Function scComputeHC

kernel/combinatorics/hdegree.cc:1074–1138

}

void scComputeHC(ideal S, ideal Q, int ak, poly &hEdge)
{
  id_LmTest(S, currRing);
  if (Q!=NULL) id_LmTest(Q, currRing);

  int  i;
  int  k = ak;
  if (rField_is_Ring(currRing) && (currRing->OrdSgn == -1))
  {
    //consider just monic generators (over rings with zero-divisors)
    ideal SS=id_Head(S,currRing);
    for(i=0;i<=idElem(S);i++)
    {
      if((SS->m[i]!=NULL)
      && ((p_IsPurePower(SS->m[i],currRing)==0)
        ||(!n_IsUnit(pGetCoeff(SS->m[i]), currRing->cf))))
      {
        p_Delete(&SS->m[i],currRing);
      }
    }
    S=id_Copy(SS,currRing);
    idSkipZeroes(S);
  }
  #if 0
  printf("\nThis is HC:\n");
  for(int ii=0;ii<=idElem(S);ii++)
  {
    pWrite(S->m[ii]);
  }
  //getchar();
  #endif
  if(idElem(S) == 0)
    return;
  hNvar = (currRing->N);
  hexist = hInit(S, Q, &hNexist);
  if (k!=0)
    hComp(hexist, hNexist, k, hexist, &hNstc);
  else
    hNstc = hNexist;
  assume(hNexist > 0);
  hwork = (scfmon)omAlloc(hNexist * sizeof(scmon));
  hvar = (varset)omAlloc((hNvar + 1) * sizeof(int));
  hpure = (scmon)omAlloc((1 + (hNvar * hNvar)) * sizeof(int));
  stcmem = hCreate(hNvar - 1);
  for (i = hNvar; i>0; i--)
    hvar[i] = i;
  hStaircase(hexist, &hNstc, hvar, hNvar);
  if ((hNvar > 2) && (hNstc > 10))
    hOrdSupp(hexist, hNstc, hvar, hNvar);
  memset(hpure, 0, (hNvar + 1) * sizeof(int));
  hPure(hexist, 0, &hNstc, hvar, hNvar, hpure, &hNpure);
  hLexS(hexist, hNstc, hvar, hNvar);
  if (hEdge!=NULL)
    pLmFree(hEdge);
  hEdge = pInit();
  pWork = pInit();
  hHedgeStep(hpure, hexist, hNstc, hvar, hNvar,hEdge);
  pSetComp(hEdge,ak);