rawNonTermOrderVariables()

M2_arrayint rawNonTermOrderVariables

(

const MonomialOrdering *

mo

)

Definition at line 466 of file monomial-ordering.cpp.

{
  int i, j, sum, nextvar;
  int nvars = rawNumberOfVariables(mo);
  int *gt = getmematomicvectortype(int, nvars);
  for (i = 0; i < nvars; i++)
    gt[i] =
        0;  // 0 means undecided, -1 means non term order, 1 means term order
  // Now we loop through the parts of the monomial order
  nextvar = 0;
  for (i = 0; i < mo->len; i++)
    {
      mon_part p = mo->array[i];
      switch (p->type)
        {
          case MO_LEX:
          case MO_LEX2:
          case MO_LEX4:
          case MO_GREVLEX:
          case MO_GREVLEX2:
          case MO_GREVLEX4:
          case MO_GREVLEX_WTS:
          case MO_GREVLEX2_WTS:
          case MO_GREVLEX4_WTS:
          case MO_LAURENT:
          case MO_NC_LEX:
            for (j = 0; j < p->nvars; j++, nextvar++)
              if (gt[nextvar] == 0) gt[nextvar] = 1;
            break;
          case MO_LAURENT_REVLEX:
          case MO_REVLEX:
            for (j = 0; j < p->nvars; j++, nextvar++)
              if (gt[nextvar] == 0) gt[nextvar] = -1;
            break;
          case MO_WEIGHTS:
            for (j = nextvar; j < p->nvars; j++)
              if (gt[j] == 0)
                {
                  if (p->wts[j] > 0)
                    gt[j] = 1;
                  else if (p->wts[j] < 0)
                    gt[j] = -1;
                }
            break;
          case MO_POSITION_UP:
          case MO_POSITION_DOWN:
            break;
        }
    }
  // At this point every variables' gt should be 1 or -1.
  sum = 0;
  for (i = 0; i < nvars; i++)
    {
      if (gt[i] == 0) INTERNAL_ERROR("gt[i] should not be 0");
      if (gt[i] < 0) sum++;
    }
 
  // Make an array of this length.
  M2_arrayint result = M2_makearrayint(sum);
  nextvar = 0;
  for (i = 0; i < nvars; i++)
    if (gt[i] < 0) result->array[nextvar++] = i;
  return result;
}

References MonomialOrdering::array, getmematomicvectortype, INTERNAL_ERROR(), MonomialOrdering::len, M2_makearrayint(), MO_GREVLEX, MO_GREVLEX2, MO_GREVLEX2_WTS, MO_GREVLEX4, MO_GREVLEX4_WTS, MO_GREVLEX_WTS, MO_LAURENT, MO_LAURENT_REVLEX, MO_LEX, MO_LEX2, MO_LEX4, MO_NC_LEX, MO_POSITION_DOWN, MO_POSITION_UP, MO_REVLEX, MO_WEIGHTS, mon_part::nvars, p, rawNumberOfVariables(), and result().