vec_row_op()

template<typename CoeffRing>

void SMat< CoeffRing >::vec_row_op ( sparsevec *& v, size_t r1, const elem & a, size_t r2 ) const

private

Definition at line 614 of file smat.hpp.

{
  sparsevec *p;
  sparsevec *vec2 = 0;
  for (p = v; p != 0; p = p->next)
    if (p->row == r2)
      {
        vec2 = p;
        break;
      }
  if (vec2 == 0) return;
  typename CoeffRing::Element c(ring());
  ring().set_zero(c);
  ring().mult(c, vec2->coeff, a);
  if (ring().is_zero(c))
    {
      return;  // nothing to change
    }
  // Now add c to the r1'th row of v
  sparsevec head;
  head.next = v;
  for (p = &head; p->next != 0; p = p->next)
    if (p->next->row <= r1) break;
  if (p->next == 0 || p->next->row < r1)
    {
      // Make a new node
      sparsevec *w = vec_new();
      w->next = p->next;
      w->row = r1;
      ring().init_set(w->coeff, c);
      p->next = w;
    }
  else
    {
      ring().add(p->next->coeff, p->next->coeff, c);
      if (ring().is_zero(p->next->coeff))
        {
          sparsevec *tmp = p->next;
          p->next = tmp->next;
          vec_remove_node(tmp);
        }
    }
  v = head.next;
}

References SMat< ACoeffRing >::sparsevec::coeff, is_zero(), SMat< ACoeffRing >::sparsevec::next, p, ring(), SMat< ACoeffRing >::sparsevec::row, vec_new(), and vec_remove_node().

Referenced by row_op().