WireCell::Gen::ImpactZipper Class Reference

#include <ImpactZipper.h>

Public Member Functions
	ImpactZipper (IPlaneImpactResponse::pointer pir, BinnedDiffusion &bd)
virtual	~ImpactZipper ()
Waveform::realseq_t	waveform (int wire) const

Private Attributes
IPlaneImpactResponse::pointer	m_pir
BinnedDiffusion &	m_bd

Detailed Description

An ImpactZipper "zips" up through all the impact positions along a wire plane convolving the response functions and the local drifted charge distribution producing a waveform on each central wire.

Definition at line 16 of file ImpactZipper.h.

Constructor & Destructor Documentation

Gen::ImpactZipper::ImpactZipper	(	IPlaneImpactResponse::pointer	pir,
		BinnedDiffusion &	bd
	)

Definition at line 8 of file ImpactZipper.cxx.

    :m_pir(pir), m_bd(bd)
{
    
}

Gen::ImpactZipper::~ImpactZipper ( )

virtual

Definition at line 16 of file ImpactZipper.cxx.

{
}

Member Function Documentation

Waveform::realseq_t Gen::ImpactZipper::waveform

(

int

wire

)

const

Return the wire's waveform. If the response functions are just field response (ie, instantaneous current) then the waveforms are expressed as current integrated over each sample bin and thus in units of charge. If the response functions include electronics response then the waveforms are in units of voltage representing the sampling of the output of the FEE amplifiers.

Definition at line 21 of file ImpactZipper.cxx.

{
    const double pitch_range = m_pir->pitch_range();

    const auto pimpos = m_bd.pimpos();
    const auto rb = pimpos.region_binning();
    const auto ib = pimpos.impact_binning();
    const double wire_pos = rb.center(iwire);

    const int min_impact = ib.edge_index(wire_pos - 0.5*pitch_range);
    const int max_impact = ib.edge_index(wire_pos + 0.5*pitch_range);
    const int nsamples = m_bd.tbins().nbins();
    Waveform::compseq_t total_spectrum(nsamples, Waveform::complex_t(0.0,0.0));


    int nfound=0;
    const bool share=true;
    const Waveform::complex_t complex_one_half(0.5,0.0);

    // The BinnedDiffusion is indexed by absolute impact and the
    // PlaneImpactResponse relative impact.
    for (int imp = min_impact; imp <= max_impact; ++imp) {
        
        // ImpactData
        auto id = m_bd.impact_data(imp);
        if (!id) {
            // common as we are scanning all impacts covering a wire
            // fixme: is there a way to predict this to avoid the query?
            //std::cerr << "ImpactZipper: no data for absolute impact number: " << imp << std::endl;
            continue;
        }
        
        const Waveform::compseq_t& charge_spectrum = id->spectrum();
        // for interpolation
        const Waveform::compseq_t& weightcharge_spectrum = id->weight_spectrum();
   
        if (charge_spectrum.empty()) {
            // should not happen
            std::cerr << "ImpactZipper: no charge for absolute impact number: " << imp << std::endl;
            continue;
        }
        if (weightcharge_spectrum.empty()) {
            // weight == 0, should not happen
            std::cerr << "ImpactZipper: no weight charge for absolute impact number: " << imp << std::endl;
            continue;
        }

        const double imp_pos = ib.center(imp);
        const double rel_imp_pos = imp_pos - wire_pos;
        //std::cerr << "IZ: " << " imp=" << imp << " imp_pos=" << imp_pos << " rel_imp_pos=" << rel_imp_pos << std::endl;

        Waveform::compseq_t conv_spectrum(nsamples, Waveform::complex_t(0.0,0.0));
        if (share) {            // fixme: make a configurable option
            TwoImpactResponses two_ir = m_pir->bounded(rel_imp_pos);
            if (!two_ir.first || !two_ir.second) {
                //std::cerr << "ImpactZipper: no impact response for absolute impact number: " << imp << std::endl;
                continue;
            }
            // fixme: this is average, not interpolation.
            Waveform::compseq_t rs1 = two_ir.first->spectrum();            
            Waveform::compseq_t rs2 = two_ir.second->spectrum();            
            
            for (int ind=0; ind < nsamples; ++ind) {
                //conv_spectrum[ind] = complex_one_half*(rs1[ind]+rs2[ind])*charge_spectrum[ind];
            
                // linear interpolation: wQ*rs1 + (Q-wQ)*rs2
                conv_spectrum[ind] = weightcharge_spectrum[ind]*rs1[ind]+(charge_spectrum[ind]-weightcharge_spectrum[ind])*rs2[ind];
                /* debugging */
                /* if(iwire == 1000 && ind>1000 && ind<2000) { */
                /* std::cerr<<"rs1 spectrum: "<<imp<<"|"<<ind<<": "<<std::abs(rs1[ind])<<std::endl; */
                /* std::cerr<<"rs2 spectrum: "<<imp<<"|"<<ind<<": "<<std::abs(rs2[ind])<<std::endl; */
                /* std::cerr<<"rs1 charge spectrum "<<ind<<": "<<weightcharge_spectrum[ind]<<std::endl; */
                /* std::cerr<<"rs2 charge spectrum "<<ind<<": "<<charge_spectrum[ind]-weightcharge_spectrum[ind]<<std::endl; */
              /* //std::cerr<<"rs1 charge spectrum "<<ind<<": "<<complex_one_half*charge_spectrum[ind]<<std::endl; */
              /* //std::cerr<<"rs2 charge spectrum "<<ind<<": "<<complex_one_half*charge_spectrum[ind]<<std::endl; */
                /* } */
            }
        }
        else {
            auto ir = m_pir->closest(rel_imp_pos);
            if (! ir) {
                // std::cerr << "ImpactZipper: no impact response for absolute impact number: " << imp << std::endl;
                continue;
            }
            Waveform::compseq_t response_spectrum = ir->spectrum();
            for (int ind=0; ind < nsamples; ++ind) {
                conv_spectrum[ind] = response_spectrum[ind]*charge_spectrum[ind];
            }
        }

        ++nfound;
        // std::cerr << "ImpactZipper: found:"<<nfound<<" for absolute impact number " << imp
        //           << " csize=" << csize << " rsize=" << rsize << " rebin=" << rebinfactor
        //           << std::endl;

        Waveform::increase(total_spectrum, conv_spectrum);
    }
    //std::cerr << "ImpactZipper: found " << nfound << " in abs impact: ["  << min_impact << ","<< max_impact << "]\n";

    // Clear memory assuming next call is iwire+1.
    // fixme: this is a dumb way to go. Better to make an iterator.
    m_bd.erase(0, min_impact); 

    if (!nfound) {
        return Waveform::realseq_t(nsamples, 0.0);
    }
    
    auto waveform = Waveform::idft(total_spectrum);

    return waveform;
}

Member Data Documentation

BinnedDiffusion& WireCell::Gen::ImpactZipper::m_bd

private

Definition at line 19 of file ImpactZipper.h.

IPlaneImpactResponse::pointer WireCell::Gen::ImpactZipper::m_pir

private

Definition at line 18 of file ImpactZipper.h.

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The documentation for this class was generated from the following files:

• wire-cell-build/gen/inc/WireCellGen/ImpactZipper.h
• wire-cell-build/gen/src/ImpactZipper.cxx