row_permute()

template<typename CoeffRing>

bool SMat< CoeffRing >::row_permute	(	size_t	start_row,
		M2_arrayint	perm )

Definition at line 1010 of file smat.hpp.

{
  // We copy one row to another location for each cycle in 'perm' of length > 1.
  size_t nrows_to_permute = perm->len;
  bool *done = newarray_atomic(bool, nrows_to_permute);
  for (size_t i = 0; i < nrows_to_permute; i++) done[i] = true;
  for (size_t i = 0; i < nrows_to_permute; i++)
    {
      size_t j = perm->array[i];
      if (!done[j])
        {
          ERROR("expected permutation");
          freemem(done);
          return false;
        }
      done[j] = false;
    }
  for (size_t c = 0; c < ncols_; c++) vec_permute(columns_[c], start_row, perm);
  return true;
}

References columns_, ERROR, freemem(), ncols_, newarray_atomic, and vec_permute().

Referenced by MatElementaryOps< SMat< RT > >::row_permute().