gbvector_parallel_lead_terms()

gbvector * GBRing::gbvector_parallel_lead_terms	(	M2_arrayint	w,
		const FreeModule *	F,
		const gbvector *	leadv,
		const gbvector *	v )

Definition at line 495 of file gbring.cpp.

{
  (void) F;
  if (v == nullptr) return nullptr;
 
  // loop through every term of v.  Keep those t that satisfy: exp(leadv) -
  // exp(t)
  // is a multiple of w
  //
 
  exponents_t lead = ALLOCATE_EXPONENTS(exp_size);
  exponents_t e = ALLOCATE_EXPONENTS(exp_size);
 
  M->to_expvector(leadv->monom, lead);
 
  gbvector head;
  gbvector *result = &head;
  for (const gbvector *t = v; t != nullptr; t = t->next)
    {
      M->to_expvector(t->monom, e);
      if (leadv == t || isparallel(w, lead, e))
        {
          result->next = gbvector_copy_term(t);
          result = result->next;
        }
    }
  result->next = nullptr;
  return head.next;
}

References ALLOCATE_EXPONENTS, exp_size, gbvector_copy_term(), isparallel(), M, gbvector::monom, gbvector::next, and result().