Function sparseHeuristic

factory/facSparseHensel.cc:159–412

}

CFList
sparseHeuristic (const CanonicalForm& A, const CFList& biFactors,
                 CFList*& moreBiFactors, const CFList& evaluation,
                 int minFactorsLength)
{
  int j= A.level() - 1;
  int i;

  //initialize storage
  CFArray *** storeFactors= new CFArray** [j];
  for (i= 0; i < j; i++)
    storeFactors [i]= new CFArray* [2];

  CFArray eval= CFArray (j);
  i= j - 1;
  for (CFListIterator iter= evaluation; iter.hasItem(); iter++,i--)
    eval[i]= iter.getItem();
  storeFactors [0] [0]= new CFArray [minFactorsLength];
  storeFactors [0] [1]= new CFArray [minFactorsLength];
  for (i= 1; i < j; i++)
  {
    storeFactors[i] [0]= new CFArray [minFactorsLength];
    storeFactors[i] [1]= new CFArray [minFactorsLength];
  }
  //

  CFList * normalizingFactors= new CFList [j];
  CFList uniFactors;
  normalizingFactors [0]= findNormalizingFactor1 (biFactors,
                                              evaluation.getLast(), uniFactors);
  for (i= j - 1; i > 0; i--)
  {
    if (moreBiFactors[i-1].length() != minFactorsLength)
    {
      moreBiFactors[i-1]=
        recombination (moreBiFactors [i-1], uniFactors, 1,
                       moreBiFactors[i-1].length()-uniFactors.length()+1,
                       eval[i], Variable (i + 2)
                      );
    }
    normalizingFactors [i]= findNormalizingFactor2 (moreBiFactors [i - 1],
                                                    eval[i], uniFactors);
  }

  CFList tmp;
  tmp= normalize (biFactors, normalizingFactors[0]);
  getTerms2 (tmp, storeFactors [0] [0]);
  storeFactors [0] [1]= evaluate (storeFactors [0] [0], minFactorsLength,
                                  evaluation.getLast(), Variable (2));
  for (i= j - 1; i > 0; i--)
  {
    tmp= normalize (moreBiFactors [i-1], normalizingFactors [i]);
    getTerms2 (tmp, storeFactors [i] [0]);
    storeFactors [i] [1]= evaluate (storeFactors [i] [0], minFactorsLength,
                                    eval[i], Variable (i + 2));
  }