tutorial/FilteredCBC.cc

This example shows how to transform, using filters, a sequence of merit values based on a component-by-component sequence of lattice definitions.

// This file is part of LatNet Builder.
//
// Copyright (C) 2012-2018  Pierre L'Ecuyer and Universite de Montreal
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "latbuilder/CoordUniformFigureOfMerit.h"
#include "latticetester/ProductWeights.h"
#include "latbuilder/Kernel/PAlpha.h"
#include "latbuilder/Kernel/PAlphaPLR.h"
#include "latbuilder/Accumulator.h"
#include "latbuilder/Functor/binary.h"
#include "latbuilder/Storage.h"

#include "latbuilder/MeritFilterList.h"
#include "latbuilder/MeritCombiner.h"
#include "latbuilder/MeritFilter.h"
#include "latbuilder/Norm/Normalizer.h"
#include "latbuilder/Norm/PAlphaSL10.h"
#include "latbuilder/Functor/LowPass.h"

#include "latbuilder/MeritSeq/CoordUniformCBC.h"
#include "latbuilder/MeritSeq/CoordUniformInnerProd.h"
#include "latbuilder/GenSeq/GeneratingValues.h"
#include "latbuilder/GenSeq/Creator.h"

#include "latbuilder/TextStream.h"

#include "Path.h"

#include <iostream>
#include <limits>

using namespace LatBuilder;
using TextStream::operator<<;

template <typename T, typename... ARGS>
std::unique_ptr<T> unique(ARGS&&... args)
{ return std::unique_ptr<T>(new T(std::forward<ARGS>(args)...)); }

template <LatticeType LA, class NORMALIZER>
void setLevelWeights(NORMALIZER&, const SizeParam<LA, EmbeddingType::UNILEVEL>&)
{}

template <LatticeType LA, class NORMALIZER>
void setLevelWeights(NORMALIZER& normalizer, const SizeParam<LA, EmbeddingType::MULTILEVEL>& sizeParam)
{
   normalizer.setWeights(RealVector(
            sizeParam.maxLevel() + 1,
            1.0 / sizeParam.maxLevel()
            ));
}

template<LatticeType LA>
void setCombiner(MeritFilterList<LA, EmbeddingType::UNILEVEL>&) {}

template<LatticeType LA>
void setCombiner(MeritFilterList<LA, EmbeddingType::MULTILEVEL>& filters)
{ filters.add(unique<MeritCombiner::Accumulator<LA, Functor::Sum>>()); }

template <LatticeType LA, EmbeddingType L, Compress C>
void test(const Storage<LA, L, C>& storage, Dimension dimension)
{  

   auto weights = unique<LatticeTester::ProductWeights>();
   weights->setDefaultWeight(0.7);

   CoordUniformFigureOfMerit<Kernel::PAlpha> figure(std::move(weights), 2);
   std::cout << "figure of merit: " << figure << std::endl;
   
   /*
   // The P_{\alpha,PLR} figure of merit for polynomial lattices
   auto weights = unique<LatticeTester::ProductWeights>();
   weights->setDefaultWeight(0.7);

   CoordUniformFigureOfMerit<Kernel::PAlphaPLR> figure(std::move(weights), 2);
   std::cout << "figure of merit: " << figure << std::endl;
   */

   typedef GenSeq::GeneratingValues<LA, decltype(figure)::suggestedCompression()> Coprime;
   auto genSeq  = GenSeq::Creator<Coprime>::create(storage.sizeParam());
   auto genSeq0 = GenSeq::Creator<Coprime>::create(SizeParam<LA, L>(LatticeTraits<LA>::TrivialModulus));

   auto cbc = MeritSeq::cbc<MeritSeq::CoordUniformInnerProd>(storage, figure);

   MeritFilterList<LA, L> filters;

   setCombiner(filters);

   auto normalizer = unique<Norm::Normalizer<LA, L, Norm::PAlphaSL10>>(
         Norm::PAlphaSL10(figure.kernel().alpha(), figure.weights())
         );
   setLevelWeights(*normalizer, storage.sizeParam());
   filters.add(std::move(normalizer));

   auto lowPass = unique<MeritFilter<LA, L>>(Functor::LowPass<Real>(1.0), "low-pass");
   filters.add(std::move(lowPass));
   std::cout << "filters: " << filters << std::endl;

   while (cbc.baseLat().dimension() < dimension) {

      Dimension baseDim = cbc.baseLat().dimension();

      std::cout << "CBC search for dimension: " << (baseDim + 1) << std::endl;
      std::cout << "base lattice: " << std::endl << cbc.baseLat();
      std::cout << "base merit value: " << cbc.baseMerit() << std::endl;

      auto meritSeq = cbc.meritSeq(baseDim == 0 ? genSeq0 : genSeq);

      auto filteredSeq = filters.apply(meritSeq);

      auto best = std::min_element(filteredSeq.begin(), filteredSeq.end());
      cbc.select(best.base());

      std::cout << "BEST LATTICE: " << std::endl << cbc.baseLat() << "Merit value: " << *best << std::endl;
   }
}

int main()
{
   SET_PATH_TO_LATNETBUILDER_FOR_EXAMPLES();
   Dimension dim = 3;
   
   test(Storage<LatticeType::ORDINARY, EmbeddingType::UNILEVEL, Compress::SYMMETRIC>(256), dim);
   test(Storage<LatticeType::ORDINARY, EmbeddingType::MULTILEVEL, Compress::SYMMETRIC>(256), dim);
   
   /*
   test(Storage<LatticeType::POLYNOMIAL, EmbeddingType::UNILEVEL, Compress::NONE>(PolynomialFromInt(115)), dim);
   test(Storage<LatticeType::POLYNOMIAL, EmbeddingType::MULTILEVEL, Compress::NONE>(PolynomialFromInt(115)), dim);
   */

   return 0;
}