power() [2/2]

ring_elem FractionField::power ( const ring_elem f, mpz_srcptr n ) const

virtual

Exponentiation. This is the default function, if a class doesn't define this.

Reimplemented from Ring.

Definition at line 549 of file frac.cpp.

{
  frac_elem *f = FRAC_VAL(a);
  ring_elem top, bottom;
  if (mpz_sgn(n) >= 0)
    {
      top = R_->power(f->numer, n);
      bottom = R_->power(f->denom, n);
 
      if (R_->is_zero(bottom)) return set_non_unit_frac(f->denom);
    }
  else
    {
      if (R_->is_zero(f->numer))
        {
          throw exc::division_by_zero_error();
        }
      mpz_t abs_n;
      mpz_init(abs_n);
      mpz_abs(abs_n, n);
 
      top = R_->power(f->denom, abs_n);
      bottom = R_->power(f->numer, abs_n);
 
      mpz_clear(abs_n);
      
      if (R_->is_zero(bottom)) return set_non_unit_frac(f->numer);
    }
 
  return FRAC_RINGELEM(make_elem(top, bottom));
}

References frac_elem::denom, FRAC_RINGELEM, FRAC_VAL, make_elem(), frac_elem::numer, R_, and set_non_unit_frac().