Lattice Builder Manual
Software Package for Constructing Rank-1 Lattices
tutorial/FilteredRCBC.cc

This example shows how to use signals to control the number of elements from a random lattice sequence to be examined by a minimization algorithm, and thus ignore candidate lattices rejected by filters.

// Copyright (c) 2012, 2013 David Munger, Pierre L'Ecuyer, Université de Montréal.
//
// This file is part of Lattice Builder.
//
// Lattice Builder is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Lattice Builder is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Lattice Builder. If not, see <http://www.gnu.org/licenses/>.
#include "latbuilder/CoordUniformFigureOfMerit.h"
#include "latcommon/ProductWeights.h"
#include "latbuilder/Kernel/PAlpha.h"
#include "latbuilder/Accumulator.h"
#include "latbuilder/Storage.h"
#include "latbuilder/MeritFilterList.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/CoprimeIntegers.h"
#include "latbuilder/GenSeq/Creator.h"
#include "latbuilder/Traversal.h"
#include "latbuilder/LFSR113.h"
#include "latbuilder/Functor/MinElement.h"
#include "latbuilder/TextStream.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 <LatType LAT>
class Observer {
public:
Observer(int maxCount) { m_maxCount = maxCount; m_count = m_totalCount = 0; }
void onStart() { m_count = m_totalCount = 0; }
bool onElementVisited(const Real&) { ++m_totalCount; return ++m_count < m_maxCount; }
void onReject(const LatDef&) { m_count--; }
int count() const { return m_count; }
int totalCount() const { return m_totalCount; }
private:
int m_maxCount;
int m_count;
int m_totalCount;
};
template <LatType L, Compress C>
void test(const Storage<L, C>& storage, Dimension dimension, int samples)
{
auto weights = unique<LatCommon::ProductWeights>();
weights->setDefaultWeight(0.7);
CoordUniformFigureOfMerit<Kernel::PAlpha> figure(std::move(weights), 2);
std::cout << "figure of merit: " << figure << std::endl;
auto genSeq = GenSeq::Creator<Coprime>::create(storage.sizeParam());
auto cbc = MeritSeq::cbc<MeritSeq::CoordUniformInnerProd>(storage, figure);
auto normalizer = unique<Norm::Normalizer<L, Norm::PAlphaSL10>>(
Norm::PAlphaSL10(figure.kernel().alpha(), figure.weights())
);
filters.add(std::move(normalizer));
auto lowPass = unique<MeritFilter<L>>(Functor::LowPass<Real>(1.0), "low-pass");
filters.add(std::move(lowPass));
std::cout << "filters: " << filters << std::endl;
Observer<L> obs(samples);
minElement.onStart().connect(boost::bind(&Observer<L>::onStart, &obs));
minElement.onElementVisited().connect(boost::bind(&Observer<L>::onElementVisited, &obs, _1));
filters.template onReject<L>().connect(boost::bind(&Observer<L>::onReject, &obs, _1));
while (cbc.baseLat().dimension() < dimension) {
Dimension baseDim = cbc.baseLat().dimension();
std::cout << "CBC search for dimension: " << (baseDim + 1) << std::endl;
std::cout << " base lattice: " << cbc.baseLat() << std::endl;
std::cout << " base merit value: " << cbc.baseMerit() << std::endl;
auto meritSeq = cbc.meritSeq(baseDim == 0 ? genSeq0 : genSeq);
auto filteredSeq = filters.apply(meritSeq);
auto best = minElement(filteredSeq.begin(), filteredSeq.end());
cbc.select(best.base());
std::cout << "BEST LATTICE: " << cbc.baseLat() << " with merit value " << *best << std::endl;
std::cout << " " << obs.count() << " accepted / " << obs.totalCount() << " tried" << std::endl;;
// use a different permutation for the next iteration
genSeq.randomGenerator().jump();
}
}
int main()
{
Dimension dim = 3;
int samples = 15;
return 0;
}