add()

ring_elem SchurRing2::add ( const ring_elem f, const ring_elem g ) const

virtual

Implements Ring.

Definition at line 530 of file schur2.cpp.

{
  if (is_zero(f)) return g;
  if (is_zero(g)) return f;
  const schur_poly *f1 = f.get_schur_poly();
  const schur_poly *g1 = g.get_schur_poly();
 
  schur_poly *result = new schur_poly;
 
  schur_poly::iterator i = f1->begin();
  schur_poly::iterator j = g1->begin();
  schur_poly::iterator iend = f1->end();
  schur_poly::iterator jend = g1->end();
 
  bool done = false;
  while (!done)
    {
      int cmp = compare_partitions(i.getMonomial(), j.getMonomial());
      switch (cmp)
        {
          case LT:
            result->appendTerm(j.getCoefficient(), j.getMonomial());
            ++j;
            if (j == jend)
              {
                result->append(i, iend);
                done = true;
              }
            break;
          case GT:
            result->appendTerm(i.getCoefficient(), i.getMonomial());
            ++i;
            if (i == iend)
              {
                result->append(j, jend);
                done = true;
              }
            break;
          case EQ:
            ring_elem c =
                coefficientRing->add(i.getCoefficient(), j.getCoefficient());
            if (!coefficientRing->is_zero(c))
              result->appendTerm(c, i.getMonomial());
            ++j;
            ++i;
            if (j == jend)
              {
                result->append(i, iend);
                done = true;
              }
            else
              {
                if (i == iend)
                  {
                    result->append(j, jend);
                    done = true;
                  }
              }
            break;
        }
    }
  return ring_elem(result);
}

References schur_poly::begin(), coefficientRing, compare_partitions(), schur_poly::end(), EQ, ring_elem::get_schur_poly(), schur_poly_iterator::getCoefficient(), schur_poly_iterator::getMonomial(), GT, is_zero(), LT, and result().

Referenced by subtract().