/***********************************************************************//**
* @brief Returns MC sky direction
*
* @param[in] ran Random number generator.
*
* @exception GException::feature_not_implemented
* Method not yet implemented
*
* This method returns a random sky direction according to the intensity
* distribution of the model sky map. It makes use of a cache array that
* contains the normalized cumulative flux values of the skymap. Using a
* uniform random number, this cache array is scanned using a bi-section
* method to determine the skymap pixel for which the position should be
* returned. To avoid binning problems, the exact position within the pixel
* is set by a uniform random number generator (neglecting thus pixel
* distortions). The fractional skymap pixel is then converted into a sky
* direction.
***************************************************************************/
GSkyDir GModelSpatialMap::mc(GRan& ran) const
{
// Allocate sky direction
GSkyDir dir;
// Determine number of skymap pixels
int npix = m_map.npix();
// Continue only if there are skymap pixels
if (npix > 0) {
// Get uniform random number
double u = ran.uniform();
// Get pixel index according to random number. We use a bi-section
// method to find the corresponding skymap pixel
int low = 0;
int high = npix;
while ((high - low) > 1) {
int mid = (low+high) / 2;
if (u < m_mc_cache[mid]) {
high = mid;
}
else if (m_mc_cache[mid] <= u) {
low = mid;
}
}
// Convert 1D pixel index to 2D pixel index
GSkyPixel pixel = m_map.pix2xy(low);
// Randomize pixel
pixel.x(pixel.x() + ran.uniform() - 0.5);
pixel.y(pixel.y() + ran.uniform() - 0.5);
// Get sky direction
dir = m_map.xy2dir(pixel);
} // endif: there were pixels in sky map
// Return sky direction
return dir;
}
/***************************************************************************
* @brief GSkymap_wcs_construct
***************************************************************************/
void TestGSky::test_GSkymap_wcs_construct(void)
{
// Set precision
double eps = 1.0e-5;
// Test void constructor
test_try("Test void constructor");
try {
GSkymap map;
test_try_success();
}
catch (std::exception &e) {
test_try_failure(e);
}
// Test non-Healpix constructors
test_try("Test non-Healpix constructors");
try {
GSkymap map1("CAR", "GAL", 0.0, 0.0, 1.0, 1.0, 100, 100);
test_try_success();
}
catch (std::exception &e) {
test_try_failure(e);
}
// Test CAR projection
test_try("Test CAR projection");
try {
GSkymap map1("CAR", "GAL", 138.817, 37.293, 0.521, 0.931, 100, 100);
GSkyDir dir;
for (int l = -180; l < 180; ++l) {
for (int b = -90; b < 90; ++b) {
dir.lb_deg(double(l),double(b));
GSkyPixel pixel = map1.dir2pix(dir);
GSkyDir dir_back = map1.pix2dir(pixel);
double dist = dir.dist_deg(dir_back);
if (dist > eps) {
throw exception_failure("Sky direction differs: dir="+dir.print()+" pixel="+pixel.print()+" dir_back"+ dir_back.print()+" dist="+gammalib::str(dist)+" deg");
}
}
}
test_try_success();
}
catch (std::exception &e) {
test_try_failure(e);
}
// Exit test
return;
}
/***********************************************************************//**
* @brief Test GSkyPixel class
*
* Test GSkyPixel class.
***************************************************************************/
void TestGSky::test_GSkyPixel(void)
{
// Test void constructor
test_try("Test void constructor");
try {
GSkyPixel pixel;
test_value(pixel.size(), 0);
test_try_success();
}
catch (std::exception &e) {
test_try_failure(e);
}
// Test 1D constructor
test_try("Test 1D constructor (int version)");
try {
GSkyPixel pixel(41);
test_assert(pixel.is_1D(), "Pixel is not 1D");
test_assert(!pixel.is_2D(), "Pixel is 2D but it should be 1D");
test_value(pixel.size(), 1);
test_value(pixel.index(), 41.0);
test_try_success();
}
catch (std::exception &e) {
test_try_failure(e);
}
// Test 1D constructor
test_try("Test 1D constructor (double version)");
try {
GSkyPixel pixel(41.001);
test_assert(pixel.is_1D(), "Pixel is not 1D");
test_assert(!pixel.is_2D(), "Pixel is 2D but it should be 1D");
test_value(pixel.size(), 1);
test_value(pixel.index(), 41.001);
test_try_success();
}
catch (std::exception &e) {
test_try_failure(e);
}
// Test 2D constructor
test_try("Test 2D constructor (int version)");
try {
GSkyPixel pixel(41,14);
test_assert(!pixel.is_1D(), "Pixel is 1D but it should be 2D");
test_assert(pixel.is_2D(), "Pixel is not 2D");
test_value(pixel.size(), 2);
test_value(pixel.x(), 41.0);
test_value(pixel.y(), 14.0);
test_try_success();
}
catch (std::exception &e) {
test_try_failure(e);
}
// Test 2D constructor
test_try("Test 2D constructor (double version)");
try {
GSkyPixel pixel(41.001,14.003);
test_assert(!pixel.is_1D(), "Pixel is 1D but it should be 2D");
test_assert(pixel.is_2D(), "Pixel is not 2D");
test_value(pixel.size(), 2);
test_value(pixel.x(), 41.001);
test_value(pixel.y(), 14.003);
test_try_success();
}
catch (std::exception &e) {
test_try_failure(e);
}
// Test 1D indexing
test_try("Test 1D indexing");
try {
GSkyPixel pixel;
test_value(pixel.size(), 0);
pixel = 41;
int index = pixel;
test_value(index, 41);
pixel = 41.001;
index = pixel;
test_value(index, 41);
double dindex = pixel;
test_value(dindex, 41.001);
test_try_success();
}
catch (std::exception &e) {
test_try_failure(e);
}
// Test cloning
test_try("Test cloning");
try {
GSkyPixel pixel;
test_value(pixel.size(), 0);
GSkyPixel* clone = pixel.clone();
test_value(clone->size(), 0);
delete clone;
pixel = 41;
clone = pixel.clone();
test_value(clone->size(), 1);
int index = pixel;
test_value(index, 41);
delete clone;
pixel.x(41.001);
pixel.y(14.003);
clone = pixel.clone();
test_value(clone->size(), 2);
test_value(clone->x(), 41.001);
test_value(clone->y(), 14.003);
delete clone;
test_try_success();
}
catch (std::exception &e) {
test_try_failure(e);
}
// Return
return;
}
/***********************************************************************//**
* @brief Fill events into counts cube
*
* @param[in] obs CTA observation.
*
* @exception GException::invalid_value
* No event list found in observation.
*
* Fills the events from an event list in the counts cube setup by init_cube.
***************************************************************************/
void ctbin::fill_cube(GCTAObservation* obs)
{
// Continue only if observation pointer is valid
if (obs != NULL) {
// Make sure that the observation holds a CTA event list. If this
// is not the case then throw an exception.
const GCTAEventList* events = dynamic_cast<const GCTAEventList*>(obs->events());
if (events == NULL) {
std::string msg = "CTA Observation does not contain an event "
"list. Event list information is needed to "
"fill the counts map.";
throw GException::invalid_value(G_FILL_CUBE, msg);
}
// Get the RoI
const GCTARoi& roi = events->roi();
// Initialise binning statistics
int num_outside_roi = 0;
int num_outside_map = 0;
int num_outside_ebds = 0;
int num_in_map = 0;
// Fill sky map
for (int i = 0; i < events->size(); ++i) {
// Get event
const GCTAEventAtom* event = (*events)[i];
// Determine sky pixel
GCTAInstDir* inst = (GCTAInstDir*)&(event->dir());
GSkyDir dir = inst->dir();
GSkyPixel pixel = m_cube.dir2pix(dir);
// Skip if pixel is outside RoI
if (roi.centre().dir().dist_deg(dir) > roi.radius()) {
num_outside_roi++;
continue;
}
// Skip if pixel is out of range
if (pixel.x() < -0.5 || pixel.x() > (m_cube.nx()-0.5) ||
pixel.y() < -0.5 || pixel.y() > (m_cube.ny()-0.5)) {
num_outside_map++;
continue;
}
// Determine energy bin. Skip if we are outside the energy range
int index = m_ebounds.index(event->energy());
if (index == -1) {
num_outside_ebds++;
continue;
}
// Fill event in skymap
m_cube(pixel, index) += 1.0;
num_in_map++;
} // endfor: looped over all events
// Append GTIs
m_gti.extend(events->gti());
// Update ontime and livetime
m_ontime += obs->ontime();
m_livetime += obs->livetime();
// Log filling results
if (logTerse()) {
log << gammalib::parformat("Events in list");
log << obs->events()->size() << std::endl;
log << gammalib::parformat("Events in cube");
log << num_in_map << std::endl;
log << gammalib::parformat("Event bins outside RoI");
log << num_outside_roi << std::endl;
log << gammalib::parformat("Events outside cube area");
log << num_outside_map << std::endl;
log << gammalib::parformat("Events outside energy bins");
log << num_outside_ebds << std::endl;
}
// Log cube
if (logExplicit()) {
log.header1("Counts cube");
log << m_cube << std::endl;
}
} // endif: observation was valid
// Return
return;
}
/***********************************************************************//**
* @brief Returns MC sky direction
*
* @param[in] energy Photon energy.
* @param[in] time Photon arrival time.
* @param[in,out] ran Random number generator.
* @return Sky direction.
*
* @exception GException::invalid_value
* No energy boundaries specified, or energy boundaries do not
* cover the specified @p energy.
*
* Returns a random sky direction according to the intensity distribution of
* the model sky map and the specified energy. The method makes use of a
* cache array that contains the normalised cumulative flux values for each
* of the sky maps in the cube. The specified energy is used to select the
* appropriate cache array from the cube. Using a uniform random number, the
* selected cache array is scanned using a bi-section method to determine
* the skymap pixel for which the position should be returned. To avoid
* binning problems, the exact position within the pixel is set by a uniform
* random number generator (neglecting thus pixel distortions). The
* fractional skymap pixel is then converted into a sky direction.
***************************************************************************/
GSkyDir GModelSpatialDiffuseCube::mc(const GEnergy& energy,
const GTime& time,
GRan& ran) const
{
// Allocate sky direction
GSkyDir dir;
// Fetch cube
fetch_cube();
// Determine number of skymap pixels
int npix = pixels();
// Continue only if there are skymap pixels
if (npix > 0) {
// If no energy boundaries are defined, throw an exception
if (m_ebounds.size() < 1) {
std::string msg = "The energy boundaries of the maps in the cube"
" have not been defined. Maybe the map cube file"
" is missing the \"ENERGIES\" extension which"
" defines the energy of each map in the cube.\n"
"Please provide the energy information.";
throw GException::invalid_value(G_MC, msg);
}
// Determine the map that corresponds best to the specified energy.
// This is not 100% clean, as ideally some map interpolation should
// be done to the exact energy specified. However, as long as the map
// does not change drastically with energy, taking the closest map
// seems to be fine.
int i = m_ebounds.index(energy);
if (i < 0) {
if (energy <= m_ebounds.emin()) {
i = 0;
}
else if (energy >= m_ebounds.emax()) {
i = m_ebounds.size()-1;
}
else {
std::string msg = "The specified energy "+energy.print()+" does"
" not fall in any of the energy boundaries of"
" the map cube.\n"
"Please make sure that the map cube energies"
" are properly defined.";
throw GException::invalid_value(G_MC, msg);
}
}
// Get uniform random number
double u = ran.uniform();
// Get pixel index according to random number. We use a bi-section
// method to find the corresponding skymap pixel
int offset = i * (npix+1);
int low = offset;
int high = offset + npix;
while ((high - low) > 1) {
int mid = (low+high) / 2;
if (u < m_mc_cache[mid]) {
high = mid;
}
else if (m_mc_cache[mid] <= u) {
low = mid;
}
}
// Convert sky map index to sky map pixel
GSkyPixel pixel = m_cube.inx2pix(low-offset);
// Randomize pixel
pixel.x(pixel.x() + ran.uniform() - 0.5);
pixel.y(pixel.y() + ran.uniform() - 0.5);
// Get sky direction
dir = m_cube.pix2dir(pixel);
} // endif: there were pixels in sky map
// Return sky direction
return dir;
}
/***********************************************************************//**
* @brief Bin events into a counts map
*
* @param[in] obs CTA observation.
*
* @exception GException::no_list
* No event list found in observation.
* @exception GCTAException::no_pointing
* No valid CTA pointing found.
*
* This method bins the events found in a CTA events list into a counts map
* and replaces the event list by the counts map in the observation. The
* energy boundaries of the counts map are also stored in the observation's
* energy boundary member.
*
* If the reference values for the map centre (m_xref, m_yref) are 9999.0,
* the pointing direction of the observation is taken as the map centre.
* Otherwise, the specified reference value is used.
***************************************************************************/
void ctbin::bin_events(GCTAObservation* obs)
{
// Continue only if observation pointer is valid
if (obs != NULL) {
// Make sure that the observation holds a CTA event list. If this
// is not the case then throw an exception.
if (dynamic_cast<const GCTAEventList*>(obs->events()) == NULL) {
throw GException::no_list(G_BIN_EVENTS);
}
// Setup energy range covered by data
GEnergy emin;
GEnergy emax;
GEbounds ebds;
emin.TeV(m_emin);
emax.TeV(m_emax);
ebds.setlog(emin, emax, m_enumbins);
// Get Good Time intervals
GGti gti = obs->events()->gti();
// Get map centre
double xref;
double yref;
if (m_xref != 9999.0 && m_yref != 9999.0) {
xref = m_xref;
yref = m_yref;
}
else {
// Get pointer on CTA pointing
const GCTAPointing *pnt = obs->pointing();
if (pnt == NULL) {
throw GCTAException::no_pointing(G_BIN_EVENTS);
}
// Set reference point to pointing
if (toupper(m_coordsys) == "GAL") {
xref = pnt->dir().l_deg();
yref = pnt->dir().b_deg();
}
else {
xref = pnt->dir().ra_deg();
yref = pnt->dir().dec_deg();
}
} // endelse: map centre set to pointing
// Create skymap
GSkymap map = GSkymap(m_proj, m_coordsys,
xref, yref, m_binsz, m_binsz,
m_nxpix, m_nypix, m_enumbins);
// Initialise binning statistics
int num_outside_map = 0;
int num_outside_ebds = 0;
int num_in_map = 0;
// Fill sky map
GCTAEventList* events = static_cast<GCTAEventList*>(const_cast<GEvents*>(obs->events()));
for (GCTAEventList::iterator event = events->begin(); event != events->end(); ++event) {
// Determine sky pixel
GCTAInstDir* inst = (GCTAInstDir*)&(event->dir());
GSkyDir dir = inst->dir();
GSkyPixel pixel = map.dir2xy(dir);
// Skip if pixel is out of range
if (pixel.x() < -0.5 || pixel.x() > (m_nxpix-0.5) ||
pixel.y() < -0.5 || pixel.y() > (m_nypix-0.5)) {
num_outside_map++;
continue;
}
// Determine energy bin. Skip if we are outside the energy range
int index = ebds.index(event->energy());
if (index == -1) {
num_outside_ebds++;
continue;
}
// Fill event in skymap
map(pixel, index) += 1.0;
num_in_map++;
} // endfor: looped over all events
// Log binning results
if (logTerse()) {
log << std::endl;
log.header1("Binning");
log << parformat("Events in list");
log << obs->events()->size() << std::endl;
log << parformat("Events in map");
log << num_in_map << std::endl;
log << parformat("Events outside map area");
log << num_outside_map << std::endl;
log << parformat("Events outside energy bins");
log << num_outside_ebds << std::endl;
}
// Log map
if (logTerse()) {
log << std::endl;
log.header1("Counts map");
log << map << std::endl;
}
// Create events cube from sky map
GCTAEventCube cube(map, ebds, gti);
// Replace event list by event cube in observation
obs->events(&cube);
} // endif: observation was valid
// Return
return;
}
