Gyoto
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Mass-less, spherical object following a timelike geodesic. More...
#include <GyotoStar.h>
Public Member Functions | |
Star (SmartPointer< Metric::Generic > gg, double radius, double pos[4], double v[3]) | |
Standard constructor. | |
Star () | |
Default constructor. | |
Star (const Star &orig) | |
Copy constructor. | |
virtual Star * | clone () const |
"Virtual" copy constructor | |
virtual | ~Star () |
Destructor. | |
virtual std::string | className () const |
"Star" | |
virtual std::string | className_l () const |
"star" | |
virtual void | setMetric (SmartPointer< Metric::Generic >) |
Set metric Smartpointer. | |
virtual SmartPointer < Metric::Generic > | getMetric () const |
Get metric. | |
virtual double | getMass () const |
Return 1. | |
virtual double | getRmax () |
Get maximal distance from center of coordinate system. | |
virtual void | unsetRmax () |
Set rmax_set_ to 0. | |
void | setInitialCondition (double coord[8]) |
Same as Worldline::setInitialCondition(gg, coord, sys,1) | |
virtual void | setInitCoord (double pos[4], double vel[3], int dir=1) |
virtual void | setPosition (double pos[4]) |
virtual void | setVelocity (double vel[3]) |
virtual int | setParameter (std::string name, std::string content) |
Called from setParameters() | |
virtual void | setParameters (FactoryMessenger *fmp) |
virtual void | fillElement (FactoryMessenger *fmp) const |
called from Factory | |
virtual 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) |
Yield the Cartesian coordinates of the center of the sphere. | |
virtual void | getVelocity (double const pos[4], double vel[4]) |
Yield velocity of the center of the sphere. | |
virtual void | setSpectrum (SmartPointer< Spectrum::Generic >) |
Set spectrum_. | |
virtual SmartPointer < Spectrum::Generic > | getSpectrum () const |
Get spectrum_. | |
virtual void | setOpacity (SmartPointer< Spectrum::Generic >) |
Set opacity_. | |
virtual SmartPointer < Spectrum::Generic > | getOpacity () const |
Get opacity_. | |
double | getRadius () const |
Get radius_. | |
void | setRadius (double) |
Set radius_. | |
virtual double | operator() (double const coord[4]) |
Square distance to the center of the sphere. | |
virtual double | operator() (double const data[])=0 |
virtual double | transmission (double nuem, double dsem, double coord[8]) const |
Transmission: exp( {} * dsem ) | |
virtual void | setSafetyValue (double val) |
virtual double | getSafetyValue () const |
virtual int | Impact (Gyoto::Photon *ph, size_t index, Astrobj::Properties *data=NULL) |
does a photon at these coordinates impact the object? | |
virtual double | giveDelta (double coord[8]) |
const std::string | getKind () const |
Get the kind of the Astrobj (e.g. "Star") | |
virtual void | setRmax (double val) |
Set maximal distance from center of coordinate system. | |
void | setFlag_radtransf (int flag) |
Set whether the object is optically thin. | |
int | getFlag_radtransf () const |
Query whether object is optically thin. | |
virtual Quantity_t | getDefaultQuantities () |
virtual void | processHitQuantities (Photon *ph, double *coord_ph_hit, double *coord_obj_hit, double dt, Astrobj::Properties *data) const |
void | checkPhiTheta (double coord[8]) const |
int | getImin () const |
int | getImax () const |
int | getI0 () const |
void | setInitCoord (const double coord[8], int dir=0) |
Set Initial coordinate. | |
void | reset () |
Forget integration, keeping initial contition. | |
void | setDelta (const double delta) |
Set delta. | |
double | getTlim () const |
Get tlim value. | |
void | setTlim (double tlim) |
Set tlim to a given value. | |
double const * | getCst () const |
Returns the worldline's cst of motion (if any) | |
void | setCst (double const *cst, size_t const ncsts) |
void | setInitialCondition (SmartPointer< Metric::Generic > gg, const double coord[8], const int dir) |
Set or re-set the initial condition prior to integration. | |
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) |
void | getCoord (double *x0, double *x1, double *x2, double *x3) const |
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. | |
int | get_nelements () const |
void | get_t (double *dest) const |
void | get_xyz (double *x, double *y, double *z) const |
void | getSkyPos (SmartPointer< Screen > screen, double *dalpha, double *ddellta, double *dD) const |
void | get_dot (double *x0dot, double *x1dot, double *x2dot, double *x3dot) const |
void | get_prime (double *x1prime, double *x2prime, double *x3prime) const |
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. |
Protected Types | |
typedef Gyoto::SmartPointer < Gyoto::SmartPointee > | Subcontractor_t (Gyoto::FactoryMessenger *) |
A subcontractor builds an object upon order from the Factory. |
Protected Member Functions | |
virtual double | emission (double nu_em, double dsem, double cp[8], double co[8]=NULL) const |
Emission is determined by spectrum_ and opacity_. | |
virtual double | integrateEmission (double nu1, double nu2, double dsem, double c_ph[8], double c_obj[8]=NULL) const |
^nu2 I_nu dnu (or j_nu) | |
virtual double | transmission (double nuem, double dsem, double *) const |
Transmission is determined by opacity_. | |
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. | |
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. |
Protected Attributes | |
double | radius_ |
sphere radius | |
SmartPointer< Spectrum::Generic > | spectrum_ |
sphere emission law | |
SmartPointer< Spectrum::Generic > | opacity_ |
if optically thin, opacity law | |
double | critical_value_ |
see operator()(double const coord[4]) const | |
double | safety_value_ |
see operator()(double const coord[4]) const | |
SmartPointer < Gyoto::Metric::Generic > | gg_ |
double | rmax_ |
Maximum distance to the center of the coordinate system. | |
int | rmax_set_ |
Never recompute rmax: it was externally set. | |
const std::string | kind_ |
Kind of object (e.g. "Star"...) | |
int | flag_radtransf_ |
1 if radiative transfer inside Astrobj, else 0 | |
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. | |
double | delta_ |
Initial integrating step ; defaults to 0.01. | |
double | tlim_ |
Minimum time for integration, stop integration if t<tlim ; defaults to 0. | |
double * | cst_ |
Worldline's csts of motion (if any) | |
size_t | cst_n_ |
Number of constants of motion. |
Private Attributes | |
int | wait_pos_ |
Hack in setParameters() | |
double * | init_vel_ |
Hack in setParameters() |
Friends | |
class | Gyoto::SmartPointer< Gyoto::Astrobj::Star > |
Mass-less, spherical object following a timelike geodesic.
Gyoto can compute the Star's orbit in a Gyoto::Metric and perform ray-tracing on this target. The XML description of a Star looks like:
The Metric element can be of any kind. This Metric sets the coordinate system.
The Star is a coordinate sphere of radius Radius in solid motion.
Position sets the initial 4-coordinate of the centre of the sphere. Velocity contains its initial 3-velocity (the time derivatives of the 3 space coordinates).
Like many Astrobj::Generic impementations, a Star can be OpticallyThin or OpticallyThick.
Spectrum and Opacity (if OpticallyThin) are the descriptions of two Gyoto::Spectrum::Generic sub-classes.
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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().
Gyoto::Astrobj::Star::Star | ( | SmartPointer< Metric::Generic > | gg, |
double | radius, | ||
double | pos[4], | ||
double | v[3] | ||
) |
Standard constructor.
Create Star object and set initial condition.
gg,: | Gyoto::SmartPointer to the Gyoto::Metric in this part of the Universe |
radius | star radius |
pos[4] | initial position |
v[3] | initial velocity |
Gyoto::Astrobj::Star::Star | ( | ) |
Default constructor.
Create Star object with undefined initial conditions. One needs to set the coordinate system, the metric, and the initial position and velocity before integrating the orbit. setInititialCondition() can be used for that.
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inherited |
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".
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virtual |
"Virtual" copy constructor
This method must be implemented by the various Astrobj::Generic subclasses in order to support cloning:
Implementing it is very straightforward, as long as the copy constructor Generic(const Generic& ) has been implemented:
Implements Gyoto::Astrobj::Generic.
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virtual |
Yield the Cartesian coordinates of the center of the sphere.
If the coordinate system of the Metric object is spherical, use a trivial conversion.
Implements Gyoto::Astrobj::UniformSphere.
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inherited |
Get 8-coordinates for spcific 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.
dates,: | the list of dates for which the coordinates are to be computed; |
n_dates,: | the number of dates to compute ; |
x*,: | arrays 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. |
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inherited |
Get all the pre-computed 8 coordinates (e.g. thanks to a prior call to xFill()) of this worldline.
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inherited |
Returns the worldline's cst of motion (if any)
Return pointer to array holding the previously set Metric-specific constants of motion
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virtualinherited |
Return a Gyoto::Quantity_t suitable as input to Gyoto::Scenery::setRequestedQuantities() to set de default quantities to compute for this object. The default of these defaults GYOTO_QUANTITY_INTENSITY.
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inherited |
Query whether object is optically thin.
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virtual |
Return 1.
The mass of a Star is always 1. Stars do not perturb the metric. The only relevant point is that Stars are massive particules, their exact mass is of no importance.
Implements Gyoto::Worldline.
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virtual |
Get maximal distance from center of coordinate system.
Get maximal distance from center of coordinate system at which a Photon may hit the object.
Child classes may use the rmax_ member to cache this value.
It can also be set using setRmax(). If setRmax has been used to set rmax_, getRmax() must not recompute it.
Reimplemented from Gyoto::Astrobj::Generic.
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virtualinherited |
Used by Standard::Impact().
Gives the requested integration step delta_t (in coordinate time t) between two neighbooring points along a portion of geodesic inside an astrobj
coord | input coordinate at which delta_t is given |
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virtualinherited |
does a photon at these coordinates impact the object?
Impact() checks whether a Photon impacts the object between two integration steps of the photon's trajectory (those two steps are photon->getCoord(index, coord1) and photon->getCoord(index+1, coord2)). Impact returns 1 if the photon impacts the object between these two steps, else 0. In many cases of geometrically thick obects, the implementation Astrobj::Standard::Impact() will be fine.
Impact will call Generic::processHitQuantities() (which is virtual and may be re-implemented) to compute observable properties on demand: if the data pointer is non-NULL, the object will look in it for pointers to properties which apply to its kind. If a pointer to a property known to this object is present, then the property is computed and store at the pointed-to adress. For instance, all objects know the "intensity" property. If data->intensity != NULL, the instensity is computed and stored in *data->intensity.
If data is non-NULL and only in this case, processHitQuantities() will also call ph->transmit() to update the transmissions of the Photon (see Photon::transmit(size_t, double)). This must not be done if data is NULL (see Astrobj::Complex::Impact() for an explanation).
ph | Gyoto::Photon aimed at the object; |
index | Index of the last photon step; |
data | Pointer to a structure to hold the observables at impact. |
Implements Gyoto::Astrobj::Generic.
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protectedvirtualinherited |
^nu2 I_nu dnu (or j_nu)
Compute the integral of emission() from nu1 to nu2. The default implementation is a numerical integrator which works well enough and is reasonably fast if emission() is a smooth function (i.e. no emission or absorption lines). If possible, it is wise to implement an analytical solution. It is used by processHitQuantities to compute the "BinSpectrum" quantity which is the most physical: it is the only quantity that can be actually measured directly by a real-life instrument.
Reimplemented from Gyoto::Astrobj::Generic.
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virtualinherited |
processHitQuantities fills the requested data in Impact. To use it, you need to call it in the Impact() method for your object in case of hit. It will fill Redshift, Intensity, Spectrum, BinSpectrum and update the Photon's transmission by calling Photon::transmi(), only if data==NULL.
You can overload it for your Astrobj. The generic implementation calls emission(), integrateEmission() and transmission() below.
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inherited |
Set Metric-specific constants of motion
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inherited |
Set whether the object is optically thin.
Set flag indicating that radiative transfer should be integrated, i.e. the object is to be considered optically thin.
flag,: | 1 if optically thin, 0 if optically thick. |
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inherited |
Set or re-set the initial condition prior to integration.
Set initial condition for this Photon :
gg | : Gyoto::SmartPointer to the Gyoto::Metric in this universe; |
coord | : 8 element array containing the initial condition, i.e. the 4-position and the 4-velocity of the Photon at the receiving end; |
sys | : an integer stating in which coordinate system coord is given. |
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virtual |
Called from setParameters()
Assume MyKind is a sublcass of Astrobj::Generic which has towo members (a string StringMember and a double DoubleMember):
If MyKind is not a direct subclass of Generic but is a subclass of e.g. Standard, UniformSphere of ThinDisk, it should call the corresponding setParameter() implementation instead of Generic::setParameter().
name | XML name of the parameter |
content | string representation of the value |
Reimplemented from Gyoto::Astrobj::UniformSphere.
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virtual |
This implementation of UniformSphere::setParameters() uses wait_pos_ and init_vel_ to make sure setVelocity() is called after setPosition().
Reimplemented from Gyoto::Astrobj::UniformSphere.
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virtualinherited |
Set maximal distance from center of coordinate system.
Set maximal distance from center of coordinate system at which a Photon may hit the object.
Side effect: set rmax_set_ to 1.
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virtualinherited |
Transmission: exp( {} * dsem )
transmission() computes the transmission of this fluid element or 0 if optically thick. The default implementation returns 1. (no attenuation) if optically thin, 0. if optically thick.
nuem | frequency in the fluid's frame |
coord | Photon coordinate |
dsem | geometrical length in geometrical units |
Reimplemented in Gyoto::Astrobj::PatternDisk, and Gyoto::Astrobj::Torus.
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virtual |
Set rmax_set_ to 0.
getRmax() will then be free to recompute rmax_. Astrobjs which cache rmax_ may need to update it when unsetRmax() is called.
Reimplemented from Gyoto::Astrobj::Generic.
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protectedinherited |
Allocate x0, x1 etc. with default size.
The default size is GYOTO_DEFAULT_X_SIZE
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protectedinherited |
Allocate x0, x1 etc. with a specified size.
size | : number of cells in each array x0, x1 etc. |
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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.
dir | : 1 to expand after last element, -1 to expand before first element |
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protectedinherited |
The Metric in this end of the Universe
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protectedinherited |
Kind of object (e.g. "Star"...)
The kind should match the name of the class, e.g. "Star" for a Gyoto::Star.
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protectedinherited |
Maximum distance to the center of the coordinate system.
Maximum distance from the center of the coordinate system at which a photon may hit the object. Child classes may choose to update rmax at all time or to use it to cache the value, for instance when getRmax() is called. External classes (Photons in particular) must use getRmax() to access this information.
rmax_set_==1 means that rmax_ was set using setRmax() or the constructor. In this case, getRmax() must always return this value, not recompute it.
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protectedinherited |
Never recompute rmax: it was externally set.
rmax_set_==1 means that rmax_ was set using setRmax() or the constructor. In this case, getRmax() must always return this value, not recompute it.
Use unsetRmax() to reset rmax_set_ to 0.