/***********************************************************************//**
* @brief Return deadtime correction
*
* @return Deadtime correction factor.
***************************************************************************/
inline
double GCTACubeExposure::deadc(void) const
{
return ((m_gti.ontime() > 0.0) ? m_livetime/m_gti.ontime() : 1.0);
}
/***********************************************************************//**
* @brief Setup observation container
*
* @exception GException::no_cube
* No event cube found in CTA observation.
*
* This method sets up the observation container for processing. There are
* two cases:
*
* If there are no observations in the actual observation container, the
* method will check in "infile" parameter. If this parameter is "NONE" or
* empty, the task parameters will be used to construct a model map.
* Otherwise, the method first tries to interpret the "infile" parameter as
* a counts map, and attemps loading of the file in an event cube. If this
* fails, the method tries to interpret the "infile" parameter as an
* observation definition XML file. If this also fails, an exception will
* be thrown.
*
* If observations exist already in the observation container, the method
* will simply keep them.
*
* Test if all CTA observations contain counts maps.
*
* Finally, if no models exist so far in the observation container, the
* models will be loaded from the model XML file.
***************************************************************************/
void ctmodel::setup_obs(void)
{
// If there are no observations in the container then try to build some
if (m_obs.size() == 0) {
// If no input filename has been specified, then create a model map
// from the task parameters
if ((m_infile == "NONE") || (gammalib::strip_whitespace(m_infile) == "")) {
// Set pointing direction
GCTAPointing pnt;
GSkyDir skydir;
skydir.radec_deg(m_ra, m_dec);
pnt.dir(skydir);
// Setup energy range covered by model
GEnergy emin(m_emin, "TeV");
GEnergy emax(m_emax, "TeV");
GEbounds ebds(m_enumbins, emin, emax);
// Setup time interval covered by model
GGti gti;
GTime tmin(m_tmin);
GTime tmax(m_tmax);
gti.append(tmin, tmax);
// Setup skymap
GSkymap map = GSkymap(m_proj, m_coordsys,
m_xref, m_yref, -m_binsz, m_binsz,
m_nxpix, m_nypix, m_enumbins);
// Create model cube from sky map
GCTAEventCube cube(map, ebds, gti);
// Allocate CTA observation
GCTAObservation obs;
// Set CTA observation attributes
obs.pointing(pnt);
obs.ontime(gti.ontime());
obs.livetime(gti.ontime()*m_deadc);
obs.deadc(m_deadc);
// Set event cube in observation
obs.events(cube);
// Append CTA observation to container
m_obs.append(obs);
// Signal that no XML file should be used for storage
m_use_xml = false;
} // endif: created model map from task parameters
// ... otherwise try to load information from the file
else {
// First try to open the file as a counts map
try {
// Allocate CTA observation
GCTAObservation obs;
// Load counts map in CTA observation
obs.load_binned(m_infile);
// Append CTA observation to container
m_obs.append(obs);
// Signal that no XML file should be used for storage
m_use_xml = false;
}
// ... otherwise try to open as XML file
catch (GException::fits_open_error &e) {
// Load observations from XML file. This will throw
// an exception if it fails.
m_obs.load(m_infile);
// Signal that XML file should be used for storage
m_use_xml = true;
}
} // endelse: loaded information from input file
} // endif: there was no observation in the container
// If there are no models associated with the observations then
// load now the model definition from the XML file
if (m_obs.models().size() == 0) {
m_obs.models(GModels(m_srcmdl));
}
// Check if all CTA observations contain an event cube and setup response
// for all observations
for (int i = 0; i < m_obs.size(); ++i) {
// Is this observation a CTA observation?
GCTAObservation* obs = dynamic_cast<GCTAObservation*>(m_obs[i]);
// Yes ...
if (obs != NULL) {
// Throw an exception if this observation does not contain
// an event cube
if (dynamic_cast<const GCTAEventCube*>(obs->events()) == NULL) {
throw GException::no_cube(G_SETUP_OBS);
}
// Set response if it isn't set already
if (obs->response().aeff() == NULL) {
// Set calibration database. If specified parameter is a
// directory then use this as the pathname to the calibration
// database. Otherwise interpret this as the instrument name,
// the mission being "cta"
GCaldb caldb;
if (gammalib::dir_exists(m_caldb)) {
caldb.rootdir(m_caldb);
}
else {
caldb.open("cta", m_caldb);
}
// Set reponse
obs->response(m_irf, caldb);
} // endif: observation already has a response
} // endif: observation was a CTA observation
} // endfor: looped over all observations
// Return
return;
}
/***********************************************************************//**
* @brief Return ontime
*
* @return Ontime (seconds).
***************************************************************************/
inline
const double& GCTACubeExposure::ontime(void) const
{
return (m_gti.ontime());
}
/***********************************************************************//**
* @brief Select events
*
* @param[in] obs CTA observation.
* @param[in] filename File name.
*
* Select events from a FITS file by making use of the selection possibility
* of the cfitsio library on loading a file. A selection string is created
* from the specified criteria that is appended to the filename so that
* cfitsio will automatically filter the event data. This selection string
* is then applied when opening the FITS file. The opened FITS file is then
* saved into a temporary file which is the loaded into the actual CTA
* observation, overwriting the old CTA observation. The ROI, GTI and EBounds
* of the CTA event list are then set accordingly to the specified selection.
* Finally, the temporary file created during this process is removed.
*
* Good Time Intervals of the observation will be limited to the time
* interval [m_tmin, m_tmax]. If m_tmin=m_tmax=0, no time selection is
* performed.
*
* @todo Use INDEF instead of 0.0 for pointing as RA/DEC selection
***************************************************************************/
void ctselect::select_events(GCTAObservation* obs, const std::string& filename)
{
// Allocate selection string
std::string selection;
char cmin[80];
char cmax[80];
char cra[80];
char cdec[80];
char crad[80];
// Set requested selections
bool select_time = (m_tmin != 0.0 || m_tmax != 0.0);
// Set RA/DEC selection
double ra = m_ra;
double dec = m_dec;
if (m_usepnt) {
const GCTAPointing *pnt = obs->pointing();
ra = pnt->dir().ra_deg();
dec = pnt->dir().dec_deg();
}
// Set time selection interval. We make sure here that the time selection
// interval cannot be wider than the GTIs covering the data. This is done
// using GGti's reduce() method.
if (select_time) {
// Reduce GTIs to specified time interval. The complicated cast is
// necessary here because the gti() method is declared const, so
// we're not officially allowed to modify the GTIs.
((GGti*)(&obs->events()->gti()))->reduce(m_timemin, m_timemax);
} // endif: time selection was required
// Save GTI for later usage
GGti gti = obs->events()->gti();
// Make time selection
if (select_time) {
// Extract effective time interval in CTA reference time. We need
// this reference for filtering.
double tmin = gti.tstart().convert(m_cta_ref);
double tmax = gti.tstop().convert(m_cta_ref);
// Format time with sufficient accuracy and add to selection string
sprintf(cmin, "%.8f", tmin);
sprintf(cmax, "%.8f", tmax);
selection = "TIME >= "+std::string(cmin)+" && TIME <= "+std::string(cmax);
if (logTerse()) {
log << parformat("Time range");
log << tmin << " - " << tmax << " s" << std::endl;
}
if (selection.length() > 0) {
selection += " && ";
}
}
// Make energy selection
sprintf(cmin, "%.8f", m_emin);
sprintf(cmax, "%.8f", m_emax);
selection += "ENERGY >= "+std::string(cmin)+" && ENERGY <= "+std::string(cmax);
if (logTerse()) {
log << parformat("Energy range");
log << m_emin << " - " << m_emax << " TeV" << std::endl;
}
if (selection.length() > 0) {
selection += " && ";
}
// Make ROI selection
sprintf(cra, "%.6f", ra);
sprintf(cdec, "%.6f", dec);
sprintf(crad, "%.6f", m_rad);
selection += "ANGSEP("+std::string(cra)+"," +
std::string(cdec)+",RA,DEC) <= " +
std::string(crad);
if (logTerse()) {
log << parformat("Acceptance cone centre");
log << "RA=" << ra << ", DEC=" << dec << " deg" << std::endl;
log << parformat("Acceptance cone radius");
log << m_rad << " deg" << std::endl;
}
if (logTerse()) {
log << parformat("cfitsio selection");
log << selection << std::endl;
}
// Add additional expression
if (strip_whitespace(m_expr).length() > 0) {
if (selection.length() > 0) {
selection += " && ";
}
selection += "("+strip_whitespace(m_expr)+")";
}
// Build input filename including selection expression
std::string expression = filename;
if (selection.length() > 0)
expression += "[EVENTS]["+selection+"]";
if (logTerse()) {
log << parformat("FITS filename");
log << expression << std::endl;
}
// Open FITS file
GFits file(expression);
// Log selected FITS file
if (logExplicit()) {
log << std::endl;
log.header1("FITS file content after selection");
log << file << std::endl;
}
// Check if we have an EVENTS HDU
if (!file.hashdu("EVENTS")) {
std::string message = "No \"EVENTS\" extension found in FITS file "+
expression+".";
throw GException::app_error(G_SELECT_EVENTS, message);
}
// Determine number of events in EVENTS HDU
int nevents = file.table("EVENTS")->nrows();
// If the selected event list is empty then append an empty event list
// to the observation. Otherwise load the data from the temporary file.
if (nevents < 1) {
// Create empty event list
GCTAEventList eventlist;
// Append list to observation
obs->events(&eventlist);
}
else {
// Get temporary file name
std::string tmpname = std::tmpnam(NULL);
// Save FITS file to temporary file
file.saveto(tmpname, true);
// Load observation from temporary file
obs->load_unbinned(tmpname);
// Remove temporary file
std::remove(tmpname.c_str());
}
// Get CTA event list pointer
GCTAEventList* list =
static_cast<GCTAEventList*>(const_cast<GEvents*>(obs->events()));
// Set ROI
GCTARoi roi;
GCTAInstDir instdir;
instdir.radec_deg(ra, dec);
roi.centre(instdir);
roi.radius(m_rad);
list->roi(roi);
// Set GTI
list->gti(gti);
// Set energy boundaries
GEbounds ebounds;
GEnergy emin;
GEnergy emax;
emin.TeV(m_emin);
emax.TeV(m_emax);
ebounds.append(emin, emax);
list->ebounds(ebounds);
// Recompute ontime and livetime.
GTime meantime = 0.5 * (gti.tstart() + gti.tstop());
obs->ontime(gti.ontime());
obs->livetime(gti.ontime() * obs->deadc(meantime));
// Return
return;
}
