to_M2_MutableMatrix() [2/2]

MutableMatrix * ResF4toM2Interface::to_M2_MutableMatrix ( SchreyerFrame & C, const Ring * R, int lev )

static

Definition at line 242 of file res-f4-m2-interface.cpp.

{
  // Ring will be R, which should be a polynomial ring with the same monoid as
  // ring of C.
  const PolynomialRing* RP = R->cast_to_PolynomialRing();
  const Monoid* M = RP->getMonoid();
 
  if (lev <= 0 or lev > C.maxLevel())
    {
      return MutableMatrix::zero_matrix(
          R,
          0,  // TODO: set this correctly?
          0,  // TODO: set this correctly?  i.e. one of these might be in range,
          // so getting the rank correct might be good.
          true);
    }
 
  auto& thislevel = C.level(lev);
  int ncols = static_cast<int>(thislevel.size());
  int nrows = static_cast<int>(C.level(lev - 1).size());
 
  // create the mutable matrix
  MutableMatrix* result = MutableMatrix::zero_matrix(R, nrows, ncols, true);
 
  //  Nterm **comps = newarray(Nterm *, nrows);
  Nterm** comps = newarray(Nterm*, nrows);
  Nterm** last = newarray(Nterm*, nrows);
 
  monomial m1 = M->make_one();
  // FIXME: is exp a monomial or exponent vector?
  int* exp = new int[M->n_vars() + 1];
 
  int j = 0;
  for (auto j1 = thislevel.cbegin(); j1 != thislevel.cend(); ++j1, ++j)
    {
      // Now we create the polynomials for column j
      // into 'comps', 'last'.
      const ResPolynomial& f = (*j1).mSyzygy;
      for (int i = 0; i < nrows; i++)
        {
          comps[i] = nullptr;
          last[i] = nullptr;  // used to easily place monomials in the correct
                              // bin, at the end of the polynomials.
        }
      const res_monomial_word* w = f.monoms.data();
      for (int i = 0; i < f.len; i++)
        {
          component_index comp;
          C.ring().monoid().to_expvector(w, exp, comp);
          w = w + C.ring().monoid().monomial_size(w);
          M->from_expvector(exp, m1);
      ring_elem a = C.vectorArithmetic().ringElemFromElementArray(f.coeffs, i);
          Nterm* g = RP->make_flat_term(a, m1);
          if (g == nullptr) continue;
          g->next = nullptr;
          if (last[comp] == nullptr)
            {
              comps[comp] = g;
              last[comp] = g;
            }
          else
            {
              last[comp]->next = g;
              last[comp] = g;
            }
        }
      // Now we have run through the entire vector, so put it into result
      for (int r = 0; r < nrows; r++) result->set_entry(r, j, comps[r]);
    }
 
  delete[] exp;
  freemem(comps);
  freemem(last);
  return result;
}

References Ring::cast_to_PolynomialRing(), ResPolynomial::coeffs, freemem(), Monoid::from_expvector(), PolynomialRing::getMonoid(), ResPolynomial::len, SchreyerFrame::level(), PolynomialRing::make_flat_term(), Monoid::make_one(), SchreyerFrame::maxLevel(), ResPolyRing::monoid(), monomial, ResMonoidDense::monomial_size(), ResPolynomial::monoms, Monoid::n_vars(), newarray, Nterm::next, result(), SchreyerFrame::ring(), VectorArithmetic::ringElemFromElementArray(), ResMonoidDense::to_expvector(), SchreyerFrame::vectorArithmetic(), and MutableMatrix::zero_matrix().

Referenced by F4ResComputation::get_matrix(), F4ResComputation::get_mutable_matrix(), and F4ResComputation::get_mutable_matrix().