WireCell::Gen::Drifter Class Reference

#include <Drifter.h>

Inheritance diagram for WireCell::Gen::Drifter:

Classes
struct	DepoTimeCompare
struct	IsInsideBulk
struct	IsInsideResp
struct	Xregion

Public Member Functions
	Drifter ()
virtual	~Drifter ()
virtual void	reset ()
virtual bool	operator() (const input_pointer &depo, output_queue &outq)
	The calling signature: More...
virtual void	configure (const WireCell::Configuration &config)
	WireCell::IConfigurable interface. More...
virtual WireCell::Configuration	default_configuration () const
	Optional, override to return a hard-coded default configuration. More...
IDepo::pointer	transport (IDepo::pointer depo)
double	proper_time (IDepo::pointer depo)
bool	insert (const input_pointer &depo)
void	flush (output_queue &outq)
void	flush_ripe (output_queue &outq, double now)
virtual void	set_lifetime (double lifetime_to_set)
Public Member Functions inherited from WireCell::IDrifter
virtual	~IDrifter ()
virtual std::string	signature ()
Public Member Functions inherited from WireCell::IQueuedoutNode< IDepo, IDepo >
virtual	~IQueuedoutNode ()
virtual bool	operator() (const boost::any &anyin, queuedany &outanyq)
	The calling signature: More...
virtual std::vector< std::string >	input_types ()
virtual std::vector< std::string >	output_types ()
Public Member Functions inherited from WireCell::IQueuedoutNodeBase
virtual	~IQueuedoutNodeBase ()
virtual NodeCategory	category ()
	Return the behavior category type. More...
virtual int	concurrency ()
	By default assume all subclasses maintain state. More...
Public Member Functions inherited from WireCell::INode
virtual	~INode ()
Public Member Functions inherited from WireCell::IComponent< INode >
virtual	~IComponent ()
Public Member Functions inherited from WireCell::Interface
virtual	~Interface ()
Public Member Functions inherited from WireCell::IConfigurable
virtual	~IConfigurable ()
Public Member Functions inherited from WireCell::IComponent< IConfigurable >
virtual	~IComponent ()

Private Attributes
IRandom::pointer	m_rng
std::string	m_rng_tn
double	m_DL
double	m_DT
double	m_lifetime
bool	m_fluctuate
double	m_speed
double	m_toffset
int	n_dropped
int	n_drifted
std::vector< Xregion >	m_xregions
Log::logptr_t	l

Additional Inherited Members
Public Types inherited from WireCell::IDrifter
typedef std::shared_ptr< IDrifter >	pointer
Public Types inherited from WireCell::IQueuedoutNode< IDepo, IDepo >
typedef std::shared_ptr< IQueuedoutNodeBase >	pointer
typedef IDepo	input_type
typedef IDepo	output_type
typedef std::shared_ptr< const IDepo >	input_pointer
typedef std::shared_ptr< const IDepo >	output_pointer
typedef std::deque< output_pointer >	output_queue
Public Types inherited from WireCell::IQueuedoutNodeBase
typedef std::shared_ptr< IQueuedoutNodeBase >	pointer
typedef std::deque< boost::any >	queuedany
Public Types inherited from WireCell::INode
enum	NodeCategory {   unknown, sourceNode, sinkNode, functionNode,   queuedoutNode, joinNode, splitNode, faninNode,   fanoutNode, multioutNode, hydraNode }
Public Types inherited from WireCell::IComponent< INode >
typedef std::shared_ptr< INode >	pointer
	Access subclass facet by pointer. More...
typedef std::vector< pointer >	vector
	Vector of shared pointers. More...
Public Types inherited from WireCell::Interface
typedef std::shared_ptr< Interface >	pointer
Public Types inherited from WireCell::IComponent< IConfigurable >
typedef std::shared_ptr< IConfigurable >	pointer
	Access subclass facet by pointer. More...
typedef std::vector< pointer >	vector
	Vector of shared pointers. More...

Detailed Description

This component drifts depos bounded by planes perpendicular to the X-axis. The boundary planes are specified with the "xregions" list. Each list is an object fully specified with a "cathode" an "anode" and a "response" attribute giving X locations in the same coordinate system as depos of three planes.

• cathode :: a plane which bounds the maximum possible drift.
• anode :: a plane which bounds the minimum possible drift.
• response :: a plane to which all depositions are drifted.

If "anode" is not given then its value is take to be that of "response" and vice versa and at least one must be specified. A "cathode" value must be specified.

Any depo not falling between "anode" and "cathode" will be dropped.

Any depo falling between "response" and "cathode" will be drifted to the "response" plane.

Any depo falling between "anode" and "response" will be ANTI-DRIFTED to the "response" plane. Ie, it will be "BACKED UP" in space an time as if it had be produced earlier and at the response plane.

Input depositions must be ordered in absolute time (their current time) and output depositions are produced ordered by their time after being drifted to the response plane.

Diffusion and absorption effects and also, optionally, fluctuations are applied. Fano factor and Recombination are not applied in this component (see IRecombinationModel implementations).

Typically a drifter is used just prior to a ductor and in such cases the "response" plane should be made coincident with the non-physical "response plane" which defines the starting point for the field response functions. The location of the response plane realtive to the wire planes can be found using:

$ wriecell-sigproc response-info garfield-1d-3planes-21wires-6impacts-dune-v1.json.bz2 origin:10.00 cm, period:0.10 us, tstart:0.00 us, speed:1.60 mm/us, axis:(1.00,0.00,0.00) plane:0, location:9.4200mm, pitch:4.7100mm plane:1, location:4.7100mm, pitch:4.7100mm plane:2, location:0.0000mm, pitch:4.7100mm

Here, "origin" gives the location of the response plane. The location of the wire planes according to wire geometry can be similarly dumped.

$ wirecell-util wires-info protodune-wires-larsoft-v3.json.bz2 anode:0 face:0 X=[-3584.63,-3584.63]mm Y=[6066.70,6066.70]mm Z=[7.92,7.92]mm 0: x=-3584.63mm dx=9.5250mm 1: x=-3589.39mm dx=4.7620mm 2: x=-3594.16mm dx=0.0000mm .... anode:5 face:1 X=[3584.63,3584.63]mm Y=[6066.70,6066.70]mm Z=[6940.01,6940.01]mm 0: x=3584.63mm dx=-9.5250mm 1: x=3589.39mm dx=-4.7620mm 2: x=3594.16mm dx=0.0000mm

Note, as can see, these two sources of information may not be consistent w.r.t. the inter-plane separation distance (4.71mm and 4.76mm, respectively). This mismatch will result in a relative shift in time between the planes for various waveform features (eg induction zero crossings and collection peak).

For the example above, likely candidates for "anode" X locations are:

x = -3594.16mm + 10cm

and

x = +3594.16mm - 10cm

Definition at line 102 of file Drifter.h.

Constructor & Destructor Documentation

Gen::Drifter::Drifter

(

)

Definition at line 59 of file Drifter.cxx.

    : m_rng(nullptr)
    , m_rng_tn("Random")
    , m_DL(7.2 * units::centimeter2/units::second) // from arXiv:1508.07059v2
    , m_DT(12.0 * units::centimeter2/units::second) // ditto
    , m_lifetime(8*units::ms) // read off RHS of figure 6 in MICROBOONE-NOTE-1003-PUB
    , m_fluctuate(true)
    , m_speed(1.6*units::mm/units::us)
    , m_toffset(0.0)
    , n_dropped(0)
    , n_drifted(0)
    , l(Log::logger("sim"))
{
}

Gen::Drifter::~Drifter ( )

virtual

Definition at line 74 of file Drifter.cxx.

{
}

Member Function Documentation

void Gen::Drifter::configure ( const WireCell::Configuration &  config )

virtual

WireCell::IConfigurable interface.

Implements WireCell::IConfigurable.

Definition at line 93 of file Drifter.cxx.

{
    reset();

    m_rng_tn = get(cfg, "rng", m_rng_tn);
    m_rng = Factory::find_tn<IRandom>(m_rng_tn);

    m_DL = get<double>(cfg, "DL", m_DL);
    m_DT = get<double>(cfg, "DT", m_DT);
    m_lifetime = get<double>(cfg, "lifetime", m_lifetime);
    m_fluctuate = get<bool>(cfg, "fluctuate", m_fluctuate);
    m_speed = get<double>(cfg, "drift_speed", m_speed);
    m_toffset = get<double>(cfg, "time_offset", m_toffset);

    auto jxregions = cfg["xregions"];
    if (jxregions.empty()) {
        l->critical("no xregions given so I can do nothing");
        THROW(ValueError() << errmsg{"no xregions given"});
    }
    for (auto jone : jxregions) {
        m_xregions.push_back(Xregion(jone));
    }
    l->debug("Drifter: time offset: {} ms, drift speed: {} mm/us",
            m_toffset/units::ms, m_speed/(units::mm/units::us));
}

WireCell::Configuration Gen::Drifter::default_configuration ( ) const

virtual

Optional, override to return a hard-coded default configuration.

Reimplemented from WireCell::IConfigurable.

Definition at line 78 of file Drifter.cxx.

{
    Configuration cfg;
    cfg["DL"] = m_DL;
    cfg["DT"] = m_DT;
    cfg["lifetime"] = m_lifetime;
    cfg["fluctuate"] = m_fluctuate;
    cfg["drift_speed"] = m_speed;
    cfg["time_offset"] = m_toffset;

    // see comments in .h file
    cfg["xregions"] = Json::arrayValue;
    return cfg;
}

void Gen::Drifter::flush

(

output_queue &

outq

)

Definition at line 206 of file Drifter.cxx.

{
    for (auto& xr : m_xregions) {
        l->debug("xregion: anode: {} mm, response: {} mm, cathode: {} mm, flushing {}",
                 xr.anode/units::mm, xr.response/units::mm,
                 xr.cathode/units::mm, xr.depos.size());
        outq.insert(outq.end(), xr.depos.begin(), xr.depos.end());
        xr.depos.clear();
    }
    std::sort(outq.begin(), outq.end(), by_time);
    outq.push_back(nullptr);
}

void Gen::Drifter::flush_ripe	(	output_queue &	outq,
		double	now
	)

Definition at line 219 of file Drifter.cxx.

{
    // It might be faster to use a sorted set which would avoid an
    // exhaustive iteration of each depos stash.  Or not.
    for (auto& xr : m_xregions) {
        if (xr.depos.empty()) {
            continue;
        }

        Xregion::ordered_depos_t::const_iterator depo_beg=xr.depos.begin(), depo_end=xr.depos.end();
        Xregion::ordered_depos_t::iterator depoit = depo_beg;
        while (depoit != depo_end) {
            if ((*depoit)->time() < now) {
                ++depoit;
                continue;
            }
            break;
        }
        if (depoit == depo_beg) {
            continue;
        }
        
        outq.insert(outq.end(), depo_beg, depoit);
        xr.depos.erase(depo_beg, depoit);
    }
    if (outq.empty()) {
        return;
    }
    std::sort(outq.begin(), outq.end(), by_time);
}

bool Gen::Drifter::insert

(

const input_pointer &

depo

)

Definition at line 125 of file Drifter.cxx.

{
    // electrical charge to drift.  Electrons should be negative
    const double Qi = depo->charge();
    if (Qi == 0.0) {
        // Yes, some silly depo sources ask us to drift nothing....
        return false;
    }

    // Find which X region to add, or reject.  Maybe there is a faster
    // way to do this than a loop.  For example, the regions could be
    // examined in order to find some regular binning of the X axis
    // and then at worse only explicitly check extent partial bins
    // near to their edges.



    double respx = 0, direction = 0.0;

    auto xrit = std::find_if(m_xregions.begin(), m_xregions.end(), 
                             Gen::Drifter::IsInsideResp(depo));
    if (xrit != m_xregions.end()) {
        // Back up in space and time.  This is a best effort fudge.  See:
        // https://github.com/WireCell/wire-cell-gen/issues/22

        respx = xrit->response;
        direction = -1.0;
    }
    else {
        xrit = std::find_if(m_xregions.begin(), m_xregions.end(), 
                            Gen::Drifter::IsInsideBulk(depo));
        if (xrit != m_xregions.end()) { // in bulk
            respx = xrit->response;
            direction = 1.0;
        }
    }
    if (xrit == m_xregions.end()) {
        return false;           // outside both regions
    }

    Point pos = depo->pos();
    const double dt = std::abs((respx - pos.x())/m_speed);
    pos.x(respx);

    
    double dL = depo->extent_long();
    double dT = depo->extent_tran();

    double Qf = Qi;
    if (direction > 0) {
        // final number of electrons after drift if no fluctuation.
        const double absorbprob = 1 - exp(-dt/m_lifetime);

        double dQ = Qi * absorbprob;

        // How many electrons remain, with fluctuation.
        // Note: fano/recomb fluctuation should be done before the depo was first made.
        if (m_fluctuate) {
            double sign = 1.0;
            if (Qi < 0) {
                sign = -1.0;
            }
            dQ = sign*m_rng->binomial((int)std::abs(Qi), absorbprob);
        }
        Qf = Qi - dQ;

        dL = sqrt(2.0*m_DL*dt + dL*dL);
        dT = sqrt(2.0*m_DT*dt + dT*dT);
    }

    auto newdepo = make_shared<SimpleDepo>(depo->time() + direction*dt + m_toffset, pos, Qf, depo, dL, dT);
    xrit->depos.insert(newdepo);
    return true;
}    

bool Gen::Drifter::operator() ( const input_pointer &  in, output_queue &  outq  )

virtual

The calling signature:

Implements WireCell::IQueuedoutNode< IDepo, IDepo >.

Definition at line 252 of file Drifter.cxx.

{
    if (m_speed <= 0.0) {
        l->error("illegal drift speed: {}", m_speed);
        return false;
    }

    if (!depo) {                // no more inputs expected, EOS flush

        flush(outq);

        if (n_dropped) {
            l->debug("at EOS, dropped {} / {} depos from stream, outside of all {} drift regions", n_dropped, n_dropped+n_drifted, m_xregions.size());
        }
        n_drifted = n_dropped = 0;
        return true;
    }

    bool ok = insert(depo);
    if (!ok) {
        ++n_dropped;            // depo is outside our regions but
        return true;            // nothing changed, so just bail
    }
    ++n_drifted;

    // At this point, time has advanced and maybe some drifted repos
    // are ripe for removal.

    flush_ripe(outq, depo->time());

    return true;
}

double WireCell::Gen::Drifter::proper_time

(

IDepo::pointer

depo

)

void Gen::Drifter::reset ( void  )

virtual

Optional hook to be implemented in order to reset after an end of stream is encountered. Fixme: this should be removed.

Reimplemented from WireCell::INode.

Definition at line 119 of file Drifter.cxx.

{
    m_xregions.clear();
}

virtual void WireCell::Gen::Drifter::set_lifetime ( double  lifetime_to_set )

inlinevirtual

Definition at line 129 of file Drifter.h.

                                                             {
                m_lifetime = lifetime_to_set;
            };

IDepo::pointer WireCell::Gen::Drifter::transport

(

IDepo::pointer

depo

)

Member Data Documentation

Log::logptr_t WireCell::Gen::Drifter::l

private

Definition at line 183 of file Drifter.h.

double WireCell::Gen::Drifter::m_DL

private

Definition at line 140 of file Drifter.h.

double WireCell::Gen::Drifter::m_DT

private

Definition at line 140 of file Drifter.h.

bool WireCell::Gen::Drifter::m_fluctuate

private

Definition at line 146 of file Drifter.h.

double WireCell::Gen::Drifter::m_lifetime

private

Definition at line 143 of file Drifter.h.

IRandom::pointer WireCell::Gen::Drifter::m_rng

private

Definition at line 131 of file Drifter.h.

std::string WireCell::Gen::Drifter::m_rng_tn

private

Definition at line 136 of file Drifter.h.

double WireCell::Gen::Drifter::m_speed

private

Definition at line 148 of file Drifter.h.

double WireCell::Gen::Drifter::m_toffset

private

Definition at line 149 of file Drifter.h.

std::vector<Xregion> WireCell::Gen::Drifter::m_xregions

private

Definition at line 170 of file Drifter.h.

int WireCell::Gen::Drifter::n_drifted

private

Definition at line 151 of file Drifter.h.

int WireCell::Gen::Drifter::n_dropped

private

Definition at line 151 of file Drifter.h.

---

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

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