diff_coefficients()

ring_elem WeylAlgebra::diff_coefficients ( const ring_elem c, const int * derivatives, const_exponents exp ) const

protected

Definition at line 307 of file weylalg.cpp.

{
  ring_elem result = K_->copy(c);
  for (int i = 0; i < _nderivatives; i++)
    {
      if (derivatives[i] == 0) continue;
      if (exp[i] <= diffcoeffstop)
        {
          ring_elem g =
              K_->from_long(diffcoeffstable[exp[i]][derivatives[i]]);
          ring_elem h = K_->mult(result, g);
          K_->remove(g);
          K_->remove(result);
          result = h;
          if (K_->is_zero(result)) return result;
        }
      else
        for (int j = derivatives[i] - 1; j >= 0; j--)
          {
            ring_elem g = K_->from_long(exp[i] - j);
            ring_elem h = K_->mult(result, g);
            K_->remove(g);
            K_->remove(result);
            result = h;
            if (K_->is_zero(result)) return result;
          }
    }
  return result;
}

References _nderivatives, diffcoeffstable, diffcoeffstop, PolynomialRing::K_, and result().

Referenced by gbvector_weyl_diff(), and weyl_diff().