the return value is non-zero and the result will be non-negative and less than b. If an inverse doesn’t exist, the result is undefined.

Since:

  • 0.2.11



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# File 'ext/gmpz.c', line 1810

VALUE r_gmpz_invert(VALUE self, VALUE arg)
{
  MP_INT *self_val, *arg_val, *res_val;
  VALUE res;

  mpz_get_struct (self,self_val);

  if (GMPZ_P (arg)) {
    mpz_make_struct_init (res, res_val);
    mpz_get_struct (arg, arg_val);
    mpz_invert (res_val, self_val, arg_val);
  } else if (FIXNUM_P (arg)) {
    mpz_temp_alloc(arg_val);
    mpz_init_set_ui(arg_val, FIX2NUM(arg));
    mpz_make_struct_init (res, res_val);
    mpz_invert (res_val, self_val, arg_val);
  } else if (BIGNUM_P (arg)) {
    mpz_make_struct_init (res, res_val);
    mpz_set_bignum (res_val, arg);
    mpz_invert (res_val, res_val, self_val);
  } else {
    typeerror (ZXB);
  }
  return res;
}

#jacobi(b) ⇒ Object

Calculate the Jacobi symbol (a/b). This is defined only for b odd and positive.



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# File 'ext/gmpz.c', line 1843

VALUE r_gmpz_jacobi(VALUE self, VALUE b)
{
  MP_INT *self_val, *b_val;
  int res_val;
  mpz_get_struct(self, self_val);
  mpz_get_struct(   b,    b_val);
  if (mpz_sgn(b_val) != 1)
    rb_raise(rb_eRangeError, "Cannot take Jacobi symbol (a/b) where b is non-positive.");
  if (mpz_even_p(b_val))
    rb_raise(rb_eRangeError, "Cannot take Jacobi symbol (a/b) where b is even.");
  res_val = mpz_jacobi(self_val, b_val);
  return INT2FIX(res_val);
}

#lastbits_posObject

#lastbits_sgnObject

#legendre(p) ⇒ Object

Calculate the Legendre symbol (a/p). This is defined only for p an odd positive prime, and for such p it’s identical to the Jacobi symbol.



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# File 'ext/gmpz.c', line 1927

VALUE r_gmpz_legendre(VALUE self, VALUE p)
{
  MP_INT *self_val, *p_val;
  int res_val;
  mpz_get_struct(self, self_val);
  mpz_get_struct(   p,    p_val);
  if (mpz_sgn(p_val) != 1)
    rb_raise(rb_eRangeError, "Cannot take Legendre symbol (a/p) where p is non-positive.");
  if (mpz_even_p(p_val))
    rb_raise(rb_eRangeError, "Cannot take Legendre symbol (a/p) where p is even.");
  if (mpz_probab_prime_p(p_val, 5) == 0)
    rb_raise(rb_eRangeError, "Cannot take Legendre symbol (a/p) where p is composite.");
  res_val = mpz_legendre(self_val, p_val);
  return INT2FIX(res_val);
}

#negObject

call-seq:

a.neg
-a

Returns -a.

#neg!Object

call-seq:

a.neg!

Sets a to -a.

#nextprimeObject Also known as: next_prime

call-seq:

n.nextprime
n.next_prime

Returns the next prime greater than n.

This function uses a probabilistic algorithm to identify primes. For practical purposes it’s adequate, the chance of a composite passing will be extremely small.

#nextprime!Object Also known as: next_prime!

call-seq:

n.nextprime!
n.next_prime!

Sets n to the next prime greater than n.

This function uses a probabilistic algorithm to identify primes. For practical purposes it’s adequate, the chance of a composite passing will be extremely small.

#odd?Boolean

call-seq:

a.odd?

Determines whether a is odd. Returns true or false.

Returns:

  • (Boolean)

#popcountObject

call-seq:

a.popcount

If a >= 0, return the population count of a, which is the number of 1 bits in the binary representation. If a < 0, the number of 1s is infinite, and the return value is INT2FIX(ULONG_MAX), the largest possible unsigned long.

#power?Boolean

call-seq:

p.power?

Returns true if p is a perfect power, i.e., if there exist integers a and b, with b > 1, such that p equals a raised to the power b.

Under this definition both 0 and 1 are considered to be perfect powers. Negative values of integers are accepted, but of course can only be odd perfect powers.

Returns:

  • (Boolean)

#powmod(b, c) ⇒ Object

Returns a raised to b modulo c.

Negative b is supported if an inverse a^-1 mod c exists. If an inverse doesn’t exist then a divide by zero is raised.



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# File 'ext/gmpz.c', line 1515

VALUE r_gmpz_powm(VALUE self, VALUE exp, VALUE mod)
{
  MP_INT *self_val, *res_val, *mod_val, *exp_val;
  VALUE res;
  int free_mod_val = 0;

  if (GMPZ_P(mod)) {
    mpz_get_struct(mod, mod_val);
    if (mpz_sgn(mod_val) <= 0) {
      rb_raise(rb_eRangeError, "modulus must be positive");
    }
  } else if (FIXNUM_P(mod)) {
    if (FIX2NUM(mod) <= 0) {
      rb_raise(rb_eRangeError, "modulus must be positive");
    }
    mpz_temp_alloc(mod_val);
    mpz_init_set_ui(mod_val, FIX2NUM(mod));
    free_mod_val = 1;
  } else if (BIGNUM_P(mod)) {
    mpz_temp_from_bignum(mod_val, mod);
    if (mpz_sgn(mod_val) <= 0) {
      mpz_temp_free(mod_val);
      rb_raise(rb_eRangeError, "modulus must be positive");
    }
    free_mod_val = 1;
  } else {
    typeerror_as(ZXB, "modulus");
  }
  mpz_make_struct_init(res, res_val);
  mpz_get_struct(self, self_val);

  if (GMPZ_P(exp)) {
    mpz_get_struct(exp, exp_val);
    if (mpz_sgn(mod_val) < 0) {
      rb_raise(rb_eRangeError, "exponent must be nonnegative");
    }
    mpz_powm(res_val, self_val, exp_val, mod_val);
  } else if (FIXNUM_P(exp)) {
    if (FIX2NUM(exp) < 0)
    {
      if (free_mod_val)
        mpz_temp_free(mod_val);
      rb_raise(rb_eRangeError, "exponent must be nonnegative");
    }
    mpz_powm_ui(res_val, self_val, FIX2NUM(exp), mod_val);
  } else if (BIGNUM_P(exp)) {
    mpz_temp_from_bignum(exp_val, exp);
    mpz_powm(res_val, self_val, exp_val, mod_val);
    mpz_temp_free(exp_val);
  } else {
    if (free_mod_val)
      mpz_temp_free(mod_val);
    typeerror_as(ZXB, "exponent");
  }
  if (free_mod_val)
    mpz_temp_free(mod_val);
  return res;
}

#probab_prime?Boolean

Number Theoretic Functions

Returns:

  • (Boolean)

#remove(f) ⇒ Object

Remove all occurrences of the factor f from n, returning the result as r. t, how many such occurrences were removed, is also returned.



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# File 'ext/gmpz.c', line 1950

VALUE r_gmpz_remove(VALUE self, VALUE arg)
{
  MP_INT *self_val, *arg_val, *res_val;
  VALUE res;
#if __GNU_MP_VERSION>2
  unsigned long removed_val;
#else
  int   removed_val;
#endif
  int free_arg_val = 0;

  mpz_get_struct(self, self_val);

  if (GMPZ_P(arg)) {
    mpz_get_struct(arg,arg_val);
    if (mpz_sgn(arg_val) != 1)
      rb_raise(rb_eRangeError, "argument must be positive");
  } else if (FIXNUM_P(arg)) {
    if (FIX2NUM(arg) <= 0)
      rb_raise(rb_eRangeError, "argument must be positive");
    mpz_temp_alloc(arg_val);
    mpz_init_set_ui(arg_val, FIX2NUM(arg));
  } else if (BIGNUM_P(arg)) {
    mpz_temp_from_bignum(arg_val, arg);
    if (mpz_sgn(arg_val) != 1) {
      mpz_temp_free(arg_val);
      rb_raise(rb_eRangeError, "argument must be positive");
    }
  } else {
    typeerror(ZXB);
  }

  mpz_make_struct_init(res, res_val);
  removed_val = mpz_remove(res_val, self_val, arg_val);

  if (free_arg_val)
    mpz_temp_free(arg_val);

  return rb_assoc_new(res, INT2FIX(removed_val));
}

#rootObject

call-seq:

a.root(b)

Returns the truncated integer part of the bth root of a.

#scan0(starting_bit) ⇒ Object

Scan a, starting from bit starting_bit, towards more significant bits, until the first 0 bit is found. Return the index of the found bit.

If the bit at starting_bit is already what’s sought, then starting_bit is returned.

If there’s no bit found, then INT2FIX(ULONG_MAX) is returned. This will happen in scan0 past the end of a negative number.



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# File 'ext/gmpz.c', line 2349

VALUE r_gmpz_scan0(VALUE self, VALUE bitnr)
{
  MP_INT *self_val;
  int bitnr_val;
  mpz_get_struct (self, self_val);
  if (FIXNUM_P (bitnr)) {
    bitnr_val = FIX2INT (bitnr);
  } else {
    typeerror_as (X, "index");
  }
  return INT2FIX (mpz_scan0 (self_val, bitnr_val));
}

#scan1(starting_bit) ⇒ Object

Scan a, starting from bit starting_bit, towards more significant bits, until the first 1 bit is found. Return the index of the found bit.

If the bit at starting_bit is already what’s sought, then starting_bit is returned.

If there’s no bit found, then INT2FIX(ULONG_MAX) is returned. This will happen in scan1 past the end of a nonnegative number.



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# File 'ext/gmpz.c', line 2375

VALUE r_gmpz_scan1(VALUE self, VALUE bitnr)
{
  MP_INT *self_val;
  int bitnr_val;

  mpz_get_struct (self, self_val);

  if (FIXNUM_P (bitnr)) {
    bitnr_val = FIX2INT (bitnr);
  } else {
    typeerror_as (X, "index");
  }

  return INT2FIX (mpz_scan1 (self_val, bitnr_val));
}

#sgnObject

Returns +1 if a > 0, 0 if a == 0, and -1 if a < 0.



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# File 'ext/gmpz.c', line 2211

VALUE r_gmpz_sgn(VALUE self)
{
  MP_INT *self_val;
  mpz_get_struct(self, self_val);
  return INT2FIX(mpz_sgn(self_val));
}

#sizeObject

Return the size of a measured in number of limbs. If a is zero, the returned value will be zero.

Since:

  • 0.4.19



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# File 'ext/gmpz.c', line 2514

VALUE r_gmpz_size(VALUE self)
{
  MP_INT *self_val;
  mpz_get_struct(self, self_val);
  return INT2FIX(mpz_size(self_val));
}

#size_in_binObject

Return the size of a measured in number of digits in binary. The sign of a is ignored, just the absolute value is used. If a is zero the return value is 1.

Since:

  • 0.2.11



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# File 'ext/gmpz.c', line 2493

VALUE r_gmpz_size_in_bin(VALUE self)
{
  MP_INT *self_val;
  mpz_get_struct (self, self_val);
  return INT2FIX (mpz_sizeinbase (self_val, 2));
}

#sizeinbaseObject Also known as: size_in_base

#sqrtObject

call-seq:

a.sqrt

Returns the truncated integer part of the square root of a.

#sqrt!Object

call-seq:

a.sqrt!

Sets a to the truncated integer part of its square root.

#sqrtremObject

#square?Boolean

call-seq:

p.square?

Returns true if p is a perfect square, i.e., if the square root of p is an integer. Under this definition both 0 and 1 are considered to be perfect squares.

Returns:

  • (Boolean)

#sub!(b) ⇒ Object

Subtracts b from a in-place, setting a to the difference. b must be an instance of one of:

  • GMP::Z

  • Fixnum

  • GMP::Q

  • GMP::F

  • Bignum



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# File 'ext/gmpz.c', line 981

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

  mpz_get_struct(self,self_val);

  if (GMPZ_P(arg)) {
    mpz_get_struct(arg, arg_val);
    mpz_sub (self_val, self_val, arg_val);
  } else if (FIXNUM_P(arg)) {
    if (FIX2NUM(arg) > 0)
      mpz_sub_ui (self_val, self_val, FIX2NUM(arg));
    else
      mpz_add_ui (self_val, self_val, -FIX2NUM(arg));
  } else if (BIGNUM_P(arg)) {
    mpz_temp_from_bignum(arg_val, arg);
    mpz_sub (self_val, self_val, arg_val);
    mpz_temp_free (arg_val);
  } else {
    typeerror (ZXB);
  }
  return Qnil;
}

#submul!(b, c) ⇒ Object

Sets a to a minus b times c. b and c must each be an instance of one of

  • GMP::Z

  • Fixnum

  • Bignum

Since:

  • 0.5.23



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# File 'ext/gmpz.c', line 1113

static VALUE r_gmpz_submul_self(VALUE self, VALUE b, VALUE c)
{
  MP_INT *self_val, *b_val, *c_val;
  int free_b_val = 0;

  if (GMPZ_P(b)) {
    mpz_get_struct(b, b_val);
  } else if (FIXNUM_P(b)) {
    mpz_temp_alloc(b_val);
    mpz_init_set_si(b_val, FIX2NUM(b));
    free_b_val = 1;
  } else if (BIGNUM_P(b)) {
    mpz_temp_from_bignum(b_val, b);
    free_b_val = 1;
  } else {
    typeerror_as(ZXB, "addend");
  }
  mpz_get_struct(self, self_val);

  if (GMPZ_P(c)) {
    mpz_get_struct(c, c_val);
    mpz_submul(self_val, b_val, c_val);
  } else if (FIXNUM_P(c)) {
    if (FIX2NUM(c) < 0)
    {
      if (free_b_val) { mpz_temp_free(b_val); }
      rb_raise(rb_eRangeError, "multiplicand (Fixnum) must be nonnegative");
    }
    mpz_submul_ui(self_val, b_val, FIX2NUM(c));
  } else if (BIGNUM_P(c)) {
    mpz_temp_from_bignum(c_val, c);
    mpz_submul(self_val, b_val, c_val);
    mpz_temp_free(c_val);
  } else {
    if (free_b_val)
      mpz_temp_free(b_val);
    typeerror_as(ZXB, "multiplicand");
  }
  if (free_b_val)
    mpz_temp_free(b_val);
  return self;
}

#swap(b) ⇒ Object

Efficiently swaps the contents of a with b. b must be an instance of GMP::Z.

Returns:

  • nil



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# File 'ext/gmpz.c', line 689

VALUE r_gmpz_swap(VALUE self, VALUE arg)
{
  MP_INT *self_val, *arg_val;
  if (!GMPZ_P(arg)) {
    rb_raise(rb_eTypeError, "Can't swap GMP::Z with object of other class");
  }
  mpz_get_struct(self, self_val);
  mpz_get_struct(arg, arg_val);
  mpz_swap(self_val,arg_val);
  return Qnil;
}

#tdivObject

call-seq:

n.tdiv(d)

Divides n by d, forming a quotient q. tdiv rounds q towards zero. The t stands for “truncate”.

q will satisfy n=q*d+r, and r will satisfy 0 <= abs( r ) < abs( d ).

This function calculates only the quotient.

#tmodObject

call-seq:

n.tmod(d)

Divides n by d, forming a remainder r. r will have the same sign as n. The t stands for “truncate”.

r will satisfy n=q*d+r, and r will satisfy 0 <= abs( r ) < abs( d ).

This function calculates only the remainder.

The remainder can be negative, so the return value is the absolute value of the remainder.

#to_dObject

TODO:

Implement mpz_fits_slong_p

Returns a as a Float if a fits in a Float.

Otherwise returns the least significant part of a, with the same sign as a.

If a is too big to fit in a Float, the returned result is probably not very useful. To find out if the value will fit, use the function mpz_fits_slong_p (Unimplemented).



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# File 'ext/gmpz.c', line 749

VALUE r_gmpz_to_d(VALUE self)
{
  MP_INT *self_val;
  mpz_get_struct(self, self_val);

  return rb_float_new(mpz_get_d(self_val));
}

#to_iObject

TODO:

Implement mpz_fits_slong_p

Returns a as an Fixnum if a fits into a Fixnum.

Otherwise returns the least significant part of a, with the same sign as a.

If a is too big to fit in a Fixnum, the returned result is probably not very useful. To find out if the value will fit, use the function mpz_fits_slong_p (Unimplemented).



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# File 'ext/gmpz.c', line 720

VALUE r_gmpz_to_i(VALUE self)
{
  MP_INT *self_val;
  char *str;
  VALUE res;

  mpz_get_struct(self, self_val);
  if (mpz_fits_slong_p(self_val))
    return rb_int2inum(mpz_get_si(self_val));
  str = mpz_get_str(NULL, 0, self_val);
  res = rb_cstr2inum(str, 10);
  free(str);
  return res;
}

#to_s(*args) ⇒ Object

call-seq:

a.to_s(base = 10)
a.to_s(:bin)
a.to_s(:oct)
a.to_s(:dec)
a.to_s(:hex)

Returns a, as a String. If base is not provided, then the decimal representation will be returned.

From the GMP Manual:

Convert a to a string of digits in base base. The base argument may vary from 2 to 62 or from -2 to -36.

For base in the range 2..36, digits and lower-case letters are used; for -2..-36, digits and upper-case letters are used; for 37..62, digits, upper-case letters, and lower-case letters (in that significance order) are used.



779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
# File 'ext/gmpz.c', line 779

VALUE r_gmpz_to_s(int argc, VALUE *argv, VALUE self)
{
  MP_INT *self_val;
  char *str;
  VALUE res;
  VALUE base;
  int base_val = 10;
  ID base_id;
  const char * bin_base = "bin";                            /* binary */
  const char * oct_base = "oct";                             /* octal */
  const char * dec_base = "dec";                           /* decimal */
  const char * hex_base = "hex";                       /* hexadecimal */
  ID bin_base_id = rb_intern(bin_base);
  ID oct_base_id = rb_intern(oct_base);
  ID dec_base_id = rb_intern(dec_base);
  ID hex_base_id = rb_intern(hex_base);

  rb_scan_args(argc, argv, "01", &base);
  if (NIL_P(base)) { base = INT2FIX(10); }           /* default value */
  if (FIXNUM_P(base)) {
    base_val = FIX2INT(base);
    if ((base_val >=   2 && base_val <= 62) ||
        (base_val >= -36 && base_val <= -2)) {
      /* good base */
    } else {
      base_val = 10;
      rb_raise(rb_eRangeError, "base must be within [2, 62] or [-36, -2].");
    }
  } else if (SYMBOL_P(base)) {
    base_id = rb_to_id(base);
    if (base_id == bin_base_id) {
      base_val =  2;
    } else if (base_id == oct_base_id) {
      base_val =  8;
    } else if (base_id == dec_base_id) {
      base_val = 10;
    } else if (base_id == hex_base_id) {
      base_val = 16;
    } else {
      base_val = 10;  /* should raise an exception here. */
    }
  }

  Data_Get_Struct(self, MP_INT, self_val);
  str = mpz_get_str(NULL, base_val, self_val);
  res = rb_str_new2(str);
  free (str);

  return res;
}

#tshrObject

call-seq:

n.tshr(d)

Divides n by 2^d, forming a quotient q. tshr rounds q towards zero. The t stands for “truncate”.

q will satisfy n=q*d+r, and r will satisfy 0 <= abs( r ) < abs( d ).

This function calculates only the quotient.

#|Object

call-seq:

a | b

Returns a bitwise inclusive-or b. b must be an instance of one of the following:

  • GMP::Z

  • Fixnum

  • Bignum