DetComputation()

DetComputation::DetComputation	(	const Matrix *	M,
		int	p,
		bool	do_exterior,
		int	strategy )

Definition at line 8 of file det.cpp.

    : R(M0->get_ring()),
      M(M0),
      done(false),
      p(p0),
      do_exterior(do_exterior0),
      strategy(strategy0),
      row_set(nullptr),
      col_set(nullptr),
      this_row(0),
      this_col(0),
      D(nullptr),
      dynamic_cache(0)
{
  if (do_exterior)
    {
      F = M->rows()->exterior(p);
      FreeModule *G = M->cols()->exterior(p);
      int *deg = R->degree_monoid()->make_new(M->degree_shift());
      R->degree_monoid()->power(deg, p, deg);
      result = MatrixConstructor(F, G, deg);
      R->degree_monoid()->remove(deg);
    }
  else
    {
      F = R->make_FreeModule(1);
      result = MatrixConstructor(F, 0);
    }
 
  // Handle trivial cases
  if (p < 0)
    {
      // In either case, want a zero matrix
      done = true;
      return;
    }
  if (p == 0)
    {
      // We want a single element which is '1'
      if (do_exterior)
        result.set_entry(0, 0, R->one());
      else
        result.append(R->make_vec(0, R->one()));
      done = true;
      return;
    }
  if (p > M->n_rows() || p > M->n_cols())
    {
      // Zero matrix in either case
      done = true;
      return;
    }
  done = false;
 
  row_set = newarray_atomic(size_t, p);
  col_set = newarray_atomic(size_t, p);
 
  for (size_t i = 0; i < p; i++)
    {
      row_set[i] = i;
      col_set[i] = i;
    }
 
  D = newarray(ring_elem *, p);
  for (size_t i = 0; i < p; i++)
    {
      D[i] = newarray(ring_elem, p);
      for (size_t j = 0; j < p; j++) D[i][j] = ZERO_RINGELEM;
    }
}

References col_set, D, do_exterior, done, dynamic_cache, F, G, M, Matrix, newarray, newarray_atomic, p, R, result, row_set, strategy, this_col, this_row, and ZERO_RINGELEM.