Gyoto
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Timelike or null geodesics. More...
#include <GyotoWorldline.h>
Classes | |
class | IntegState |
Public Member Functions | |
Worldline () | |
Default constructor. | |
Worldline (const Worldline &) | |
Copy constructor. | |
Worldline (Worldline *orig, size_t i0, int dir, double step_max) | |
Refine constructor. More... | |
virtual | ~Worldline () |
Destructor. | |
size_t | getImin () const |
Get imin_. | |
size_t | getImax () const |
Get imax_. | |
size_t | getI0 () const |
Get i0_. | |
virtual double | getMass () const =0 |
Get mass of particule. | |
void | metric (SmartPointer< Metric::Generic >) |
Set metric Smartpointer. | |
SmartPointer< Metric::Generic > | metric () const |
Get metric. | |
void | initCoord (std::vector< double > const &) |
std::vector< double > | initCoord () const |
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. More... | |
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. | |
virtual std::string | className () const |
"Worldline" | |
virtual std::string | className_l () const |
"worldline" | |
void | integrator (std::string const &type) |
Set the integrator. More... | |
std::string | integrator () const |
Describe the integrator used by state_. | |
double | deltaMin () const |
Get delta_min_. | |
void | deltaMin (double h1) |
Set delta_min_. | |
double | deltaMax () const |
Get delta_max_. | |
void | absTol (double) |
Set abstol_. | |
double | absTol () const |
Get abstol_. | |
void | relTol (double) |
Set reltol_. | |
double | relTol () const |
Get reltol_. | |
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_. | |
void | delta (const double delta) |
Assignment to another Worldline. More... | |
void | delta (double, const std::string &unit) |
Set delta_ in specified units. | |
double | delta () const |
Get delta_. | |
double | delta (const std::string &unit) const |
Get delta_ in specified units. | |
double | tMin () const |
Get tmin_. | |
double | tMin (const std::string &unit) const |
Get tmin_ in specified unit. | |
void | tMin (double tlim) |
Set tmin_. | |
void | tMin (double, const std::string &unit) |
Set tmin_ in specified unit. | |
void | adaptive (bool mode) |
Set adaptive_. | |
bool | adaptive () const |
Get adaptive_. | |
void | secondary (bool sec) |
Set secondary_. | |
bool | secondary () const |
Get secondary_. | |
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) More... | |
void | setCst (double const *cst, size_t const ncsts) |
Set Metric-specific constants of motion. More... | |
void | setInitialCondition (SmartPointer< Metric::Generic > gg, const double coord[8], const int dir) |
Set or re-set the initial condition prior to integration. More... | |
void | getInitialCoord (double dest[8]) const |
Get initial coordinate. | |
void | getCoord (size_t index, double dest[8]) const |
Get coordinates corresponding to index. | |
void | getCartesianPos (size_t index, double dest[4]) const |
Get Cartesian expression of 4-position at index. | |
virtual void | xStore (size_t ind, double coord[8]) |
Store coord at index ind. | |
virtual void | xFill (double tlim) |
Fill x0, x1... by integrating the Worldline from previously set inittial condition to time tlim. | |
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. More... | |
void | get_xyz (double *x, double *y, double *z) const |
Get 3-position in cartesian coordinates for computed dates. | |
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. More... | |
void | getCoord (double *x0, double *x1, double *x2, double *x3) const |
Get all computed positions. More... | |
void | checkPhiTheta (double coord[8]) const |
Bring θ in [0,Π] and φ in [0,2Π]. More... | |
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. | |
Public Attributes | |
int | stopcond |
Whether and why integration is finished. | |
Protected Member Functions | |
virtual void | xAllocate () |
Allocate x0, x1 etc. with default size. More... | |
virtual void | xAllocate (size_t size) |
Allocate x0, x1 etc. with a specified size. More... | |
virtual size_t | xExpand (int dir) |
Expand x0, x1 etc... to hold more elements. More... | |
virtual void | xExpand (double *&x, int dir) |
Expand one array to hold more elements. More... | |
virtual void | tell (Gyoto::Hook::Teller *) |
This is how a Teller tells. More... | |
Protected Attributes | |
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_ |
θ or y | |
double * | x3_ |
φ or z | |
double * | x0dot_ |
tdot or Tdot | |
double * | x1dot_ |
rdot or xdot | |
double * | x2dot_ |
θdot or ydot | |
double * | x3dot_ |
φdot 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. | |
bool | secondary_ |
Experimental: choose 0 to compute only primary image. More... | |
double | delta_ |
Initial integrating step. More... | |
double | tmin_ |
Time limit for the integration (geometrical units) More... | |
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. | |
double | delta_min_ |
Minimum integration step for the adaptive integrator. More... | |
double | delta_max_ |
Maximum integration step for the adaptive integrator. More... | |
double | delta_max_over_r_ |
Numerical tuning parameter. More... | |
double | abstol_ |
Absolute tolerance of the integrator. More... | |
double | reltol_ |
Absolute tolerance of the integrator. More... | |
SmartPointer< Worldline::IntegState::Generic > | state_ |
An object to hold the integration state. | |
Timelike or null geodesics.
Their are two derived classes: Photon and Star. A Worldline can be integrated from an initial condition either backward or forward in time using xFill() (Photon::hit() also integrates the Worldline). Member state_ holds the integration state as well as an integrator. There are several kinds of integration states, that derive from IntegState::Generic.
The coordinates of the Worldline are stored in x0_, x1_, x2_, x3_, x0dot_, x1dot_, x2dot_ ans x3dot_. Those arrays are extended as needed using xExpand(). These coordinates can be retrieved using get_t(), get_xyz(), getCartesian(), getCoord() etc.
Worldline does not derive from Object, and does not instanciate a Property list. This is because this would lead to multiple inheritance of the Object base in derived classes. Instead, #GyotoWorldline.h provides a few macros that can be used to include the Worldline properties in a derived classe's Property list:
Refine constructor.
Meant to instanciate a copy of orig with a smaller step to refine integration, for instance for more accurate radiative transfer integration.
See Photon::Photon(Photon* orig, size_t i0, int dir, double step_max) and Photon::Refined.
orig | Worldline to refine |
i0 | Index of coordinate in orig to take as initial condition |
dir | Direction of integration |
step_max | Maximum integration step |
void Gyoto::Worldline::checkPhiTheta | ( | double | coord[8] | ) | const |
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".
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virtual |
Get delta max at a given position
[in] | pos | 4-position |
[in] | delta_max_external | external constraint on delta_max |
void Gyoto::Worldline::deltaMax | ( | double | h1 | ) |
Set delta_max_
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 , |
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double *const | yprime = NULL , |
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double *const | zprime = NULL |
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) |
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.
[in] | dates | List of dates for which the coordinates are to be computed; |
[in] | n_dates | Number of dates to compute ; |
[out] | x,y,z,xprime,yprime,zprime | Arrays 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. |
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 , |
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double *const | x1dot = NULL , |
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double *const | x2dot = NULL , |
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double *const | x3dot = NULL |
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) |
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.
dates | the list of dates for which the coordinates are to be computed; |
n_dates | the number of dates to compute ; |
x1dest,x2dest,x3dest,x0dot,x1dot,x2dot,x3dot | 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. |
void Gyoto::Worldline::getCoord | ( | double * | x0, |
double * | x1, | ||
double * | x2, | ||
double * | x3 | ||
) | const |
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 |
Returns the worldline's cst of motion (if any)
Return pointer to array holding the previously set Metric-specific constants of motion
void Gyoto::Worldline::integrator | ( | std::string const & | type | ) |
Set the integrator.
Initialize state_ to use the required integrator.
[in] | type | Either "Legacy" or (if GYOTO_HAVE_BOOST_INTEGRATORS) one of "runge_kutta_cash_karp54", "runge_kutta_fehlberg78", "runge_kutta_dopri5", "runge_kutta_cash_karp54_classic" |
void Gyoto::Worldline::setCst | ( | double const * | cst, |
size_t const | ncsts | ||
) |
Set Metric-specific constants of motion.
The will (re)allocate Worldline::cst_, copy cst into it, and set Worldline::cst_n_.
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virtual |
Set initial coordinate.
pos | initial 4-position |
vel | initial 3-velocity |
dir | direction of integration |
void Gyoto::Worldline::setInitialCondition | ( | SmartPointer< Metric::Generic > | gg, |
const double | coord[8], | ||
const int | dir | ||
) |
Set or re-set the initial condition prior to integration.
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; |
dir | direction: 1 for future, -1 for past. |
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protectedvirtual |
This is how a Teller tells.
A teller will basically call listener->tell(this).
msg | Teller* the Teller who is telling... Useful if the Listener listens to several Tellers. |
Reimplemented from Gyoto::Hook::Listener.
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protectedvirtual |
Allocate x0, x1 etc. with default size.
The default size is GYOTO_DEFAULT_X_SIZE
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protectedvirtual |
Allocate x0, x1 etc. with a specified size.
size | : number of cells in each array x0, x1 etc. |
Reimplemented in Gyoto::Astrobj::StarTrace.
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protectedvirtual |
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 |
Reimplemented in Gyoto::Astrobj::StarTrace.
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protectedvirtual |
Expand one array to hold more elements.
If you need to expand more arrays than x0_ ... x3_ and the dots, call this on your array before calling xExpand(int dir).
[in,out] | x | array to expand |
[in] | dir |
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protected |
Absolute tolerance of the integrator.
Used by the adaptive integrators implemented in IntegState::Boost. Refer to the boost::numeric::odeint documentation for more details.
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protected |
Initial integrating step.
Default: GYOTO_DEFAULT_DELTA
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protected |
Maximum integration step for the adaptive integrator.
The default (GYOTO_DEFAULT_DELTA_MAX) is usually fine.
For IntegState::Legacy, set it in the Metric instead!
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protected |
Numerical tuning parameter.
For IntegState::Legacy, set it in the Metric instead!
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.
The default (GYOTO_DEFAULT_DELTA_MAX_OVER_R) is usually fine.
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protected |
Minimum integration step for the adaptive integrator.
The default (GYOTO_DEFAULT_DELTA_MIN) is usually fine.
For IntegState::Legacy, set it in the Metric instead!
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protected |
Absolute tolerance of the integrator.
Used by the adaptive integrators implemented in IntegState::Boost. Refer to the boost::numeric::odeint documentation for more details.
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protected |
Experimental: choose 0 to compute only primary image.
This feature is in development.
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protected |
Time limit for the integration (geometrical units)
Computation does not go back before tmin_. Default is -DBL_MAX. tmin_ is always expressed in geometrical units, it is essentially a tuning parameter for the ray-tracing process. tmin_ should be chosen to always be longer than the distance between the screen and the object.