Observation simulator tool. More...

#include <ctobssim.hpp>

Inheritance diagram for ctobssim:

Public Member Functions
	ctobssim (void)
	Void constructor. More...

	ctobssim (const GObservations &obs)
	Observations constructor. More...

	ctobssim (int argc, char *argv[])
	Command line constructor. More...

	ctobssim (const ctobssim &app)
	Copy constructor. More...

virtual	~ctobssim (void)
	Destructor. More...

ctobssim &	operator= (const ctobssim &app)
	Assignment operator. More...

void	clear (void)
	Clear ctobssim tool. More...

void	process (void)
	Process the ctobssim tool. More...

void	save (void)
	Save the selected event list(s) More...

void	publish (const std::string &name="")
	Publish event lists. More...

const double &	max_rate (void) const
	Return maximum photon rate. More...

void	max_rate (const double &max_rate)
	Set maximum photon rate. More...

void	models (const GModels &models)
	Set models for simulation. More...

Public Member Functions inherited from ctobservation
	ctobservation (const std::string &name, const std::string &version)
	Name constructor. More...

	ctobservation (const std::string &name, const std::string &version, const GApplicationPars &pars)
	Application parameters constructor. More...

	ctobservation (const std::string &name, const std::string &version, int argc, char *argv[])
	Command line constructor. More...

	ctobservation (const std::string &name, const std::string &version, const GObservations &obs)
	Observations constructor. More...

	ctobservation (const ctobservation &app)
	Copy constructor. More...

virtual	~ctobservation (void)
	Destructor. More...

ctobservation &	operator= (const ctobservation &app)
	Assignment operator. More...

void	obs (const GObservations &obs)
	Set observation container. More...

const GObservations &	obs (void) const
	Return observation container. More...

Public Member Functions inherited from ctool
	ctool (const std::string &name, const std::string &version)
	Name constructor. More...

	ctool (const std::string &name, const std::string &version, const GApplicationPars &pars)
	Application parameter constructor. More...

	ctool (const std::string &name, const std::string &version, int argc, char *argv[])
	Command line constructor. More...

	ctool (const ctool &app)
	Copy constructor. More...

virtual	~ctool (void)
	Destructor. More...

ctool &	operator= (const ctool &app)
	Assignment operator. More...

virtual void	run (void)
	Run ctool. More...

virtual void	execute (void)
	Execute ctool. More...

Protected Member Functions
void	init_members (void)
	Initialise class members. More...

void	copy_members (const ctobssim &app)
	Copy class members. More...

void	free_members (void)
	Delete class members. More...

void	get_parameters (void)
	Get application parameters. More...

void	simulate_source (GCTAObservation obs, const GModels &models, GRan &ran, GLog wrklog=NULL)
	Simulate source events from photon list. More...

void	simulate_interval (GCTAObservation obs, const GCTAResponseIrf rsp, GCTAEventList events, const GModels &models, const GTime &tmin, const GTime &tmax, const GEnergy &etrue_min, const GEnergy &etrue_max, const GEnergy &ereco_min, const GEnergy &ereco_max, const GSkyDir &dir, const double &rad, const double &area, GRan &ran, GLog wrklog, int &indent, std::vector< int > &nphotons, std::vector< int > &nevents)
	Simulate source events for a time and energy interval. More...

void	simulate_time_slice (GCTAObservation obs, const GCTAResponseIrf rsp, GCTAEventList events, const GModelSky model, const int &mc_id, const GTime &tstart, const GTime &tstop, const GEnergy &etrue_min, const GEnergy &etrue_max, const GEnergy &ereco_min, const GEnergy &ereco_max, const GSkyDir &dir, const double &rad, const double &area, GRan &ran, GLog *wrklog, int &indent, int &nphotons, int &nevents)
	Simulate source events for a time slice. More...

GEbounds	get_ebounds (const GEbounds &ebounds) const
	Get energy boundaries. More...

double	get_area (GCTAObservation *obs, const GEnergy &emin, const GEnergy &emax) const
	Get simulation area (cm^2) More...

double	get_model_flux (const GModelSky model, const GEnergy &emin, const GEnergy &emax, const GSkyDir &centre, const double &radius, const int &indent, GLog wrklog)
	Determine sky model flux. More...

void	simulate_background (GCTAObservation obs, const GModels &models, GRan &ran, GLog wrklog=NULL)
	Simulate background events from model. More...

void	set_mc_id_names (GCTAObservation obs, const GModels &models, GLog wrklog=NULL)
	Set correspondance between Monte Carlo identifier and model names. More...

void	save_fits (void)
	Save event list in FITS format. More...

void	save_xml (void)
	Save event list(s) in XML format. More...

std::string	outfile (const int &index)
	Return output filename. More...

Protected Member Functions inherited from ctobservation
GCTAObservation *	first_unbinned_observation (void)
	Return first unbinned CTA observation. More...

GCTAObservation *	next_unbinned_observation (void)
	Return next unbinned CTA observation. More...

const GCTAObservation *	first_unbinned_observation (void) const
	Return first unbinned CTA observation (const version) More...

const GCTAObservation *	next_unbinned_observation (void) const
	Return next unbinned CTA observation (const version) More...

void	read_ogip_keywords (GFitsHDU *hdu) const
	Read OGIP keywords from FITS HDU. More...

void	write_ogip_keywords (GFitsHDU *hdu) const
	Write OGIP keywords in FITS HDU. More...

void	set_obs_statistic (const std::string &statistic)
	Set fit statistic for CTA observations. More...

void	set_obs_bounds ()
	Set observation boundaries for CTA observations. More...

void	save_events_fits (void)
	Save event list in FITS format. More...

void	save_events_xml (void)
	Save event list(s) in XML format. More...

void	init_members (void)
	Initialise class members. More...

void	copy_members (const ctobservation &app)
	Copy class members. More...

void	free_members (void)
	Delete class members. More...

Protected Member Functions inherited from ctool
void	init_members (void)
	Initialise class members. More...

void	copy_members (const ctool &app)
	Copy class members. More...

void	free_members (void)
	Delete class members. More...

void	sync_pfiles (void)
	Synchronise parameter files. More...

const bool &	read_ahead (void) const
	Signal whether parameters should be read ahead. More...

void	setup_observations (GObservations &obs, const bool &response=true, const bool &list=true, const bool &cube=true)
	Setup observation container. More...

void	setup_models (GObservations &obs, const std::string &name="")
	Setup model container. More...

GEbounds	create_ebounds (void)
	Create energy boundaries from user parameters. More...

GEnergies	create_energies (void)
	Create energies from user parameters. More...

GSkyMap	create_map (const GObservations &obs)
	Create a skymap from user parameters. More...

GCTAEventCube	create_cube (const GObservations &obs)
	Create a CTA event cube from user parameters. More...

GCTAObservation	create_cta_obs (void)
	Create a CTA observation from User parameters. More...

void	require_inobs (const std::string &method)
	Throws exception if inobs parameter is not valid. More...

void	require_inobs_nolist (const std::string &method)

void	require_inobs_nocube (const std::string &method)
	Throws exception if inobs parameter is a counts cube. More...

GCTARoi	get_roi (const GCTAPointing &pnt=GCTAPointing())
	Return RoI from User parameters. More...

GEbounds	get_ebounds (void)
	Return energy boundaries from User parameters. More...

GGti	get_gti (const GTimeReference &ref)
	Return Good Time Intervals from User parameter. More...

GCTAPointing	get_pointing (void)
	Return CTA pointing from User parameters. More...

GSkyDir	get_skydir (void)
	Return sky direction from User parameters. More...

std::string	set_outfile_name (const std::string &filename)
	Set output file name. More...

bool	is_stacked (void)
	Query user parameters for stacked analysis. More...

bool	is_onoff (void)
	Query user parameters for On/Off analysis. More...

void	log_parameters (const GChatter &chatter)
	Log application parameters. More...

void	log_observations (const GChatter &chatter, const GObservations &obs, const std::string &what="Observation")
	Log observation container. More...

void	log_models (const GChatter &chatter, const GModels &models, const std::string &what="Model")
	Log model container. More...

void	set_response (GObservations &obs)
	Set response for all CTA observations in container. More...

std::vector< bool >	set_edisp (GObservations &obs, const bool &edisp) const
	Set energy dispersion to CTA observations. More...

void	restore_edisp (GObservations &obs, const std::vector< bool > &edisp) const
	Restore energy dispersion flags of CTA observations. More...

void	set_obs_response (GCTAObservation *obs)
	Set response for CTA observation. More...

GObservations	get_observations (const bool &get_response=true)
	Get observation container. More...

GSkyDir	get_mean_pointing (const GObservations &obs)
	Derives mean pointing from CTA observations. More...

size_t	get_current_rss (void)
	Get current resident set size (physical memory use) in Bytes. More...

std::string	get_obs_header (const GObservation *obs) const
	Return observation header string. More...

GEnergies	insert_energy_boundaries (const GEnergies &energies, const GCTAObservation &obs)
	Insert observation energy boundaries into list of energies. More...

std::vector< bool >	cube_layer_usage (const GEbounds &cube_ebounds, const GEbounds &list_ebounds) const
	Determine the counts cube layer usage. More...

std::string	get_gtiname (const std::string &filename, const std::string &evtname) const
	Get Good Time Intervals extension name. More...

void	save_event_list (const GCTAObservation *obs, const std::string &infile, const std::string &evtname, const std::string &gtiname, const std::string &outfile) const
	Save event list into FITS file. More...

std::string	warn_too_few_energies (const GEnergies &energies) const
	Set warning string if there are too few energies. More...

std::string	warn_xml_suffix (const GFilename &filename) const
	Set warning string if file has no .xml suffix. More...

void	provide_help (void) const
	Dump help text in the console. More...

Protected Attributes
std::string	m_outevents
	Output events file. More...

std::string	m_prefix
	Prefix for multiple event lists. More...

int	m_startindex
	Start index for multiple event lists. More...

int	m_seed
	Random number generator seed. More...

int	m_eslices
	Number of energy slices. More...

bool	m_apply_edisp
	Apply energy dispersion? More...

double	m_max_rate
	Maximum photon rate. More...

GModels	m_models
	Optionally provided models. More...

bool	m_save_and_dispose
	Save and dispose immediately. More...

int	m_max_photons
	Maximum number of photons/slice. More...

std::vector< GRan >	m_rans
	Random number generators. More...

int	m_event_id
	Event identifier. More...

Protected Attributes inherited from ctobservation
GObservations	m_obs
	Observation container. More...

Protected Attributes inherited from ctool
bool	m_read_ahead
	Read ahead output parameters. More...

bool	m_use_xml
	Use XML file instead of FITS file for observations. More...

Detailed Description

Observation simulator tool.

This class simulates CTA observation(s) using Monte Carlo sampling of the source and background models. The class supports simulation of data of multiple CTA observations in one shot. If multiple CTA observations are processed and the save method is called, events FITS files will be written for each observation.

Definition at line 50 of file ctobssim.hpp.

Constructor & Destructor Documentation

ctobssim::ctobssim ( void )

Void constructor.

Constructs an empty ctobssim tool.

Definition at line 74 of file ctobssim.cpp.

References init_members().

ctobssim::ctobssim ( const GObservations & obs )

explicit

Observations constructor.

Parameters

[in] obs Observation container.

Constructs ctobssim tool from an observation container.

Definition at line 91 of file ctobssim.cpp.

References init_members().

ctobssim::ctobssim	(	int	argc,
		char *	argv[]
	)

Command line constructor.

Parameters

[in]	argc	Number of arguments in command line.
[in]	argv	Array of command line arguments.

Constructs ctobssim tool using command line arguments for user parameter setting.

Definition at line 111 of file ctobssim.cpp.

References init_members().

ctobssim::ctobssim ( const ctobssim & app )

Copy constructor.

Parameters

[in] app Application.

Constructs ctobssim tool from another ctobssim instance.

Definition at line 129 of file ctobssim.cpp.

References copy_members(), and init_members().

ctobssim::~ctobssim ( void )

virtual

Destructor.

Destructs ctobssim tool.

Definition at line 147 of file ctobssim.cpp.

References free_members().

Member Function Documentation

void ctobssim::clear ( void )

virtual

Clear ctobssim tool.

Clears ctobssim tool.

Implements ctobservation.

Definition at line 206 of file ctobssim.cpp.

References free_members(), ctool::free_members(), ctobservation::free_members(), init_members(), ctool::init_members(), and ctobservation::init_members().

void ctobssim::copy_members ( const ctobssim & app )

protected

Copy class members.

Parameters

[in] app Application.

Definition at line 569 of file ctobssim.cpp.

References m_apply_edisp, m_eslices, m_event_id, m_max_photons, m_max_rate, m_models, m_outevents, m_prefix, m_rans, m_save_and_dispose, m_seed, and m_startindex.

Referenced by ctobssim(), and operator=().

void ctobssim::free_members ( void )

protected

Delete class members.

Definition at line 595 of file ctobssim.cpp.

Referenced by clear(), operator=(), and ~ctobssim().

double ctobssim::get_area	(	GCTAObservation *	obs,
		const GEnergy &	emin,
		const GEnergy &	emax
	)		const

protected

Get simulation area (cm^2)

Parameters

[in]	obs	Pointer on CTA observation.
[in]	emin	Minimum true energy.
[in]	emax	Maximum true energy.

Returns: Simulation area (cm^2).

Get the simulation area for an energy interval in units of cm^2. This is done by extracting the maximum effective area value within the energy range [emin,emax] and by multiplying this value by 2 for security. The effective area is sampled at 100 energy values within the energy interval.

Definition at line 1303 of file ctobssim.cpp.

References G_GET_AREA.

Referenced by simulate_source().

GEbounds ctobssim::get_ebounds ( const GEbounds & ebounds ) const

protected

Get energy boundaries.

Parameters

[in] ebounds Energy boundaries of events.

Returns: Energy boundaries for simulation.

Get the energy boundaries for the source simulation.

Todo:: Need to take care of the (rare) case that there are distinct energy boundaries in the event list. In that case we need to create mixed energy boundaries.

Definition at line 1280 of file ctobssim.cpp.

References m_eslices.

double ctobssim::get_model_flux	(	const GModelSky *	model,
		const GEnergy &	emin,
		const GEnergy &	emax,
		const GSkyDir &	centre,
		const double &	radius,
		const int &	indent,
		GLog *	wrklog
	)

protected

Determine sky model flux.

Parameters

[in]	model	Sky model.
[in]	emin	Minimum energy.
[in]	emax	Maximum energy.
[in]	centre	Centre of region for photon rate determination.
[in]	radius	Radius of region for photon rate determination (degrees).
[in]	indent	Indent for logging.
[in,out]	wrklog	Pointer to logger.

Returns: Model flux (photons/cm2/sec).

Definition at line 1350 of file ctobssim.cpp.

Referenced by simulate_interval().

void ctobssim::get_parameters ( void )

protected

Get application parameters.

Get all task parameters from parameter file or (if required) by querying the user. Most parameters are only required if no observation exists so far in the observation container. In this case, a single CTA observation will be added to the container, using the definition provided in the parameter file.

Definition at line 611 of file ctobssim.cpp.

References G_GET_PARAMETERS, ctool::get_observations(), ctool::log_parameters(), m_apply_edisp, m_eslices, m_max_rate, m_models, ctobservation::m_obs, m_rans, m_seed, m_startindex, cscripts.mputils::nthreads(), ctool::read_ahead(), ctool::require_inobs_nocube(), ctobservation::set_obs_bounds(), and ctool::setup_observations().

Referenced by process().

void ctobssim::init_members ( void )

protected

Initialise class members.

The thrown area is fixed to pi*(2500^2) m2, which is the same value that is used in the Monte Carlo simulations (information from Konrad Bernloehr)

< Maximum number of photons / time slice

Definition at line 537 of file ctobssim.cpp.

References m_apply_edisp, m_eslices, m_event_id, m_max_photons, m_max_rate, m_models, m_outevents, m_prefix, m_rans, m_save_and_dispose, m_seed, and m_startindex.

Referenced by clear(), ctobssim(), and operator=().

const double & ctobssim::max_rate ( void ) const

inline

Return maximum photon rate.

Returns: Reference to maximum photon rate.

Definition at line 165 of file ctobssim.hpp.

References m_max_rate.

Referenced by max_rate().

void ctobssim::max_rate ( const double & max_rate )

inline

Set maximum photon rate.

Parameters

[in] max_rate Maximum photon rate.

Definition at line 177 of file ctobssim.hpp.

References m_max_rate, and max_rate().

void ctobssim::models ( const GModels & models )

inline

Set models for simulation.

Parameters

[in] models Model container.

Sets the model container that should be used for simulations. If a model container exists already in the input observations the model container will be overwritten. The models will not be queried, and any model specified using the "inmodel" parameter will be ignored.

Definition at line 195 of file ctobssim.hpp.

References m_models.

Referenced by process().

ctobssim & ctobssim::operator= ( const ctobssim & app )

Assignment operator.

Parameters

[in] app ctobssim tool.

Returns: ctobssim tool.

Assigns ctobssim tool.

Definition at line 171 of file ctobssim.cpp.

References copy_members(), free_members(), init_members(), and ctobservation::operator=().

std::string ctobssim::outfile ( const int & index )

protected

Return output filename.

Parameters

[in] index Observation index

Returns: Output filename

Return output filename for observation with index.

Definition at line 1792 of file ctobssim.cpp.

References m_outevents, m_prefix, m_startindex, and ctool::m_use_xml.

Referenced by process(), and save_xml().

void ctobssim::process ( void )

virtual

Process the ctobssim tool.

Gets the user parameters, loops over all CTA observations in the observation container, and simulate events for each observation.

Implements ctobservation.

Definition at line 235 of file ctobssim.cpp.

References ctool::get_obs_header(), get_parameters(), ctool::log_observations(), m_apply_edisp, ctobservation::m_obs, m_rans, m_save_and_dispose, m_startindex, ctool::m_use_xml, models(), ctobservation::obs(), outfile(), publish(), ctool::read_ahead(), ctool::restore_edisp(), ctool::set_edisp(), set_mc_id_names(), simulate_background(), and simulate_source().

void ctobssim::publish ( const std::string & name = "" )

Publish event lists.

Parameters

[in] name Event list name.

Definition at line 476 of file ctobssim.cpp.

References CTOBSSIM_NAME, ctobservation::m_obs, ctool::m_use_xml, and ctobservation::obs().

Referenced by process().

void ctobssim::save ( void )

virtual

Save the selected event list(s)

This method saves the selected event list(s) into FITS file(s). There are two modes, depending on the m_use_xml flag.

If m_use_xml is true, all selected event list(s) will be saved into FITS files, where the output filenames are constructued from the input filenames by prepending the m_prefix string to name. Any path information will be stripped form the input name, hence event files will be written into the local working directory (unless some path information is present in the prefix). In addition, an XML file will be created that gathers the filename information for the selected event list(s). If an XML file was present on input, all metadata information will be copied from this input file.

If m_use_xml is false, the selected event list will be saved into a FITS file.

Implements ctobservation.

Definition at line 451 of file ctobssim.cpp.

References ctobservation::m_obs, ctool::m_use_xml, save_fits(), and save_xml().

void ctobssim::save_fits ( void )

protected

Save event list in FITS format.

Save the event list as a FITS file. The filename of the FITS file is specified by the outfile parameter.

Definition at line 1692 of file ctobssim.cpp.

References ctobservation::m_obs, m_outevents, m_save_and_dispose, and ctobservation::obs().

Referenced by save().

void ctobssim::save_xml ( void )

protected

Save event list(s) in XML format.

Save the event list(s) into FITS files and write the file path information into a XML file. The filename of the XML file is specified by the outfile parameter, the filename(s) of the event lists are built by prepending a prefix to the input event list filenames. Any path present in the input filename will be stripped, i.e. the event list(s) will be written in the local working directory (unless a path is specified in the prefix).

Definition at line 1730 of file ctobssim.cpp.

References ctobservation::m_obs, m_outevents, m_save_and_dispose, ctobservation::obs(), outfile(), and ctool::warn_xml_suffix().

Referenced by save().

void ctobssim::set_mc_id_names	(	GCTAObservation *	obs,
		const GModels &	models,
		GLog *	wrklog = `NULL`
	)

protected

Set correspondance between Monte Carlo identifier and model names.

Parameters

[in]	obs	Pointer on CTA observation.
[in]	models	Models.
[in]	wrklog	Pointer to logger.

Sets the correspondance between Monte Carlo identifier and model names. The method collects all Monte Carlo identifiers from the event list and sets the corresponding source names using the GCTAEventList::set_mc_id_names method.

Definition at line 1611 of file ctobssim.cpp.

Referenced by process().

void ctobssim::simulate_background	(	GCTAObservation *	obs,
		const GModels &	models,
		GRan &	ran,
		GLog *	wrklog = `NULL`
	)

protected

Simulate background events from model.

Parameters

[in]	obs	Pointer on CTA observation.
[in]	models	Models.
[in]	ran	Random number generator.
[in]	wrklog	Pointer to logger.

Simulate background events from models. The events are stored as event list in the observation.

This method does nothing if the observation pointer is NULL.

Definition at line 1486 of file ctobssim.cpp.

References m_event_id.

Referenced by process().

void ctobssim::simulate_interval	(	GCTAObservation *	obs,
		const GCTAResponseIrf *	rsp,
		GCTAEventList *	events,
		const GModels &	models,
		const GTime &	tmin,
		const GTime &	tmax,
		const GEnergy &	etrue_min,
		const GEnergy &	etrue_max,
		const GEnergy &	ereco_min,
		const GEnergy &	ereco_max,
		const GSkyDir &	dir,
		const double &	rad,
		const double &	area,
		GRan &	ran,
		GLog *	wrklog,
		int &	indent,
		std::vector< int > &	nphotons,
		std::vector< int > &	nevents
	)

protected

Simulate source events for a time and energy interval.

Parameters

[in]	obs	Pointer on CTA observation.
[in]	rsp	Pointer on CTA IRF response.
[in,out]	events	Pointer on CTA event list.
[in]	models	Model list.
[in]	tmin	Start time.
[in]	tmax	Stop time.
[in]	etrue_min	Minimum true energy.
[in]	etrue_max	Maximum true energy.
[in]	ereco_min	Minimum reconstructed energy.
[in]	ereco_max	Maximum reconstructed energy.
[in]	dir	Simulation cone centre.
[in]	rad	Simulation cone radius (degrees).
[in]	area	Simulation area (cm^2).
[in,out]	ran	Random number generator.
[in]	wrklog	Pointer to logger.
[in,out]	indent	Logger indent.
[in,out]	nphotons	Number of photons for all models.
[in,out]	nevents	Number of events for all models.

Simulate source events for a time and energy interval.

Definition at line 969 of file ctobssim.cpp.

References G_SIMULATE_INTERVAL, get_model_flux(), m_max_photons, m_max_rate, and simulate_time_slice().

Referenced by simulate_source().

void ctobssim::simulate_source	(	GCTAObservation *	obs,
		const GModels &	models,
		GRan &	ran,
		GLog *	wrklog = `NULL`
	)

protected

Simulate source events from photon list.

Parameters

[in]	obs	Pointer on CTA observation.
[in]	models	Model list.
[in,out]	ran	Random number generator.
[in]	wrklog	Pointer to logger.

Simulate source events from a photon list for a given CTA observation and all source models. The events are stored in form of an event list in the observation.

The method will loop over all Good Time Intervals (GTI) to perform the simulations. Within a given GTI the requested energy range is split into a number of energy slices so that the simulation area can be adapted to the effective area of the instrument (this avoids simulating a large number of sources photons at low energies while accepting only few of them do to the small effective area). In case that the flux of a source is large, the simulation may be done within time slices so that the memory requirements won't get too large.

This method does nothing if the observation pointer is NULL. It verifies if the observation has a CTA IRF response.

Definition at line 748 of file ctobssim.cpp.

References g_roi_margin, G_SIMULATE_SOURCE, get_area(), ctool::get_ebounds(), and simulate_interval().

Referenced by process().

void ctobssim::simulate_time_slice	(	GCTAObservation *	obs,
		const GCTAResponseIrf *	rsp,
		GCTAEventList *	events,
		const GModelSky *	model,
		const int &	mc_id,
		const GTime &	tstart,
		const GTime &	tstop,
		const GEnergy &	etrue_min,
		const GEnergy &	etrue_max,
		const GEnergy &	ereco_min,
		const GEnergy &	ereco_max,
		const GSkyDir &	dir,
		const double &	rad,
		const double &	area,
		GRan &	ran,
		GLog *	wrklog,
		int &	indent,
		int &	nphotons,
		int &	nevents
	)

protected

Simulate source events for a time slice.

Parameters

[in]	obs	Pointer on CTA observation.
[in]	rsp	Pointer on CTA response.
[in,out]	events	Pointer on CTA event list.
[in]	model	Model.
[in]	mc_id	Monte Carlo identifier of model.
[in]	tstart	Start time.
[in]	tstop	Stop time.
[in]	etrue_min	Minimum true energy.
[in]	etrue_max	Maximum true energy.
[in]	ereco_min	Minimum reconstructed energy.
[in]	ereco_max	Maximum reconstructed energy.
[in]	dir	Simulation cone centre.
[in]	rad	Simulation cone radius (degrees).
[in]	area	Simulation area (cm^2).
[in,out]	ran	Random number generator.
[in]	wrklog	Pointer to logger.
[in,out]	indent	Logger indent.
[in,out]	nphotons	Number of photons.
[in,out]	nevents	Number of events.