IM2_Matrix_get_entries()

engine_RawRingElementArrayArrayOrNull IM2_Matrix_get_entries

(

const Matrix *

M

)

Definition at line 85 of file matrix.cpp.

{
  try
    {
      int ncols = M->n_cols();
      int nrows = M->n_rows();
      if(nrows < 0 || ncols < 0)
        {
          ERROR("internal error: matrix has a negative size %d by %d",
                nrows,
                ncols);
          return nullptr;
        }
      engine_RawRingElementArrayArray entries =
          getmemarraytype(engine_RawRingElementArrayArray, nrows);
      entries->len = nrows;
      RingElement *zero =
          RingElement::make_raw(M->get_ring(), M->get_ring()->zero());
      for(int r = 0; r < nrows; r++)
        {
          engine_RawRingElementArray currRow =
              getmemarraytype(engine_RawRingElementArray, ncols);
          currRow->len = ncols;
          std::fill_n(currRow->array, ncols, zero);
          entries->array[r] = currRow;
        }
      //walk through the columns
      for(int c = 0; c < ncols; c++)
        {
          const vec &column = M->elem(c);
          for(const vecterm &term : column)
            {
              if(term.comp < 0 || term.comp >= nrows)
                {
                  ERROR("internal error: matrix contains invalid entries:"
                        "row index %d out of range 0 .. %d",
                        term.comp,
                        nrows - 1);
                  //Ignoring the entry and continuing
                  continue;
                }
              entries->array[term.comp]->array[c] =
                  RingElement::make_raw(M->get_ring(), term.coeff);
            }
        }
      return entries;
    } catch (const exc::engine_error &e)
    {
      ERROR(e.what());
      return nullptr;
    }
  return nullptr;
}

References Matrix::elem(), ERROR, Matrix::get_ring(), getmemarraytype, RingElement::make_raw(), Matrix, Matrix::n_cols(), Matrix::n_rows(), Ring::zero(), and zero.