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Gyoto::Photon::Refined Class Reference

Refine last step of integration in a Photon. More...

#include <GyotoPhoton.h>

Inheritance diagram for Gyoto::Photon::Refined:
Gyoto::Photon Gyoto::Worldline Gyoto::SmartPointee Gyoto::Hook::Listener

Public Member Functions

 Refined (Photon *parent, size_t i, int dir, double step_max)
 Constructor.
virtual void transmit (size_t i, double t)
 Update transmission both in *this and in *parent_.
virtual std::string className () const
 "Photon"
virtual std::string className_l () const
 "photon"
Photonclone () const
 Cloner.
virtual double getMass () const
 Return 0.
void setAstrobj (SmartPointer< Astrobj::Generic >)
 Set Photon::object_.
SmartPointer< Astrobj::GenericgetAstrobj () const
 Get Photon::object_.
void setSpectrometer (SmartPointer< Spectrometer::Generic > spr)
 Set Photon::spectro_.
SmartPointer
< Spectrometer::Generic
getSpectrometer () const
 Get Photon::spectro_.
void setFreqObs (double)
 Set Photon::freq_obs__.
double getFreqObs () const
 Get Photon::freq_obs__.
void setInitialCondition (SmartPointer< Metric::Generic > gg, SmartPointer< Astrobj::Generic > obj, const double coord[8])
 Set or re-set the initial condition prior to integration.
void setInitialCondition (SmartPointer< Metric::Generic > gg, SmartPointer< Astrobj::Generic > obj, SmartPointer< Screen > screen, double d_alpha, double d_delta)
 Set or re-set the initial condition prior to integration.
void setInitialCondition (SmartPointer< Metric::Generic > gg, const double coord[8], const int dir)
 Set or re-set the initial condition prior to integration.
int hit (Astrobj::Properties *data=NULL)
 Integrate the geodesic.
double findMin (Functor::Double_constDoubleArray *object, double t1, double t2, double &tmin, double threshold=DBL_MIN)
 Find minimum of photon–object distance.
void findValue (Functor::Double_constDoubleArray *object, double value, double tinside, double &toutside)
 Find date for which the photon is at a given distance from the object.
void fillElement (FactoryMessenger *fmp)
 Write XML description.
virtual void fillElement (FactoryMessenger *fmp) const
 XML output.
void resetTransmission ()
 Set transmission to 1 for each channel as well as scalar transmission.
double getTransmission (size_t i) const
 Get transmission.
double const * getTransmission () const
 Get Photon::transmission_.
double getTransmissionMax () const
 Get maximum transmission;.
size_t getImin () const
 Get index of computed date furthest in the past.
size_t getImax () const
 Get index of computed date furthest in the future.
size_t getI0 () const
 Get index of initial condition.
void setMetric (SmartPointer< Metric::Generic >)
 Set metric Smartpointer.
SmartPointer< Metric::GenericgetMetric () const
 Get metric.
virtual void setInitCoord (const double coord[8], int dir=0)
 Set Initial coordinate.
virtual void setInitCoord (double pos[4], double vel[3], int dir=1)
 Set initial coordinate.
virtual void setPosition (double pos[4])
 Set initial 4-position.
virtual void setVelocity (double vel[3])
 Set initial 3-velocity.
void reset ()
 Forget integration, keeping initial contition.
void reInit ()
 Reset and recompute particle properties.
void setDelta (const double delta)
 Set delta.
void setDelta (double, const std::string &unit)
 Set default step in specified units.
double getDelta () const
 Get delta.
double getDelta (const std::string &unit) const
 Get default step in specified units.
double getTmin () const
 Get tmin value.
void setTmin (double tlim)
 Set tmin to a given value.
void adaptive (bool mode)
 Set adaptive_.
bool adaptive () const
 Get adaptive_.
void maxiter (size_t miter)
 Set maxiter_.
size_t maxiter () const
 Get maxiter_.
double const * getCst () const
 Returns the worldline's cst of motion (if any)
void setCst (double const *cst, size_t const ncsts)
 Set Metric-specific constants of motion.
void getInitialCoord (double dest[8]) const
 Get initial coordinate.
void getCoord (size_t index, double dest[8]) const
 Get coordinates corresponding to index.
void getCoord (double const *const dates, size_t const n_dates, double *const x1dest, double *const x2dest, double *const x3dest, double *const x0dot=NULL, double *const x1dot=NULL, double *const x2dot=NULL, double *const x3dot=NULL)
 Get 8-coordinates for specific dates.
void getCoord (double *x0, double *x1, double *x2, double *x3) const
 Get all computed positions.
void getCartesianPos (size_t index, double dest[4]) const
 Get Cartesian expression of 4-position at index.
void xFill (double tlim)
 Fill x0, x1... by integrating the Worldline from previously set inittial condition to time tlim.
virtual int setParameter (std::string name, std::string content, std::string unit)
 Set parameter by name.
virtual void setParameters (FactoryMessenger *fmp)
 Process XML entity Uses wait_pos_ and init_vel_ to make sure setVelocity() is called after setPosition().
size_t get_nelements () const
 Get number of computed dates.
void get_t (double *dest) const
 Get computed dates.
void getCartesian (double const *const dates, size_t const n_dates, double *const x, double *const y, double *const z, double *const xprime=NULL, double *const yprime=NULL, double *const zprime=NULL)
 Get the 6 Cartesian coordinates for specific dates.
void get_xyz (double *x, double *y, double *z) const
 Get 3-position in cartesian coordinates for computed dates.
void checkPhiTheta (double coord[8]) const
 Bring θ in [0,Π] and φ in [0,2Π].
void getSkyPos (SmartPointer< Screen > screen, double *dalpha, double *ddellta, double *dD) const
 Get computed positions in sky coordinates.
void get_dot (double *x0dot, double *x1dot, double *x2dot, double *x3dot) const
 Get computed 4-velocities.
void get_prime (double *x1prime, double *x2prime, double *x3prime) const
 Get computed 3-velocities.
void save_txyz (char *fichierxyz) const
 Save in a file.
void save_txyz (char *const filename, double const t1, double const mass_sun, double const distance_kpc, std::string const unit, SmartPointer< Screen > sc=NULL)
 Save, converted.

Static Public Member Functions

static SmartPointer< PhotonSubcontractor (Gyoto::FactoryMessenger *)
 Instanciate Photon from XML description.

Protected Types

typedef Gyoto::SmartPointer
< Gyoto::SmartPointee
Subcontractor_t (Gyoto::FactoryMessenger *)
 A subcontractor builds an object upon order from the Factory.

Protected Member Functions

void xAllocate ()
 Allocate x0, x1 etc. with default size.
void xAllocate (size_t size)
 Allocate x0, x1 etc. with a specified size.
size_t xExpand (int dir)
 Expand x0, x1 etc... to hold more elements.
virtual void tell (Gyoto::Hook::Teller *)
 This is how a Teller tells.
void incRefCount ()
 Increment the reference counter. Warning: Don't mess with the counter.
int decRefCount ()
 Decrement the reference counter and return current value. Warning: Don't mess with the counter.
int getRefCount ()
 Get the current number of references.

Protected Attributes

Photonparent_
 Parent Photon.
SmartPointer
< Gyoto::Astrobj::Generic
object_
 The astronomical target.
double freq_obs_
 Photon's frequency in observer's frame.
double transmission_freqobs_
 Integrated optical transmission.
SmartPointer
< Spectrometer::Generic
spectro_
 Observer's spectrometer.
double * transmission_
 Integrated optical transmissions.
SmartPointer
< Gyoto::Metric::Generic
metric_
 The Gyoto::Metric in this part of the universe.
double * x0_
 t or T
double * x1_
 r or x
double * x2_
 theta or y
double * x3_
 phi or z
double * x0dot_
 tdot or Tdot
double * x1dot_
 rdot or xdot
double * x2dot_
 thetadot or ydot
double * x3dot_
 phidot or zdot
size_t x_size_
 Size of x0, x1... arrays.
size_t imin_
 Minimum index for which x0, x1... have been computed.
size_t i0_
 Index of initial condition in array.
size_t imax_
 Maximum index for which x0, x1... have been computed.
bool adaptive_
 Whether integration should use adaptive delta.
double delta_
 Initial integrating step ; defaults to 0.01.
double tmin_
 Minimum time for integration, stop integration if t<tmin ; defaults to -DBL_MAX.
double * cst_
 Worldline's csts of motion (if any)
size_t cst_n_
 Number of constants of motion.
int wait_pos_
 Hack in setParameters()
double * init_vel_
 Hack in setParameters()
size_t maxiter_
 Maximum number of iterations when integrating.

Detailed Description

Refine last step of integration in a Photon.

The integration step of a Photon's geodesic is adaptive. This is computationally efficient, but sometimes it is necessary to get the position of a Photon with a finer step. Gyoto::ComplexAstrobj::Impact() is a typical use case.

A Refined photon is linked to its parent. In particular, care is taken so that the parent's to update the parent's transmissions whenever the Refined transmissions are touched.

Don't use this class blindly: what's guaranteed to work is what is used in Gyoto::ComplexAstrobj::Impact().

XML description corresponding to this class is <Photon/>. It supports all the parameters supported by the Gyoto::Worldline class plus an optional <Astrobj/> section to attach a instance of a Gyoto::Astrobj::Generic sub-class.

Member Typedef Documentation

typedef Gyoto::SmartPointer<Gyoto::SmartPointee> Gyoto::SmartPointee::Subcontractor_t(Gyoto::FactoryMessenger *)
inherited

A subcontractor builds an object upon order from the Factory.

Various classes need to provide a subcontractor to be able to instanciate themselves upon order from the Factory. A subcontractor is a function (often a static member function) which accepts a pointer to a FactoryMessenger as unique parameter, communicates with the Factory using this messenger to read an XML description of the object to build, and returns this objet. SmartPointee::Subcontractor_t* is just generic enough a typedef to cast to and from other subcontractor types: Astrobj::Subcontractor_t, Metric::Subcontractor_t, Spectrum::Subcontractor_t. A subcontractor needs to be registered using the relevant Register() function: Astrobj::Register(), Metric::Register(), Spectrum::Register().

Member Function Documentation

void Gyoto::Worldline::checkPhiTheta ( double  coord[8]) const
inherited

Bring θ in [0,Π] and φ in [0,2Π].

checkPhiTheta() Modifies coord if the corrdinates are spherical-like so that coord[2]=theta is in [0,pi] and coord[3]=phi is in [0,2pi]. Important to use in all astrobj in spherical coordinates to prevent "z-axis problems".

virtual void Gyoto::Worldline::fillElement ( FactoryMessenger fmp) const
virtualinherited

XML output.

Derived classes implementations should implement fillElement to save their parameters to XML and call the generic implementation to save generic parts such as adaptive_: Worldline::fillElement(fmp).

Reimplemented in Gyoto::Astrobj::Star.

double Gyoto::Photon::findMin ( Functor::Double_constDoubleArray object,
double  t1,
double  t2,
double &  tmin,
double  threshold = DBL_MIN 
)
inherited

Find minimum of photon–object distance.

Return the minimum of (*object)(this->getCoord()) between t1 and t2. The date of this minimum is returned in tmin.

Parameters
[in]objectthe distance to minimize is given by object->operator()(). This method is in particular implemented by the subclasses of Astrobj::Standard.
[in]t1date
[in]t2date
[out]tminon output, date correspondig to the minimum
[in]thresholdstop searching for a minimum if a value < threshold is found (very often, we just want to find a date below the threshold, not the accurate minimum).
void Gyoto::Photon::findValue ( Functor::Double_constDoubleArray object,
double  value,
double  tinside,
double &  toutside 
)
inherited

Find date for which the photon is at a given distance from the object.

Parameters
[in]objectObject, must implement operator() (e.g. Astrobj::Standard, ThinDisk::Standard)
[in]valueThe value to find
[in]tinsideA date for which object->Astrobj::operator()(Photon::getCoord()) is < value
[in,out]toutsideOn input: a date for which object->Astrobj::operator()(Photon::getCoord()) is > value. on output, (*object)(getCoord(toutside)) is < value, very close to value. toutside is closer to tinside on output than on input.
void Gyoto::Worldline::getCartesian ( double const *const  dates,
size_t const  n_dates,
double *const  x,
double *const  y,
double *const  z,
double *const  xprime = NULL,
double *const  yprime = NULL,
double *const  zprime = NULL 
)
inherited

Get the 6 Cartesian coordinates for specific dates.

The 6 coordinates (x, y, z, dx/dt, dy/dt, dz/dt) will be computed using the integrator and interpolated if necessary, so they will be as accurate as possible. Transforming to Cartesian coordinates is not necessarily meaningful.

Parameters
[in]datesList of dates for which the coordinates are to be computed;
[in]n_datesNumber of dates to compute ;
[out]x,y,z,xprime,yprime,zprimeArrays in which to store the result. These pointer may be set to NULL to retrieve only part of the information. Else, they must be pre-allocated.

Reimplemented in Gyoto::Astrobj::Star.

void Gyoto::Worldline::getCoord ( double const *const  dates,
size_t const  n_dates,
double *const  x1dest,
double *const  x2dest,
double *const  x3dest,
double *const  x0dot = NULL,
double *const  x1dot = NULL,
double *const  x2dot = NULL,
double *const  x3dot = NULL 
)
inherited

Get 8-coordinates for specific dates.

The coordinates will be computed using the integrator, so they will be as accurate as possible. Some heuristics are used to speed up the process and it is presumably faster to call this routine with a sorted list of dates. The line will be integrated further as required. An error will be thrown if it is not possible to reach a certain date.

Parameters
datesthe list of dates for which the coordinates are to be computed;
n_datesthe number of dates to compute ;
x1dest,x2dest,x3dest,x0dot,x1dot,x2dot,x3dotarrays in which to store the result. These pointer may be set to NULL to retrieve only part of the information. They must be pre-allocated.
void Gyoto::Worldline::getCoord ( double *  x0,
double *  x1,
double *  x2,
double *  x3 
) const
inherited

Get all computed positions.

Get all the pre-computed 8 coordinates (e.g. thanks to a prior call to xFill()) of this worldline.

double const* Gyoto::Worldline::getCst ( ) const
inherited

Returns the worldline's cst of motion (if any)

Return pointer to array holding the previously set Metric-specific constants of motion

double Gyoto::Photon::getTransmission ( size_t  i) const
inherited

Get transmission.

Get either Photon::transmission_freqobs_ (with i=-1) or Photon::transmission_[i].

Parameters
ichannel number of the requested frequency, -1 for Photon::freq_obs_.
double const* Gyoto::Photon::getTransmission ( ) const
inherited

Get Photon::transmission_.

getTansmission()[i] == getTransmission(size_t i)

double Gyoto::Photon::getTransmissionMax ( ) const
inherited

Get maximum transmission;.

Get current maximum of all the transmissions, Photon::transmission_freqobs_ or one elements of the Photon::transmission_ array.

int Gyoto::Photon::hit ( Astrobj::Properties data = NULL)
inherited

Integrate the geodesic.

Parameters
[in,out]dataOptional Astrobj::Properties to fill with observational quantities.
Returns
1 if object was hit, else 0.
void Gyoto::Worldline::setCst ( double const *  cst,
size_t const  ncsts 
)
inherited

Set Metric-specific constants of motion.

The will (re)allocate Worldline::cst_, copy cst into it, and set Worldline::cst_n_.

virtual void Gyoto::Worldline::setInitCoord ( double  pos[4],
double  vel[3],
int  dir = 1 
)
virtualinherited

Set initial coordinate.

Parameters
posinitial 4-position
velinitial 3-velocity
dirdirection of integration
void Gyoto::Photon::setInitialCondition ( SmartPointer< Metric::Generic gg,
SmartPointer< Astrobj::Generic obj,
const double  coord[8] 
)
inherited

Set or re-set the initial condition prior to integration.

Set initial condition for this Photon :

Parameters
ggGyoto::SmartPointer to the Gyoto::Metric in this universe;
objGyoto::SmartPointer to the target Gyoto::Astrobj;
coord8-element array containing the initial condition, i.e. the 4-position and the 4-velocity of the Photon at the receiving end;
void Gyoto::Photon::setInitialCondition ( SmartPointer< Metric::Generic gg,
SmartPointer< Astrobj::Generic obj,
SmartPointer< Screen screen,
double  d_alpha,
double  d_delta 
)
inherited

Set or re-set the initial condition prior to integration.

Set initial condition for this Photon :

Parameters
ggGyoto::SmartPointer to the Gyoto::Metric in this universe;
objGyoto::SmartPointer to the target Gyoto::Astrobj;
screenObserver's screen;
d_alphaDirection of arrival (RA offset) in radians;
d_deltaDirection of arrival (Dec offset) in radians.
void Gyoto::Worldline::setInitialCondition ( SmartPointer< Metric::Generic gg,
const double  coord[8],
const int  dir 
)
inherited

Set or re-set the initial condition prior to integration.

Parameters
ggGyoto::SmartPointer to the Gyoto::Metric in this universe;
coord8 element array containing the initial condition, i.e. the 4-position and the 4-velocity of the Photon at the receiving end;
dirdirection: 1 for future, -1 for past.
virtual int Gyoto::Worldline::setParameter ( std::string  name,
std::string  content,
std::string  unit 
)
virtualinherited

Set parameter by name.

Assume MyKind is a subclass of Worldline which has two members (a string StringMember and a double DoubleMember):

int MyKind::setParameter(std::string name,
std::string content,
std::string unit) {
if (name=="StringMember") setStringMember(content);
else if (name=="DoubleMember") setDoubleMember(atof(content.c_str()),
unit);
else return Worldline::setParameter(name, content, unit);
return 0;
}
Parameters
nameXML name of the parameter
contentstring representation of the value
unitstring representation of the unit
Returns
0 if this parameter is known, 1 if it is not.

Reimplemented in Gyoto::Astrobj::Star.

virtual void Gyoto::Worldline::tell ( Gyoto::Hook::Teller msg)
protectedvirtualinherited

This is how a Teller tells.

A teller will basically call listener->tell(this).

Parameters
msgTeller* the Teller who is telling... Useful if the Listener listens to several Tellers.

Reimplemented from Gyoto::Hook::Listener.

void Gyoto::Worldline::xAllocate ( )
protectedinherited

Allocate x0, x1 etc. with default size.

The default size is GYOTO_DEFAULT_X_SIZE

void Gyoto::Worldline::xAllocate ( size_t  size)
protectedinherited

Allocate x0, x1 etc. with a specified size.

Parameters
size: number of cells in each array x0, x1 etc.
size_t Gyoto::Worldline::xExpand ( int  dir)
protectedinherited

Expand x0, x1 etc... to hold more elements.

Double the size of arrays x0, x1 etc. and copy old version of the array in the first half if dir =1 and in the second half if dir =-1.

Parameters
dir: 1 to expand after last element, -1 to expand before first element
Returns
ind : if dir=1, new index of old last element, if dir=-1, new index of old first element

Member Data Documentation

double Gyoto::Photon::freq_obs_
protectedinherited

Photon's frequency in observer's frame.

In Hz, for quantity Emission

SmartPointer<Gyoto::Astrobj::Generic> Gyoto::Photon::object_
protectedinherited

The astronomical target.

The (only) possible origin for this Photon.

SmartPointer<Spectrometer::Generic> Gyoto::Photon::spectro_
protectedinherited

Observer's spectrometer.

Conveying observation frequencies for quantities Spectrum and BinSpectrum.

double* Gyoto::Photon::transmission_
protectedinherited

Integrated optical transmissions.

For each frequency in Photon::spectro_->getMidpoints(), between current position and observer.

double Gyoto::Photon::transmission_freqobs_
protectedinherited

Integrated optical transmission.

At Photon::freq_obs_, between current position and observer.


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