DiscreteExteriorCalculusFactory.ih

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 *  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.
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/**
 * @file DiscreteExteriorCalculusFactory.ih
 * @author Pierre Gueth (\c pierre.gueth@liris.cnrs.fr )
 * Laboratoire d'InfoRmatique en Image et Systemes d'information - LIRIS (CNRS, UMR 5205), CNRS, France
 *
 * @date 2015/05/04
 *
 * Implementation of inline methods for DiscreteExteriorCalculusFactory
 *
 * This file is part of the DGtal library.
 */
 
///////////////////////////////////////////////////////////////////////////////
// Implementation of inline methods                                          //
 
template <typename TLinearAlgebraBackend, typename TInteger>
template <typename TDigitalSet>
DGtal::DiscreteExteriorCalculus<TDigitalSet::Point::dimension, TDigitalSet::Point::dimension, TLinearAlgebraBackend, TInteger>
DGtal::DiscreteExteriorCalculusFactory<TLinearAlgebraBackend, TInteger>::createFromDigitalSet(const TDigitalSet& _set, const bool add_border)
{
    BOOST_CONCEPT_ASSERT(( DGtal::concepts::CDigitalSet<TDigitalSet> ));
 
    typedef DGtal::DiscreteExteriorCalculus<TDigitalSet::Point::dimension, TDigitalSet::Point::dimension, TLinearAlgebraBackend, TInteger> Calculus;
    typedef typename Calculus::Cell Cell;
    typedef typename Calculus::Scalar Scalar;
    typedef typename Calculus::Index Index;
    typedef typename Calculus::Point Point;
    typedef typename Calculus::Property Property;
 
    Calculus calculus;
    calculus.template initKSpace<typename TDigitalSet::Domain>(_set.domain());
 
    // compute raw cell size
    typedef std::map<Cell, Scalar> Accum;
    Accum cell_size_accum;
    for (typename TDigitalSet::ConstIterator ri=_set.begin(), rie=_set.end(); ri!=rie; ri++)
    {
        const Point& point = *ri;
        const Cell cell_point = calculus.myKSpace.uSpel(point);
 
        typedef DGtal::SpaceND<Calculus::dimensionAmbient, TInteger> Space;
        typedef DGtal::HyperRectDomain<Space> Neighborbood;
        const Point cell_coords = calculus.myKSpace.uKCoords(cell_point);
        const Neighborbood neighborhood(cell_coords-Point::diagonal(1), cell_coords+Point::diagonal(1));
        for (typename Neighborbood::ConstIterator pi=neighborhood.begin(), pie=neighborhood.end(); pi!=pie; pi++)
        {
            const Cell cell = calculus.myKSpace.uCell(*pi);
            if (cell_size_accum.find(cell) == cell_size_accum.end()) cell_size_accum[cell] = 0;
            cell_size_accum[cell] += 1;
        }
    }
 
    // normalize cell size and set flipped flag
    for (typename Accum::const_iterator csi=cell_size_accum.begin(), csie=cell_size_accum.end(); csie!=csi; csi++)
    {
        const Cell& cell = csi->first;
        const DGtal::Dimension dual_dim = Calculus::dimensionEmbedded-calculus.myKSpace.uDim(cell);
        const Scalar factor = pow(.5, dual_dim);
 
        const Scalar normalized_size = csi->second * factor;
        ASSERT(normalized_size > 0 && normalized_size <= 1);
 
        if (!add_border && normalized_size < 1) continue;
 
        Property property;
        property.primal_size = 1;
        property.dual_size = normalized_size;
        property.index = std::numeric_limits<Index>::max();
        property.flipped = false;
 
        calculus.myCellProperties[cell] = property;
    }
 
    calculus.myIndexesNeedUpdate = true;
    calculus.updateIndexes();
 
    return calculus;
}
 
template <typename TLinearAlgebraBackend, typename TInteger>
template <typename KSpace, typename CellsSet>
void
DGtal::DiscreteExteriorCalculusFactory<TLinearAlgebraBackend, TInteger>::insertAllLowerIncidentCells(const KSpace& kspace, const typename CellsSet::value_type& cell, CellsSet& cells_set)
{
    typedef typename KSpace::Cells Cells;
 
    cells_set.insert(cell);
 
    const Cells border = kspace.uLowerIncident(cell);
    for (typename Cells::ConstIterator bi=border.begin(), be=border.end(); bi!=be; bi++)
        insertAllLowerIncidentCells(kspace, *bi, cells_set);
}
 
template <typename TLinearAlgebraBackend, typename TInteger>
template <typename KSpace, typename CellsAccum>
void
DGtal::DiscreteExteriorCalculusFactory<TLinearAlgebraBackend, TInteger>::accumulateAllLowerIncidentCells(const KSpace& kspace, const typename CellsAccum::key_type& cell, CellsAccum& cells_accum)
{
    typedef typename KSpace::Cells Cells;
 
    if (cells_accum.find(cell) == cells_accum.end()) cells_accum[cell] = 0;
    cells_accum[cell]++;
 
    const Cells border = kspace.uLowerIncident(cell);
    for (typename Cells::ConstIterator bi=border.begin(), be=border.end(); bi!=be; bi++)
        accumulateAllLowerIncidentCells(kspace, *bi, cells_accum);
}
 
template <typename TLinearAlgebraBackend, typename TInteger>
template <typename KSpace, typename CellsAccum, typename MeasureAccum>
void
DGtal::DiscreteExteriorCalculusFactory<TLinearAlgebraBackend, TInteger>::accumulateAllLowerIncidentCells(const KSpace& kspace, const typename CellsAccum::key_type& cell, CellsAccum& cells_accum, 
    CellsAccum& local_accum, MeasureAccum& cell_to_measure, const double measure)
{
    typedef typename KSpace::Cells Cells;
 
    if (cells_accum.find(cell) == cells_accum.end()) cells_accum[cell] = 0;
    cells_accum[cell]++;
 
    if( kspace.uDim( cell ) == 0 && local_accum.find( cell ) == local_accum.end())
    {
        local_accum[cell] = 0;
        if( cell_to_measure.find(cell) == cell_to_measure.end() ) cell_to_measure[cell] = 0.;
        cell_to_measure[cell] += measure;
    }
 
    const Cells border = kspace.uLowerIncident(cell);
    for (typename Cells::ConstIterator bi=border.begin(), be=border.end(); bi!=be; bi++)
        accumulateAllLowerIncidentCells(kspace, *bi, cells_accum, local_accum, cell_to_measure, measure);
}
 
template <typename TLinearAlgebraBackend, typename TInteger>
template <DGtal::Dimension dimEmbedded, typename TNSCellConstIterator>
DGtal::DiscreteExteriorCalculus<dimEmbedded, TNSCellConstIterator::value_type::Point::dimension, TLinearAlgebraBackend, TInteger>
DGtal::DiscreteExteriorCalculusFactory<TLinearAlgebraBackend, TInteger>::createFromNSCells(const TNSCellConstIterator& begin, const TNSCellConstIterator& end, const bool add_border)
{
    BOOST_CONCEPT_ASSERT(( boost_concepts::SinglePassIteratorConcept<TNSCellConstIterator> ));
    BOOST_CONCEPT_ASSERT(( boost_concepts::ReadableIteratorConcept<TNSCellConstIterator> ));
 
    typedef DGtal::DiscreteExteriorCalculus<dimEmbedded, TNSCellConstIterator::value_type::Point::dimension, TLinearAlgebraBackend, TInteger> Calculus;
    typedef typename Calculus::Cell Cell;
    typedef typename Calculus::SCell SCell;
    typedef typename Calculus::Scalar Scalar;
    typedef typename Calculus::KSpace KSpace;
    typedef typename KSpace::Cells Cells;
 
    BOOST_STATIC_ASSERT(( boost::is_convertible<typename TNSCellConstIterator::value_type, const SCell>::value ));
 
    Calculus calculus;
 
    // compute dimEmbedded-1 cells border
    typedef std::map<Cell, int> CellsAccum;
    CellsAccum border_accum;
    CellsAccum lower_accum;
    for (TNSCellConstIterator ci=begin; ci!=end; ++ci)
    {
        const SCell cell_signed = *ci;
        const Dimension cell_dim = calculus.myKSpace.sDim(cell_signed);
        ASSERT_MSG( cell_dim == dimEmbedded, "wrong n-cell dimension" );
        boost::ignore_unused_variable_warning(cell_dim);
 
        calculus.insertSCell(cell_signed);
 
        const Cell cell = calculus.myKSpace.unsigns(cell_signed);
        const Cells border = calculus.myKSpace.uLowerIncident(cell);
        for (typename Cells::ConstIterator bi=border.begin(), be=border.end(); bi!=be; bi++)
        {
            const Cell cell_border = *bi;
            if (!add_border)
            {
                if (border_accum.find(cell_border) == border_accum.end()) border_accum[cell_border] = 0;
                border_accum[cell_border]++;
            }
            accumulateAllLowerIncidentCells(calculus.myKSpace, cell_border, lower_accum);
        }
    }
    ASSERT( !add_border || border_accum.empty() );
 
    typedef std::set<Cell> CellsSet;
    CellsSet border;
    for (typename CellsAccum::const_iterator bai=border_accum.begin(), bae=border_accum.end(); bai!=bae; bai++)
    {
        ASSERT( bai->second > 0 );
        //ASSERT( bai->second < 3 );
        if (bai->second >= 2) continue;
        insertAllLowerIncidentCells(calculus.myKSpace, bai->first, border);
    }
    ASSERT( !add_border || border.empty() );
 
    // normalize cell size and set flipped flag
    for (typename CellsAccum::const_iterator lai=lower_accum.begin(), lae=lower_accum.end(); lai!=lae; ++lai)
    {
        const Cell cell = lai->first;
        if (border.find(cell) != border.end()) continue;
 
        const DGtal::Dimension dual_dim = Calculus::dimensionEmbedded-calculus.myKSpace.uDim(cell);
        ASSERT( dual_dim > 0 );
        ASSERT( dual_dim <= Calculus::dimensionEmbedded );
 
        const Scalar factor = pow(.5, 2*dual_dim-1);
        const Scalar dual_size = lai->second * factor;
        ASSERT( dual_size > 0 );
 
        const SCell cell_signed = calculus.myKSpace.signs(cell, KSpace::POS);
        calculus.insertSCell(cell_signed, 1, dual_size);
    }
 
    calculus.updateIndexes();
 
    return calculus;
}
 
template <typename TLinearAlgebraBackend, typename TInteger>
template <DGtal::Dimension dimEmbedded, typename TNSCellConstIterator, typename TSCellMeasureFunctor>
DGtal::DiscreteExteriorCalculus<dimEmbedded, TNSCellConstIterator::value_type::Point::dimension, TLinearAlgebraBackend, TInteger>
DGtal::DiscreteExteriorCalculusFactory<TLinearAlgebraBackend, TInteger>::createFromNSCells(const TNSCellConstIterator& begin, const TNSCellConstIterator& end, 
    const TSCellMeasureFunctor& normalFunctor, const double h, const bool add_border)
{
    BOOST_CONCEPT_ASSERT(( boost_concepts::SinglePassIteratorConcept<TNSCellConstIterator> ));
    BOOST_CONCEPT_ASSERT(( boost_concepts::ReadableIteratorConcept<TNSCellConstIterator> ));
 
    typedef DGtal::DiscreteExteriorCalculus<dimEmbedded, TNSCellConstIterator::value_type::Point::dimension, TLinearAlgebraBackend, TInteger> Calculus;
    typedef typename Calculus::Cell Cell;
    typedef typename Calculus::SCell SCell;
    typedef typename Calculus::Scalar Scalar;
    typedef typename Calculus::KSpace KSpace;
    typedef typename KSpace::Cells Cells;
 
    BOOST_STATIC_ASSERT(( boost::is_convertible<typename TNSCellConstIterator::value_type, const SCell>::value ));
 
    typedef typename TSCellMeasureFunctor::Quantity Quantity;
    std::vector<Quantity> measures;
    std::back_insert_iterator< std::vector<Quantity> > back_insert( measures );
    normalFunctor.eval(begin, end, back_insert);
    typename std::vector<Quantity>::const_iterator measure_it = measures.begin();
 
    Calculus calculus;
    // compute dimEmbedded-1 cells border
    std::map<Cell, double> cell_to_measure;
 
    typedef std::map<Cell, int> CellsAccum;
    CellsAccum border_accum;
    CellsAccum lower_accum;
    for (TNSCellConstIterator ci=begin; ci!=end; ++ci)
    {
        const SCell cell_signed = *ci;
        const Dimension cell_dim = calculus.myKSpace.sDim(cell_signed);
        ASSERT_MSG( cell_dim == dimEmbedded, "wrong n-cell dimension" );
        boost::ignore_unused_variable_warning(cell_dim);
 
        const int orth_dir = calculus.myKSpace.sOrthDir( cell_signed );
        const double measure = pow(h, dimEmbedded) * fabs( (*measure_it)[orth_dir] );
        ++measure_it;
 
        calculus.insertSCell(cell_signed, measure, 1.);
 
        const Cell cell = calculus.myKSpace.unsigns(cell_signed);
        const Cells border = calculus.myKSpace.uLowerIncident(cell);
        CellsAccum local_accum;
        for (typename Cells::ConstIterator bi=border.begin(), be=border.end(); bi!=be; bi++)
        {
            const Cell cell_border = *bi;
            if (!add_border)
            {
                if (border_accum.find(cell_border) == border_accum.end()) border_accum[cell_border] = 0;
                border_accum[cell_border]++;
            }
            accumulateAllLowerIncidentCells(calculus.myKSpace, cell_border, lower_accum, local_accum, cell_to_measure, measure / 4.);
        }
    }
    ASSERT( !add_border || border_accum.empty() );
 
    typedef std::set<Cell> CellsSet;
    CellsSet border;
    for (typename CellsAccum::const_iterator bai=border_accum.begin(), bae=border_accum.end(); bai!=bae; bai++)
    {
        ASSERT( bai->second > 0 );
        //ASSERT( bai->second < 3 );
        if (bai->second >= 2) continue;
        insertAllLowerIncidentCells(calculus.myKSpace, bai->first, border);
    }
    ASSERT( !add_border || border.empty() );
 
    // normalize cell size and set flipped flag
    for (typename CellsAccum::const_iterator lai=lower_accum.begin(), lae=lower_accum.end(); lai!=lae; ++lai)
    {
        const Cell cell = lai->first;
        if (border.find(cell) != border.end()) continue;
        const SCell cell_signed = calculus.myKSpace.signs(cell, KSpace::POS);
 
        if( cell_to_measure.find( cell ) != cell_to_measure.end() )
        {
            const double dual_measure = cell_to_measure.find( cell )->second;
            if(cell_to_measure.find( cell ) == cell_to_measure.end()) trace.warning() << "HOUUU" << std::endl;
            calculus.insertSCell(cell_signed, 1, dual_measure);
            continue;
        }
 
        const DGtal::Dimension dual_dim = Calculus::dimensionEmbedded-calculus.myKSpace.uDim(cell);
        ASSERT( dual_dim > 0 );
        ASSERT( dual_dim <= Calculus::dimensionEmbedded );
 
        const Scalar factor = pow(.5, 2*dual_dim-1);
        const Scalar dual_size = lai->second * factor;
        ASSERT( dual_size > 0 );
 
        calculus.insertSCell(cell_signed, 1, dual_size);
    }
 
    calculus.updateIndexes();
 
    return calculus;
}
 
//                                                                           //
///////////////////////////////////////////////////////////////////////////////