/***********************************************************************//**
* @brief Test CTA Npred computation
*
* Tests the Npred computation for the diffuse source model. This is done
* by loading the model from the XML file and by calling the
* GCTAObservation::npred method which in turn calls the
* GCTAResponse::npred_diffuse method. The test takes a few seconds.
***************************************************************************/
void TestGCTAResponse::test_response_npred_diffuse(void)
{
// Set reference value
double ref = 11212.26274;
// Set parameters
double src_ra = 201.3651;
double src_dec = -43.0191;
double roi_rad = 4.0;
// Setup ROI centred on Cen A with a radius of 4 deg
GCTARoi roi;
GCTAInstDir instDir;
instDir.radec_deg(src_ra, src_dec);
roi.centre(instDir);
roi.radius(roi_rad);
// Setup pointing on Cen A
GSkyDir skyDir;
skyDir.radec_deg(src_ra, src_dec);
GCTAPointing pnt;
pnt.dir(skyDir);
// Setup dummy event list
GGti gti;
GEbounds ebounds;
GTime tstart(0.0);
GTime tstop(1800.0);
GEnergy emin;
GEnergy emax;
emin.TeV(0.1);
emax.TeV(100.0);
gti.append(tstart, tstop);
ebounds.append(emin, emax);
GCTAEventList events;
events.roi(roi);
events.gti(gti);
events.ebounds(ebounds);
// Setup dummy CTA observation
GCTAObservation obs;
obs.ontime(1800.0);
obs.livetime(1600.0);
obs.deadc(1600.0/1800.0);
obs.response(cta_irf, cta_caldb);
obs.events(&events);
obs.pointing(pnt);
// Load models for Npred computation
GModels models(cta_rsp_xml);
// Perform Npred computation
double npred = obs.npred(models, NULL);
// Test Npred
test_value(npred, ref, 1.0e-5, "Diffuse Npred computation");
// Return
return;
}
/***********************************************************************//**
* @brief Set exposure cube from one CTA observation
*
* @param[in] obs CTA observation.
*
* Set the exposure cube from a single CTA observations. The cube pixel
* values are computed as product of the effective area and the livetime.
*
* @todo: Throw an exception if response is not valid
***************************************************************************/
void GCTACubeExposure::set(const GCTAObservation& obs)
{
// Clear GTIs, reset livetime and exposure cube pixels
m_gti.clear();
m_livetime = 0.0;
m_cube = 0.0;
// Extract region of interest from CTA observation
GCTARoi roi = obs.roi();
// Get references on CTA response and pointing direction
const GCTAResponseIrf* rsp = dynamic_cast<const GCTAResponseIrf*>(obs.response());
const GSkyDir& pnt = obs.pointing().dir();
// Continue only if response is valid
if (rsp != NULL) {
// Loop over all pixels in sky map
for (int pixel = 0; pixel < m_cube.npix(); ++pixel) {
// Get pixel sky direction
GSkyDir dir = m_cube.inx2dir(pixel);
// Continue only if pixel is within RoI
if (roi.centre().dir().dist_deg(dir) <= roi.radius()) {
// Compute theta angle with respect to pointing direction
// in radians
double theta = pnt.dist(dir);
// Loop over all exposure cube energy bins
for (int iebin = 0; iebin < m_ebounds.size(); ++iebin){
// Get logE/TeV
double logE = m_ebounds.elogmean(iebin).log10TeV();
// Set exposure cube (effective area * lifetime)
m_cube(pixel, iebin) = rsp->aeff(theta, 0.0, 0.0, 0.0, logE) *
obs.livetime();
} // endfor: looped over energy bins
} // endif: pixel was within RoI
} // endfor: looped over all pixels
// Append GTIs and increment livetime
m_gti.extend(obs.gti());
m_livetime += obs.livetime();
} // endif: response was valid
// Return
return;
}
/***********************************************************************//**
* @brief Extract ROI from data sub-space keywords
*
* @param[in] hdu FITS HDU
*
* @exception GException::invalid_value
* Invalid ROI data sub-space encountered
*
* Reads the ROI data sub-space keywords by searching for a DSTYPx keyword
* named "POS(RA,DEC)". The data sub-space information is expected to be in
* the format "CIRCLE(267.0208,-24.78,4.5)", where the 3 arguments are Right
* Ascension, Declination and radius in units of degrees. No detailed syntax
* checking is performed.
*
* If no ROI information has been found, an GCTARoi object with initial
* values will be returned.
***************************************************************************/
GCTARoi gammalib::read_ds_roi(const GFitsHDU& hdu)
{
// Initialise ROI
GCTARoi roi;
// Get number of data sub-space keywords (default to 0 if keyword is
// not found)
int ndskeys = (hdu.has_card("NDSKEYS")) ? hdu.integer("NDSKEYS") : 0;
// Loop over all data selection keys
for (int i = 1; i <= ndskeys; ++i) {
// Set data sub-space key strings
std::string type_key = "DSTYP"+gammalib::str(i);
//std::string unit_key = "DSUNI"+gammalib::str(i);
std::string value_key = "DSVAL"+gammalib::str(i);
// Continue only if type_key is found and if this key is POS(RA,DEC)
if (hdu.has_card(type_key) && hdu.string(type_key) == "POS(RA,DEC)") {
// ...
//std::string unit = gammalib::toupper(hdu.string(unit_key));
std::string value = hdu.string(value_key);
std::string value_proc = gammalib::strip_chars(value, "CIRCLE(");
value_proc = gammalib::strip_chars(value_proc, ")");
std::vector<std::string> args = gammalib::split(value_proc, ",");
if (args.size() == 3) {
double ra = gammalib::todouble(args[0]);
double dec = gammalib::todouble(args[1]);
double rad = gammalib::todouble(args[2]);
GCTAInstDir dir;
dir.dir().radec_deg(ra, dec);
roi.centre(dir);
roi.radius(rad);
}
else {
std::string msg = "Invalid acceptance cone value \""+value+
"\" encountered in data sub-space "
"key \""+value_key+"\".";
throw GException::invalid_value(G_READ_DS_ROI, msg);
}
} // endif: POS(RA,DEC) type found
} // endfor: looped over data sub-space keys
// Return roi
return roi;
}
/***********************************************************************//**
* @brief Test CTA npsf computation
***************************************************************************/
void TestGCTAResponse::test_response_npsf(void)
{
// Setup CTA response
GCTAResponse rsp;
rsp.caldb(cta_caldb);
rsp.load(cta_irf);
// Setup npsf computation
GSkyDir srcDir;
GEnergy srcEng;
GTime srcTime;
GCTAPointing pnt;
GCTARoi roi;
GCTAInstDir instDir;
instDir.radec_deg(0.0, 0.0);
roi.centre(instDir);
roi.radius(2.0);
srcEng.TeV(0.1);
// Test PSF centred on ROI
srcDir.radec_deg(0.0, 0.0);
double npsf = rsp.npsf(srcDir, srcEng.log10TeV(), srcTime, pnt, roi);
test_value(npsf, 1.0, 1.0e-3, "PSF(0,0) integration");
// Test PSF offset but inside ROI
srcDir.radec_deg(1.0, 1.0);
npsf = rsp.npsf(srcDir, srcEng.log10TeV(), srcTime, pnt, roi);
test_value(npsf, 1.0, 1.0e-3, "PSF(1,1) integration");
// Test PSF outside and overlapping ROI
srcDir.radec_deg(0.0, 2.0);
npsf = rsp.npsf(srcDir, srcEng.log10TeV(), srcTime, pnt, roi);
test_value(npsf, 0.492373, 1.0e-3, "PSF(0,2) integration");
// Test PSF outside ROI
srcDir.radec_deg(2.0, 2.0);
npsf = rsp.npsf(srcDir, srcEng.log10TeV(), srcTime, pnt, roi);
test_value(npsf, 0.0, 1.0e-3, "PSF(2,2) integration");
// Return
return;
}
/***********************************************************************//**
* @brief Fill model into model cube
*
* @param[in] obs CTA observation.
*
* Adds the expected number of events for a given observation to the events
* that are already found in the model cube. The method also updates the
* GTI of the model cube so that cube GTI is a list of the GTIs of all
* observations that were used to generate the model cube.
***************************************************************************/
void ctmodel::fill_cube(const GCTAObservation* obs)
{
// Continue only if observation pointer is valid
if (obs != NULL) {
// Get GTI and energy boundaries references for observation
const GGti& gti = obs->events()->gti();
const GEbounds& obs_ebounds = obs->ebounds();
// Get cube energy boundaries
const GEbounds& cube_ebounds = m_cube.ebounds();
// Initialise empty, invalid RoI
GCTARoi roi;
// Retrieve RoI in case we have an unbinned observation
if (obs->eventtype() == "EventList") {
roi = obs->roi();
}
// Initialise statistics
double sum = 0.0;
int num_outside_ebds = 0;
int num_outside_roi = 0;
// Setup cube GTIs for this observation
m_cube.gti(obs->events()->gti());
// Loop over all cube bins
for (int i = 0; i < m_cube.size(); ++i) {
// Get cube bin
GCTAEventBin* bin = m_cube[i];
// Skip bin if it is outside the energy range of the observation
int index = cube_ebounds.index(bin->energy());
if (index == -1 ||
!obs_ebounds.contains(cube_ebounds.emin(index)+g_energy_margin,
cube_ebounds.emax(index)-g_energy_margin)) {
num_outside_ebds++;
continue;
}
// Check if RoI is valid, i.e. check if we have an unbinned
// observation
if (roi.is_valid()) {
// Skip bin if it is outside the RoI of the observation
if (!roi.contains(*bin)) {
num_outside_roi++;
continue;
}
} // endif: RoI was not valid
// Get actual bin value
double value = bin->counts();
// Compute model value for cube bin
double model = m_obs.models().eval(*bin, *obs) * bin->size();
// Add model to actual value
value += model;
sum += model;
// Store value
bin->counts(value);
} // endfor: looped over all cube bins
// Append GTIs of observation to list of GTIs
m_gti.extend(gti);
// Update GTIs
m_cube.gti(m_gti);
// Log results
if (logTerse()) {
log << gammalib::parformat("Model events in cube");
log << sum << std::endl;
log << gammalib::parformat("Bins outside energy range");
log << num_outside_ebds << std::endl;
log << gammalib::parformat("Bins outside RoI");
log << num_outside_roi << std::endl;
}
// Log cube
if (logExplicit()) {
log.header2("Model cube");
log << m_cube << std::endl;
}
} // endif: observation was valid
// Return
return;
}
/***********************************************************************//**
* @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;
}
