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Gyoto::Metric::Generic Class Reference

Base class for metrics. More...

#include <GyotoMetric.h>

Inheritance diagram for Gyoto::Metric::Generic:
Gyoto::SmartPointee Gyoto::Object Gyoto::Hook::Teller Gyoto::Metric::Hayward Gyoto::Metric::KerrBL Gyoto::Metric::KerrKS Gyoto::Metric::Minkowski Gyoto::Metric::NumericalMetricLorene Gyoto::Metric::Python Gyoto::Metric::RezzollaZhidenko Gyoto::Metric::RotStar3_1

Public Types

typedef Gyoto::SmartPointer< Gyoto::SmartPointeeSubcontractor_t(Gyoto::FactoryMessenger *, std::vector< std::string > const &)
 A subcontractor builds an object upon order from the Factory. More...
 

Public Member Functions

virtual Property const * getProperties () const
 Get list of properties. More...
 
const std::string kind () const
 Get kind_.
 
int getRefCount ()
 
 Generic (const int coordkind, const std::string &name)
 Constructor setting Generic::coordkind_ and kind_.
 
 Generic (Generic const &o)
 Copy constructor.
 
virtual ~Generic ()
 Destructor.
 
virtual Genericclone () const
 Virtual copy constructor. More...
 
void mass (const double)
 Set mass used in unitLength()
 
void mass (const double, const std::string &unit)
 Set mass used in unitLength()
 
int coordKind () const
 Get coordinate kind.
 
double mass () const
 Get mass used in unitLength()
 
double mass (const std::string &unit) const
 Get mass used in unitLength()
 
double unitLength () const
 M * G / c^2, M is in kg, unitLength in meters. More...
 
double unitLength (const std::string &unit) const
 unitLength expressed in specified unit
 
virtual double getRmb () const
 
virtual double getRms () const
 
virtual double getSpecificAngularMomentum (double rr) const
 
virtual double getPotential (double const pos[4], double l_cst) const
 
double deltaMin () const
 
void deltaMin (double h1)
 
double deltaMax () const
 
virtual double deltaMax (double const pos[8], double delta_max_external) const
 
void deltaMax (double h1)
 
double deltaMaxOverR () const
 Get delta_max_over_r_.
 
void deltaMaxOverR (double t)
 Set delta_max_over_r_.
 
bool keplerian () const
 Get keplerian_.
 
void keplerian (bool)
 Set keplerian_.
 
virtual void cartesianVelocity (double const coord[8], double vel[3])
 Compute xprime, yprime and zprime from 8-coordinates.
 
virtual double SysPrimeToTdot (const double coord[4], const double v[3]) const
 Compute tdot as a function of dr/dt, dtheta/dt and dphi/dt. Everything is in geometrical units. More...
 
virtual void circularVelocity (double const pos[4], double vel[4], double dir=1.) const
 Yield circular velocity at a given position. More...
 
virtual void zamoVelocity (double const pos[4], double vel[4]) const
 Yield ZAMO velocity at a given position. More...
 
virtual void nullifyCoord (double coord[8]) const
 Set tdot (coord[4]) such that coord is light-like. Everything is in geometrical units. More...
 
virtual void nullifyCoord (double coord[8], double &tdot2) const
 Set tdot (coord[4]) such that coord is light-like and return other possible tdot. More...
 
virtual void normalizeFourVel (double coord[8]) const
 Normalize fourvelvel to -1. More...
 
virtual void normalizeFourVel (double const pos[4], double fourvel[4]) const
 Normalize fourvelvel to -1. More...
 
virtual double ScalarProd (const double pos[4], const double u1[4], const double u2[4]) const
 Scalar product. More...
 
double norm (const double pos[4], const double u1[4]) const
 Scalar product. More...
 
void multiplyFourVect (double vect[4], double a) const
 multiply vector by scalar
 
void addFourVect (double u1[4], double const u2[4]) const
 add second vector to first one
 
void projectFourVect (double const pos[4], double u1[4], double const u2[4]) const
 project u1 orthogonally to u2 at pos
 
void dualOneForm (double const IN_ARRAY1_1[4], double const IN_ARRAY1_2[4], double ARGOUT_ARRAY1[4]) const
 Computes dual 1-form Compute the dual 1-form of 4-vector. More...
 
virtual void observerTetrad (obskind_t obskind, double const pos[4], double fourvel[4], double screen1[4], double screen2[4], double screen3[4]) const
 Computes the orthonormal local tetrad of the observer. More...
 
virtual void observerTetrad (double const pos[4], double fourvel[4], double screen1[4], double screen2[4], double screen3[4]) const
 Computes the orthonormal local tetrad of the observer. More...
 
void GramSchmidt (double const pos[4], double u0[4], double u1[4], double u2[4], double u3[4]) const
 Apply Gram-Schmidt orthonormalization to a basis. More...
 
virtual double gmunu (double const x[4], int mu, int nu) const
 Metric coefficients. More...
 
virtual void gmunu (double g[4][4], double const pos[4]) const
 Metric coefficients. More...
 
virtual double christoffel (const double coord[4], const int alpha, const int mu, const int nu) const
 Chistoffel symbol. More...
 
virtual int christoffel (double dst[4][4][4], const double coord[4]) const
 Chistoffel symbol. More...
 
virtual int myrk4 (Worldline *line, state_t const &coord, double h, state_t &res) const
 RK4 integrator. More...
 
virtual int myrk4 (Worldline *line, const double coord[8], double h, double res[8]) const =delete
 Obsolete, update your code.
 
virtual int myrk4_adaptive (Gyoto::Worldline *line, state_t const &coord, double lastnorm, double normref, state_t &coordnew, double h0, double &h1, double deltamax=GYOTO_DEFAULT_DELTA_MAX) const
 RK4 integrator with adaptive step. More...
 
virtual int myrk4_adaptive (Gyoto::Worldline *line, const double coord[8], double lastnorm, double normref, double coordnew[8], double h0, double &h1, double deltamax=GYOTO_DEFAULT_DELTA_MAX) const =delete
 Obsolete, update your code.
 
virtual int isStopCondition (double const coord[8]) const
 Check whether integration should stop. More...
 
virtual int diff (state_t const &x, state_t &dxdt) const
 F function such as dx/dt=F(x,cst) More...
 
virtual int diff (const double y[8], double res[8]) const =delete
 Obsolete, update your code.
 
virtual void setParticleProperties (Gyoto::Worldline *line, double const coord[8]) const
 Set Metric-specific constants of motion. Used e.g. in KerrBL. More...
 
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.
 
virtual bool isThreadSafe () const
 Whether this class is thread-safe. More...
 
void set (Property const &p, Value val)
 Set Value of a Property.
 
void set (Property const &p, Value val, std::string const &unit)
 Set Value (expressed in unit) of a Property.
 
void set (std::string const &pname, Value val)
 Set Value of a Property.
 
void set (std::string const &pname, Value val, std::string const &unit)
 Set Value (expressed in unit) of a Property.
 
Value get (Property const &p) const
 Get Value of a Property.
 
Value get (std::string const &pname) const
 Get Value of a Property.
 
Value get (Property const &p, std::string const &unit) const
 Get Value of a Property, converted to unit.
 
Value get (std::string const &pname, std::string const &unit) const
 Get Value of a Property, converted to unit.
 
Property const * property (std::string const pname) const
 Find property by name. More...
 
virtual void fillProperty (Gyoto::FactoryMessenger *fmp, Property const &p) const
 Output a single Property to XML. More...
 
virtual void fillElement (Gyoto::FactoryMessenger *fmp) const
 Fill the XML element for this Object. More...
 
virtual void setParameters (Gyoto::FactoryMessenger *fmp)
 Main loop for parsing Properties from XML description. More...
 
virtual int setParameter (std::string name, std::string content, std::string unit)
 Set parameter by name. More...
 
virtual void setParameter (Gyoto::Property const &p, std::string const &name, std::string const &content, std::string const &unit)
 Set parameter by Property (and name) More...
 
std::string describeProperty (Gyoto::Property const &p) const
 Format desrciption for a property. More...
 
void help () const
 Print (to stdout) some help on this class. More...
 
virtual void hook (Listener *listener)
 Start listening. More...
 
virtual void unhook (Listener *listener)
 Stop listening. More...
 

Static Public Attributes

static GYOTO_OBJECT Property const properties []
 

Protected Member Functions

void kind (const std::string)
 Set kind_. More...
 
void coordKind (int coordkind)
 Set coordkind_. More...
 
virtual void tellListeners ()
 Call tell() on each hooked Listener. More...
 

Protected Attributes

double delta_min_
 Minimum integration step for the adaptive integrator.
 
double delta_max_
 Maximum integration step for the adaptive integrator.
 
double delta_max_over_r_
 Numerical tuning parameter. More...
 
bool keplerian_
 1 if circularVelocity should return the Newtonian Keplerian velocity, in r^-3/2
 
std::string kind_
 The "kind" that is output in the XML entity. More...
 
std::vector< std::string > plugins_
 The plug-ins that needs to be loaded to access this instance's class. More...
 

Private Attributes

double mass_
 Mass yielding geometrical unit (in kg).
 
int coordkind_
 Kind of coordinates (cartesian-like, spherical-like, unspecified)
 
int refCount
 Reference counter.
 
pthread_mutex_t mutex_
 A mutex. More...
 
ListenerItemlisteners_
 Linked list of Listener items.
 

Friends

class Gyoto::SmartPointer< Gyoto::Metric::Generic >
 

Detailed Description

Base class for metrics.

Example: class Gyoto::Metric::KerrBL

See Gyoto::Metric for an introduction.

Member Typedef Documentation

◆ Subcontractor_t

typedef Gyoto::SmartPointer< Gyoto::SmartPointee > Gyoto::SmartPointee::Subcontractor_t(Gyoto::FactoryMessenger *, std::vector< std::string > const &)
inherited

A subcontractor builds an object upon order from the Factory.

Various classes need to provide a subcontractor to be able to instantiate 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

◆ christoffel() [1/2]

virtual double Gyoto::Metric::Generic::christoffel ( const double  coord[4],
const int  alpha,
const int  mu,
const int  nu 
) const
virtual

Chistoffel symbol.

Value of Christoffel symbol Γαμν at point (x1, x2, x3).

Reimplemented in Gyoto::Metric::Hayward, Gyoto::Metric::KerrBL, Gyoto::Metric::KerrKS, Gyoto::Metric::Minkowski, and Gyoto::Metric::NumericalMetricLorene.

◆ christoffel() [2/2]

virtual int Gyoto::Metric::Generic::christoffel ( double  dst[4][4][4],
const double  coord[4] 
) const
virtual

Chistoffel symbol.

Value of Christoffel symbol Γαμν at point (x1, x2, x3).

Returns
1 on error, 0 otherwise

Reimplemented in Gyoto::Metric::Hayward, Gyoto::Metric::KerrBL, Gyoto::Metric::KerrKS, Gyoto::Metric::NumericalMetricLorene, Gyoto::Metric::Hayward, Gyoto::Metric::KerrBL, Gyoto::Metric::KerrKS, and Gyoto::Metric::Minkowski.

◆ circularVelocity()

virtual void Gyoto::Metric::Generic::circularVelocity ( double const  pos[4],
double  vel[4],
double  dir = 1. 
) const
virtual

Yield circular velocity at a given position.

Give the velocity of a massive particle in circular orbit at the given position projected onto the equatorial plane. Such a velocity may not exist everywhere (or anywhere) for a given metric. This method is intended to be used by Astrobj classes such as Torus or ThinDisk.

If keplerian_ is set to true, this method should return the Keplerian velcity instead (derived classes should ensure this, see KerrBL::circularVelocity() for instance).

The default implementation throws an error if keplerian_ is set to false.

Parameters
posinput: position,
veloutput: velocity,
dir1 for corotating, -1 for counterrotating.

Reimplemented in Gyoto::Metric::ChernSimons, Gyoto::Metric::KerrBL, Gyoto::Metric::KerrKS, and Gyoto::Metric::RezzollaZhidenko.

◆ clone()

virtual Generic * Gyoto::Metric::Generic::clone ( ) const
virtual

◆ coordKind()

void Gyoto::Metric::Generic::coordKind ( int  coordkind)
protected

Set coordkind_.

coordkind(int coordkind) is protected because, for most Metrics, it should not be changed in runtime. Set coordinate kind

◆ deltaMax() [1/3]

double Gyoto::Metric::Generic::deltaMax ( ) const

Get delta_max_

◆ deltaMax() [2/3]

virtual double Gyoto::Metric::Generic::deltaMax ( double const  pos[8],
double  delta_max_external 
) const
virtual

Get delta max at a given position

Parameters
pos4-position
[optional]delta_max_external external constraint on delta_max
Returns
the smallest value between delta_max_, delta_max_external, and R*delta_max_over_r_ where R is pos[1] in spherical coordinates and max(x1, x2, x3) in Cartesian coordinates.

◆ deltaMax() [3/3]

void Gyoto::Metric::Generic::deltaMax ( double  h1)

Set delta_max_

◆ deltaMin() [1/2]

double Gyoto::Metric::Generic::deltaMin ( ) const

Get delta_min_

◆ deltaMin() [2/2]

void Gyoto::Metric::Generic::deltaMin ( double  h1)

Set delta_min_

◆ describeProperty()

std::string Gyoto::Object::describeProperty ( Gyoto::Property const &  p) const
inherited

Format desrciption for a property.

Returns a string containing the name(s) and type of the property, as well as whether it supports unit.

◆ diff()

virtual int Gyoto::Metric::Generic::diff ( state_t const &  x,
state_t &  dxdt 
) const
virtual

F function such as dx/dt=F(x,cst)

Reimplemented in Gyoto::Metric::NumericalMetricLorene, and Gyoto::Metric::RotStar3_1.

◆ dualOneForm()

void Gyoto::Metric::Generic::dualOneForm ( double const  IN_ARRAY1_1[4],
double const  IN_ARRAY1_2[4],
double  ARGOUT_ARRAY1[4] 
) const

Computes dual 1-form Compute the dual 1-form of 4-vector.

Parameters
IN_ARRAY1_14-position;
IN_ARRAY1_2quadrivector;
[out]ARGOUT_ARRAY3output 1-form

◆ fillElement()

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

Fill the XML element for this Object.

The base implementation simply calls fillProperty() for each Property defined for the Object.

Derived classes should avoid overriding fillElement(). It may make sense occasionally, e.g. to make sure that the metric is output first.

To customize how a given Property is rendered, it is better to override fillProperty().

If this method is overridden, the implementation should in general call fillElement() on the direct base.

Reimplemented in Gyoto::Astrobj::Complex, Gyoto::Spectrometer::Complex, and Gyoto::Scenery.

◆ fillProperty()

virtual void Gyoto::Object::fillProperty ( Gyoto::FactoryMessenger fmp,
Property const &  p 
) const
virtualinherited

Output a single Property to XML.

The base implementation decides what to do based on the p.type. The format matches how setParameters() an setParameter() would interpret the XML descition.

Overriding this method should be avoided, but makes sense in some cases (for instance Screen::fillProperty() selects a different unit for Distance based on its magnitude, so that stellar sizes are expressed in solar radii while smaller sizes can be expressed in meters and larger sizes in parsecs).

Overriding implementation should fall-back on calling the implementation in the direct parent class:

class A: public Object {};
class B: public A {
using B::setParameter;
Property const &p) const ;
};
void B::fillProperty(Gyoto::FactoryMessenger *fmp,
Property const &p) const {
if (name=="Duff") fmp->doSomething();
else A::fillProperty(fmp, p);
}
Factory / SmartPointee::Subcontractor_t interface.
Definition: GyotoFactoryMessenger.h:92
Object with properties.
Definition: GyotoObject.h:152
virtual void fillProperty(Gyoto::FactoryMessenger *fmp, Property const &p) const
Output a single Property to XML.
Property that can be set and got using standard methods.
Definition: GyotoProperty.h:608

Reimplemented in Gyoto::Scenery, Gyoto::Astrobj::DirectionalDisk, Gyoto::Astrobj::Disk3D, Gyoto::Astrobj::EquatorialHotSpot, Gyoto::Astrobj::NeutronStarModelAtmosphere, Gyoto::Astrobj::PatternDisk, Gyoto::Astrobj::PolishDoughnut, Gyoto::Screen, Gyoto::Astrobj::Star, Gyoto::Spectrometer::Uniform, and Gyoto::Astrobj::XillverReflection.

◆ getPotential()

virtual double Gyoto::Metric::Generic::getPotential ( double const  pos[4],
double  l_cst 
) const
virtual

Returns potential W=-ln(|u_t|) for a cst specific angular momentum l_cst Should be implemented in derived classes if useful If called on the base class, returns an error

Reimplemented in Gyoto::Metric::Hayward, Gyoto::Metric::KerrBL, Gyoto::Metric::NumericalMetricLorene, and Gyoto::Metric::RezzollaZhidenko.

◆ getProperties()

virtual Property const * Gyoto::Metric::Generic::getProperties ( ) const
virtual

◆ getRmb()

virtual double Gyoto::Metric::Generic::getRmb ( ) const
virtual

Returns the marginally bound radius Should be implemented in derived classes if useful If called on the base class, returns an error

Reimplemented in Gyoto::Metric::Hayward, Gyoto::Metric::KerrBL, Gyoto::Metric::NumericalMetricLorene, and Gyoto::Metric::RezzollaZhidenko.

◆ getRms()

virtual double Gyoto::Metric::Generic::getRms ( ) const
virtual

Returns the marginally stable (ISCO) radius Should be implemented in derived classes if useful If called on the base class, returns an error

Reimplemented in Gyoto::Metric::Hayward, Gyoto::Metric::KerrBL, Gyoto::Metric::NumericalMetricLorene, and Gyoto::Metric::RezzollaZhidenko.

◆ getSpecificAngularMomentum()

virtual double Gyoto::Metric::Generic::getSpecificAngularMomentum ( double  rr) const
virtual

Returns the specific angular momentum l=-u_phi/u_t Should be implemented in derived classes if useful If called on the base class, returns an error

Reimplemented in Gyoto::Metric::Hayward, Gyoto::Metric::KerrBL, Gyoto::Metric::NumericalMetricLorene, and Gyoto::Metric::RezzollaZhidenko.

◆ gmunu() [1/2]

virtual double Gyoto::Metric::Generic::gmunu ( double const  x[4],
int  mu,
int  nu 
) const
virtual

Metric coefficients.

The default implementation calls Metric:: gmunu(double g[4][4], const double * pos) const

Parameters
x4-position at which to compute the coefficient;
mu1st index of coefficient, 0≤μ≤3;
nu2nd index of coefficient, 0≤ν≤3;
Returns
Metric coefficient gμ,ν at point x

Reimplemented in Gyoto::Metric::KerrKS, Gyoto::Metric::Minkowski, Gyoto::Metric::NumericalMetricLorene, and Gyoto::Metric::NumericalMetricLorene.

◆ gmunu() [2/2]

virtual void Gyoto::Metric::Generic::gmunu ( double  g[4][4],
double const  pos[4] 
) const
virtual

Metric coefficients.

The default implementation calls double gmunu(const double * x, int mu, int nu) const.

Parameters
[out]g4x4 array to store the coeefficients
[in]x4-position at which to compute the coefficients;
Returns
Metric coefficient gμ,ν at point x

Reimplemented in Gyoto::Metric::KerrKS, Gyoto::Metric::Minkowski, and Gyoto::Metric::NumericalMetricLorene.

◆ GramSchmidt()

void Gyoto::Metric::Generic::GramSchmidt ( double const  pos[4],
double  u0[4],
double  u1[4],
double  u2[4],
double  u3[4] 
) const

Apply Gram-Schmidt orthonormalization to a basis.

On input, u0 to u3 must be four non-zero norm, independent 4-vectors. On output, they will form an orthonormal basis.

Parameters
[in]posposition,
[in,out]u0basis vector
[in,out]u1basis vector
[in,out]u2basis vector
[in,out]u3basis vector

◆ help()

void Gyoto::Object::help ( ) const
inherited

Print (to stdout) some help on this class.

Describe all properties that this instance supports.

◆ hook()

virtual void Gyoto::Hook::Teller::hook ( Listener listener)
virtualinherited

Start listening.

Use from a Hook::Listener object method:

teller->hook(this)

where "this" is a Listener and "teller" is a Teller.

Use unhook() later to stop listening to a given Teller.

Parameters
listenerpointer to the new listener

◆ isStopCondition()

virtual int Gyoto::Metric::Generic::isStopCondition ( double const  coord[8]) const
virtual

Check whether integration should stop.

The integrating loop will ask this the Metric through this method whether or not it is happy to continue the integration. Typically, the Metric should answer 0 when everything is fine, 1 when too close to the event horizon, inside the BH...

Parameters
coord8-coordinate vector to check.

◆ isThreadSafe()

virtual bool Gyoto::Object::isThreadSafe ( ) const
virtualinherited

Whether this class is thread-safe.

Return True if this object is thread-safe, i.e. if an instance and its clone can be used in parallel threads (in the context of Scenery::raytrace()). Known objects which are not thread-safe include Lorene metrics and everything from the Python plug-in.

The default implementation considers that the class itself is thread safe and recurses into the declared properties to check whether they are safe too. Classes that abide to the Object/Property paradigm and are themselves thread-safe have nothing special to do.

Objects that clone children in their copy constructor that are not declared as properties must take these children into account.

Classes that are never thread-safe must declare it. It acn be easily done using GYOTO_OBJECT_THREAD_SAFETY in the class declaration and GYOTO_PROPERTY_THREAD_UNSAFE in the class definition.

◆ kind()

void Gyoto::Metric::Generic::kind ( const std::string  )
protected

Set kind_.

kind(const std::string) is protected because, for most Metrics, it should not be changed in runtime. Set kind_

◆ myrk4()

virtual int Gyoto::Metric::Generic::myrk4 ( Worldline line,
state_t const &  coord,
double  h,
state_t &  res 
) const
virtual

RK4 integrator.

Reimplemented in Gyoto::Metric::KerrBL, and Gyoto::Metric::NumericalMetricLorene.

◆ myrk4_adaptive()

virtual int Gyoto::Metric::Generic::myrk4_adaptive ( Gyoto::Worldline line,
state_t const &  coord,
double  lastnorm,
double  normref,
state_t &  coordnew,
double  h0,
double &  h1,
double  deltamax = GYOTO_DEFAULT_DELTA_MAX 
) const
virtual

RK4 integrator with adaptive step.

Reimplemented in Gyoto::Metric::KerrBL, Gyoto::Metric::NumericalMetricLorene, and Gyoto::Metric::RotStar3_1.

◆ norm()

double Gyoto::Metric::Generic::norm ( const double  pos[4],
const double  u1[4] 
) const

Scalar product.

Compute the norm of the quadrivector u1 in this Metric, at point pos expressed in coordinate system sys.

Parameters
[in]pos4-position;
[in]u1quadrivector;
Returns
||u1||

◆ normalizeFourVel() [1/2]

virtual void Gyoto::Metric::Generic::normalizeFourVel ( double const  pos[4],
double  fourvel[4] 
) const
virtual

Normalize fourvelvel to -1.

First computes threevel as xiprime=xidot/x0dot for i in {1, 2, 3}, then computes x0dot using SyPrimeToTdot, then computes again xidot as xidot=xiprime*x0dot.

Parameters
[in]pos4-position;
[in,out]fourvel4-velocity, will be renormalized.

◆ normalizeFourVel() [2/2]

virtual void Gyoto::Metric::Generic::normalizeFourVel ( double  coord[8]) const
virtual

Normalize fourvelvel to -1.

First computes threevel as xiprime=xidot/x0dot for i in {1, 2, 3}, then computes x0dot using SyPrimeToTdot, then computes again xidot as xidot=xiprime*x0dot.

Parameters
[in,out]coord8-position, coord[4-7] will be set according to the other elements;

◆ nullifyCoord() [1/2]

virtual void Gyoto::Metric::Generic::nullifyCoord ( double  coord[8]) const
virtual

Set tdot (coord[4]) such that coord is light-like. Everything is in geometrical units.

Set coord[4] so that the 4-velocity coord[4:7] is lightlike, i.e. of norm 0. There may be up to two solutions. coord[4] is set to the hightest. The lowest can be retrieved using nullifyCoord(double coord[8], double& tdot2) const. Everything is expressed in geometrical units.

Parameters
[in,out]coord8-position, coord[4] will be set according to the other elements;

Reimplemented in Gyoto::Metric::KerrBL.

◆ nullifyCoord() [2/2]

virtual void Gyoto::Metric::Generic::nullifyCoord ( double  coord[8],
double &  tdot2 
) const
virtual

Set tdot (coord[4]) such that coord is light-like and return other possible tdot.

Set coord[4] so that the 4-velocity coord[4:7] is lightlike, i.e. of norm 0. There may be up to two solutions. coord[4] is set to the hightest. The lowest can be retrieved in tdot2. Everything is expressed in geometrical units.

Parameters
[in,out]coord8-position, coord[4] will be set according to the other elements;
[out]tdot2will be set to the smallest solution

Reimplemented in Gyoto::Metric::KerrBL.

◆ observerTetrad() [1/2]

virtual void Gyoto::Metric::Generic::observerTetrad ( double const  pos[4],
double  fourvel[4],
double  screen1[4],
double  screen2[4],
double  screen3[4] 
) const
virtual

Computes the orthonormal local tetrad of the observer.

Parameters
[in]posposition,
[in]fourvelobserver 4-velocity (norm -1)
[out]screen1first vector in the screen plane
[out]screen2second vector in the screen plane
[out]screen3vector normal to the screen

Reimplemented in Gyoto::Metric::KerrBL.

◆ observerTetrad() [2/2]

virtual void Gyoto::Metric::Generic::observerTetrad ( obskind_t  obskind,
double const  pos[4],
double  fourvel[4],
double  screen1[4],
double  screen2[4],
double  screen3[4] 
) const
virtual

Computes the orthonormal local tetrad of the observer.

Parameters
obskindinput: kind of observer (eg: "ZAMO","KeplerianObserver"...)
posinput: position,
fourveloutput: observer 4-velocity (norm -1)
screen1output: first vector in the screen plane
screen2output: second vector in the screen plane
screen3output: vector normal to the screen

Reimplemented in Gyoto::Metric::Minkowski.

◆ property()

Property const * Gyoto::Object::property ( std::string const  pname) const
inherited

Find property by name.

Look into the Property list for a Property whose name (or name_false, for a boolean Property) is pname. Return a const pointer to the first such property found, or NULL if none is found.

◆ ScalarProd()

virtual double Gyoto::Metric::Generic::ScalarProd ( const double  pos[4],
const double  u1[4],
const double  u2[4] 
) const
virtual

Scalar product.

Compute the scalarproduct of the two quadrivectors u1 and u2 in this Metric, at point pos expressed in coordinate system sys.

Parameters
pos4-position;
u11st quadrivector;
u22nd quadrivector;
Returns
u1*u2

Reimplemented in Gyoto::Metric::Hayward, Gyoto::Metric::KerrBL, and Gyoto::Metric::RotStar3_1.

◆ setParameter() [1/2]

virtual void Gyoto::Object::setParameter ( Gyoto::Property const &  p,
std::string const &  name,
std::string const &  content,
std::string const &  unit 
)
virtualinherited

Set parameter by Property (and name)

This function is used when parsing an XML description, if Property (p) of this name is found (i.e. either p.name or p.name_false is equal to name). Implementation should fall-back on calling the direct's parent implementation:

class A: public Object {};
class B: public A {
using B::setParameter;
virtual void setParameter(Gyoto::Property const &p,
std::string name,
std::string content,
std::string unit);
};
void B::setParameter(Gyoto::Property const &p,
std::string name,
std::string content,
std::string unit) {
if (name=="Duff") doSomething(content, unit);
else A::setParameter(p, name, content, unit);
}
virtual int setParameter(std::string name, std::string content, std::string unit)
Set parameter by name.
Parameters
pProperty that matches name (p.name == name or p.name_false == name)
nameXML name of the parameter (XML entity)
contentstring representation of the value
unitstring representation of the unit

Reimplemented in Gyoto::Astrobj::PolishDoughnut.

◆ setParameter() [2/2]

virtual int Gyoto::Object::setParameter ( std::string  name,
std::string  content,
std::string  unit 
)
virtualinherited

Set parameter by name.

This function is used when parsing an XML description, if no Property of this name is found. Overriding implementation should fall-back on calling the direct's parent implementation:

class A: public Object {};
class B: public A {
using B::setParameter;
virtual int setParameter(std::string name,
std::string content,
std::string unit);
};
int B::setParameter(std::string name,
std::string content,
std::string unit) {
if (name=="Duff") doSomething(content, unit);
else return A::setParameter(name, content, unit);
return 0; // name was known
}
Parameters
nameXML name of the parameter (XML entity). This may have a path component, e.g. "Astrobj::Radius", in which case a property named "Astrobj" will be sought in the current object, and setParameter will be called recusrively on this Astrobj with Radius as name.
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::EquatorialHotSpot, Gyoto::Metric::KerrKS, Gyoto::Astrobj::Star, and Gyoto::Metric::RotStar3_1.

◆ setParameters()

virtual void Gyoto::Object::setParameters ( Gyoto::FactoryMessenger fmp)
virtualinherited

Main loop for parsing Properties from XML description.

 This function queries the FactoryMessenger for elements to parse,
 and tries to matche each element to a Property to set it
 accordingly.

 Any class that tries to be buildable from XML must supply a
 subcontractor (for base classes such as Metric, Astrobj, Spectrum
 and Spectrometer, it is done as a template that must be
 specialized for each class).

 This subcontractor typically looks somewhat like this:
SmartPointer<MyKind> gg = new MyKind();
gg -> setParameters(fmp);
return gg;
}
virtual void setParameters(Gyoto::FactoryMessenger *fmp)
Main loop for parsing Properties from XML description.
Pointers performing reference counting.
Definition: GyotoSmartPointer.h:135
SmartPointer< Astrobj::Generic > Subcontractor(FactoryMessenger *fmp, std::vector< std::string > const &plugin)
A template for Subcontractor_t functions.
Definition: GyotoAstrobj.h:76
 Although this is discouraged, it is possible to override the
 following functions to customize how XML entities are parsed:
   - setParameters() if low-level access to the
     FactoryMessenger is required;
   - setParameter(std::string name,
                  std::string content,
                  std::string unit)
     to interpret an entity that does not match a Property
     (e.g. alternative name);
   - setParameter(Gyoto::Property const &p,
                  std::string const &name,
                  std::string const &content,
                  std::string const &unit)
     to change how a Property is interpreted.

Reimplemented in Gyoto::Astrobj::Generic, Gyoto::Astrobj::Complex, Gyoto::Spectrometer::Complex, Gyoto::Astrobj::EquatorialHotSpot, Gyoto::Photon, Gyoto::Astrobj::Star, Gyoto::Spectrometer::Uniform, and Gyoto::Astrobj::OscilTorus.

◆ setParticleProperties()

virtual void Gyoto::Metric::Generic::setParticleProperties ( Gyoto::Worldline line,
double const  coord[8] 
) const
virtual

Set Metric-specific constants of motion. Used e.g. in KerrBL.

Reimplemented in Gyoto::Metric::NumericalMetricLorene.

◆ SysPrimeToTdot()

virtual double Gyoto::Metric::Generic::SysPrimeToTdot ( const double  coord[4],
const double  v[3] 
) const
virtual

Compute tdot as a function of dr/dt, dtheta/dt and dphi/dt. Everything is in geometrical units.

Parameters
coord4-position (geometrical units);
v3-velocity dx1/dx0, dx2/dx0, dx3/dx0;
Returns
tdot = dx0/dtau.

◆ tellListeners()

virtual void Gyoto::Hook::Teller::tellListeners ( )
protectedvirtualinherited

Call tell() on each hooked Listener.

Whenever a Teller mutates, it should warn any Listener hooked to it using tellListeners().

◆ unhook()

virtual void Gyoto::Hook::Teller::unhook ( Listener listener)
virtualinherited

Stop listening.

Use from a Hook::Listener object method:

teller->unhook(this)

where "this" is a Listener, "teller" is a Teller, and "this" has called teller->hook(this) previously.

Parameters
listenerpointer to the listener

◆ unitLength()

double Gyoto::Metric::Generic::unitLength ( ) const

M * G / c^2, M is in kg, unitLength in meters.

Metrics implementations are free to express lengths and distances in whatever unit they see fit (presumably most often geometrical units). This function returns this unit in SI (meters).

◆ zamoVelocity()

virtual void Gyoto::Metric::Generic::zamoVelocity ( double const  pos[4],
double  vel[4] 
) const
virtual

Yield ZAMO velocity at a given position.

Give the velocity of a zero angular momentul observer (whatever is closest to "at rest"). The default implementation simply projects (1, 0, 0, 0) othogonally along ephi and normalizes it, thus ensuring that vel is orthogonal to ephi.

Parameters
posinput: position,
veloutput: velocity,

Reimplemented in Gyoto::Metric::KerrBL.

Member Data Documentation

◆ delta_max_over_r_

double Gyoto::Metric::Generic::delta_max_over_r_
protected

Numerical tuning parameter.

Ensure that delta (the numerical integration step) is never larger than a fraction of the distance between the current location and the center of the coordinate system.

For investigations close to the event horizon, 0.5 is usually fine. If high accuracy is needed long after deflection (weak lensing), then this must be smaller. A good test is to look at a MinDistance map for a FixedStar: it must be smooth.

◆ kind_

std::string Gyoto::Object::kind_
protectedinherited

The "kind" that is output in the XML entity.

E.g. for an Astrobj, fillElement() will ensure

<Astrobj kind="kind_" ...>...</Astrobj>
const std::string kind() const
Get kind_.

is written.

◆ mutex_

pthread_mutex_t Gyoto::SmartPointee::mutex_
privateinherited

A mutex.

When compiled with libpthread

◆ plugins_

std::vector<std::string> Gyoto::Object::plugins_
protectedinherited

The plug-ins that needs to be loaded to access this instance's class.

E.g. for an Astrobj, fillElement() will ensure

<Astrobj ... plugin="plugins_">...</Astrobj>

is written.


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