/***********************************************************************//**
* @brief Evaluate function
*
* @param[in] event Observed event.
* @param[in] obs Observation.
* @return Function value.
*
* @exception GException::invalid_argument
* Specified observation is not of the expected type.
*
* @todo Make sure that DETX and DETY are always set in GCTAInstDir.
***************************************************************************/
double GCTAModelIrfBackground::eval(const GEvent& event,
const GObservation& obs) const
{
// Get pointer on CTA observation
const GCTAObservation* cta = dynamic_cast<const GCTAObservation*>(&obs);
if (cta == NULL) {
std::string msg = "Specified observation is not a CTA observation.\n" +
obs.print();
throw GException::invalid_argument(G_EVAL, msg);
}
// Get pointer on CTA IRF response
const GCTAResponseIrf* rsp = dynamic_cast<const GCTAResponseIrf*>(cta->response());
if (rsp == NULL) {
std::string msg = "Specified observation does not contain an IRF response.\n" +
obs.print();
throw GException::invalid_argument(G_EVAL, msg);
}
// Retrieve pointer to CTA background
const GCTABackground* bgd = rsp->background();
if (bgd == NULL) {
std::string msg = "Specified observation contains no background"
" information.\n" + obs.print();
throw GException::invalid_argument(G_EVAL, msg);
}
// Extract CTA instrument direction from event
const GCTAInstDir* dir = dynamic_cast<const GCTAInstDir*>(&(event.dir()));
if (dir == NULL) {
std::string msg = "No CTA instrument direction found in event.";
throw GException::invalid_argument(G_EVAL, msg);
}
// Set DETX and DETY in instrument direction
GCTAInstDir inst_dir = cta->pointing().instdir(dir->dir());
// Evaluate function
double logE = event.energy().log10TeV();
double spat = (*bgd)(logE, inst_dir.detx(), inst_dir.dety());
double spec = (spectral() != NULL)
? spectral()->eval(event.energy(), event.time()) : 1.0;
double temp = (temporal() != NULL)
? temporal()->eval(event.time()) : 1.0;
// Compute value
double value = spat * spec * temp;
// Apply deadtime correction
value *= obs.deadc(event.time());
// Return value
return value;
}
/***********************************************************************//**
* @brief Evaluate function
*
* @param[in] event Observed event.
* @param[in] obs Observation.
* @return Function value.
*
* @exception GException::invalid_argument
* Specified observation is not of the expected type.
***************************************************************************/
double GCTAModelCubeBackground::eval(const GEvent& event,
const GObservation& obs) const
{
// Get pointer on CTA observation
const GCTAObservation* cta = dynamic_cast<const GCTAObservation*>(&obs);
if (cta == NULL) {
std::string msg = "Specified observation is not a CTA observation.";
throw GException::invalid_argument(G_EVAL, msg);
}
// Get pointer on CTA IRF response
const GCTAResponseCube* rsp = dynamic_cast<const GCTAResponseCube*>(cta->response());
if (rsp == NULL) {
std::string msg = "Specified observation does not contain a cube response.";
throw GException::invalid_argument(G_EVAL, msg);
}
// Extract CTA instrument direction from event
const GCTAInstDir* dir = dynamic_cast<const GCTAInstDir*>(&(event.dir()));
if (dir == NULL) {
std::string msg = "No CTA instrument direction found in event.";
throw GException::invalid_argument(G_EVAL, msg);
}
// Retrieve reference to CTA cube background
const GCTACubeBackground& bgd = rsp->background();
// Evaluate function
//double logE = event.energy().log10TeV();
double spat = bgd((*dir), event.energy());
double spec = (spectral() != NULL)
? spectral()->eval(event.energy(), event.time()) : 1.0;
double temp = (temporal() != NULL)
? temporal()->eval(event.time()) : 1.0;
// Compute value. Note that background rates are already per
// livetime, hence no deadtime correction is needed here.
double value = spat * spec * temp;
// Return value
return value;
}
/***********************************************************************//**
* @brief Evaluate function
*
* @param[in] event Observed event.
* @param[in] obs Observation.
* @return Function value.
*
* @exception GException::invalid_argument
* No CTA instrument direction found in event.
*
* Evaluates tha CTA background model which is a factorization of a
* spatial, spectral and temporal model component. This method also applies
* a deadtime correction factor, so that the normalization of the model is
* a real rate (counts/exposure time).
*
* @todo Add bookkeeping of last value and evaluate only if argument
* changed
***************************************************************************/
double GCTAModelBackground::eval(const GEvent& event,
const GObservation& obs) const
{
// Get pointer on CTA observation
const GCTAObservation* ctaobs = dynamic_cast<const GCTAObservation*>(&obs);
if (ctaobs == NULL) {
std::string msg = "Specified observation is not a CTA observation.\n" +
obs.print();
throw GException::invalid_argument(G_EVAL, msg);
}
// Extract CTA instrument direction
const GCTAInstDir* dir = dynamic_cast<const GCTAInstDir*>(&(event.dir()));
if (dir == NULL) {
std::string msg = "No CTA instrument direction found in event.";
throw GException::invalid_argument(G_EVAL, msg);
}
// Create a Photon from the event.
// We need the GPhoton to evaluate the spatial model.
// For the background, GEvent and GPhoton are identical
// since the IRFs are not folded in
GPhoton photon(dir->dir(), event.energy(), event.time());
// Evaluate function and gradients
double spat = (spatial() != NULL)
? spatial()->eval(photon) : 1.0;
double spec = (spectral() != NULL)
? spectral()->eval(event.energy(), event.time()) : 1.0;
double temp = (temporal() != NULL)
? temporal()->eval(event.time()) : 1.0;
// Compute value
double value = spat * spec * temp;
// Apply deadtime correction
value *= obs.deadc(event.time());
// Return
return value;
}
/***********************************************************************//**
* @brief Perform integration over spectral component
*
* @param[in] event Observed event.
* @param[in] srcTime True photon arrival time.
* @param[in] obs Observation.
* @param[in] grad Evaluate gradients.
*
* @exception GException::no_response
* Observation has no valid instrument response
* @exception GException::feature_not_implemented
* Energy integration not yet implemented
*
* This method integrates the source model over the spectral component. If
* the response function has no energy dispersion then no spectral
* integration is needed and the observed photon energy is identical to the
* true photon energy.
*
* @todo Needs implementation of spectral integration to handle energy
* dispersion.
***************************************************************************/
double GModelSky::spectral(const GEvent& event, const GTime& srcTime,
const GObservation& obs, bool grad) const
{
// Initialise result
double value = 0.0;
// Get response function
GResponse* rsp = obs.response();
if (rsp == NULL) {
throw GException::no_response(G_SPECTRAL);
}
// Determine if energy integration is needed
bool integrate = rsp->hasedisp();
// Case A: Integraion
if (integrate) {
throw GException::feature_not_implemented(G_SPECTRAL);
}
// Case B: No integration (assume no energy dispersion)
else {
value = spatial(event, event.energy(), srcTime, obs, grad);
}
// Compile option: Check for NaN/Inf
#if defined(G_NAN_CHECK)
if (isnotanumber(value) || isinfinite(value)) {
std::cout << "*** ERROR: GModelSky::spectral:";
std::cout << " NaN/Inf encountered";
std::cout << " (value=" << value;
std::cout << ", event=" << event;
std::cout << ", srcTime=" << srcTime;
std::cout << ")" << std::endl;
}
#endif
// Return value
return value;
}
/***********************************************************************//**
* @brief Evaluate function and gradients
*
* @param[in] event Observed event.
* @param[in] obs Observation.
* @return Function value.
*
* @exception GException::invalid_argument
* No CTA instrument direction found in event.
*
* Evaluates tha CTA background model and parameter gradients. The CTA
* background model is a factorization of a spatial, spectral and
* temporal model component. This method also applies a deadtime correction
* factor, so that the normalization of the model is a real rate
* (counts/exposure time).
*
* @todo Add bookkeeping of last value and evaluate only if argument
* changed
***************************************************************************/
double GCTAModelBackground::eval_gradients(const GEvent& event,
const GObservation& obs) const
{
// Get pointer on CTA observation
const GCTAObservation* ctaobs = dynamic_cast<const GCTAObservation*>(&obs);
if (ctaobs == NULL) {
std::string msg = "Specified observation is not a CTA observation.\n" +
obs.print();
throw GException::invalid_argument(G_EVAL_GRADIENTS, msg);
}
// Extract CTA instrument direction
const GCTAInstDir* dir = dynamic_cast<const GCTAInstDir*>(&(event.dir()));
if (dir == NULL) {
std::string msg = "No CTA instrument direction found in event.";
throw GException::invalid_argument(G_EVAL_GRADIENTS, msg);
}
// Create a Photon from the event
// We need the photon to evaluate the spatial model
// For the background, GEvent and GPhoton are identical
// since the IRFs are not folded in
GPhoton photon = GPhoton(dir->dir(), event.energy(),event.time());
// Evaluate function and gradients
double spat = (spatial() != NULL)
? spatial()->eval_gradients(photon) : 1.0;
double spec = (spectral() != NULL)
? spectral()->eval_gradients(event.energy(), event.time()) : 1.0;
double temp = (temporal() != NULL)
? temporal()->eval_gradients(event.time()) : 1.0;
// Compute value
double value = spat * spec * temp;
// Apply deadtime correction
double deadc = obs.deadc(event.time());
value *= deadc;
// Multiply factors to spatial gradients
if (spatial() != NULL) {
double fact = spec * temp * deadc;
if (fact != 1.0) {
for (int i = 0; i < spatial()->size(); ++i)
(*spatial())[i].factor_gradient( (*spatial())[i].factor_gradient() * fact );
}
}
// Multiply factors to spectral gradients
if (spectral() != NULL) {
double fact = spat * temp * deadc;
if (fact != 1.0) {
for (int i = 0; i < spectral()->size(); ++i)
(*spectral())[i].factor_gradient( (*spectral())[i].factor_gradient() * fact );
}
}
// Multiply factors to temporal gradients
if (temporal() != NULL) {
double fact = spat * spec * deadc;
if (fact != 1.0) {
for (int i = 0; i < temporal()->size(); ++i)
(*temporal())[i].factor_gradient( (*temporal())[i].factor_gradient() * fact );
}
}
// Return value
return value;
}
/***********************************************************************//**
* @brief Evaluate function
*
* @param[in] event Observed event.
* @param[in] obs Observation.
* @param[in] gradients Compute gradients?
* @return Function value.
*
* @exception GException::invalid_argument
* Specified observation is not of the expected type.
*
* If the @p gradients flag is true the method will also set the parameter
* gradients of the model parameters.
*
* @todo Make sure that DETX and DETY are always set in GCTAInstDir.
***************************************************************************/
double GCTAModelAeffBackground::eval(const GEvent& event,
const GObservation& obs,
const bool& gradients) const
{
// Get pointer on CTA observation
const GCTAObservation* cta = dynamic_cast<const GCTAObservation*>(&obs);
if (cta == NULL) {
std::string msg = "Specified observation is not a CTA observation.\n" +
obs.print();
throw GException::invalid_argument(G_EVAL, msg);
}
// Get pointer on CTA IRF response
const GCTAResponseIrf* rsp = dynamic_cast<const GCTAResponseIrf*>(cta->response());
if (rsp == NULL) {
std::string msg = "Specified observation does not contain an IRF response.\n" +
obs.print();
throw GException::invalid_argument(G_EVAL, msg);
}
// Retrieve pointer to CTA Effective Area
const GCTAAeff* aeff = rsp->aeff();
if (aeff == NULL) {
std::string msg = "Specified observation contains no effective area"
" information.\n" + obs.print();
throw GException::invalid_argument(G_EVAL, msg);
}
// Extract CTA instrument direction from event
const GCTAInstDir* dir = dynamic_cast<const GCTAInstDir*>(&(event.dir()));
if (dir == NULL) {
std::string msg = "No CTA instrument direction found in event.";
throw GException::invalid_argument(G_EVAL, msg);
}
// Set DETX and DETY in instrument direction
GCTAInstDir inst_dir = cta->pointing().instdir(dir->dir());
// Set theta and phi from instrument coordinates
double theta = std::sqrt(inst_dir.detx() * inst_dir.detx() +
inst_dir.dety() * inst_dir.dety());
double phi = gammalib::atan2d(inst_dir.dety(), inst_dir.detx()) *
gammalib::deg2rad;
// Evaluate function
double logE = event.energy().log10TeV();
double spat = (*aeff)(logE, theta, phi,
cta->pointing().zenith(),
cta->pointing().azimuth(), false);
double spec = (spectral() != NULL)
? spectral()->eval(event.energy(), event.time(), gradients)
: 1.0;
double temp = (temporal() != NULL)
? temporal()->eval(event.time(), gradients) : 1.0;
// Compute value
double value = spat * spec * temp;
// Apply deadtime correction
double deadc = obs.deadc(event.time());
value *= deadc;
// Optionally compute partial derivatives
if (gradients) {
// Multiply factors to spectral gradients
if (spectral() != NULL) {
double fact = spat * temp * deadc;
if (fact != 1.0) {
for (int i = 0; i < spectral()->size(); ++i)
(*spectral())[i].factor_gradient((*spectral())[i].factor_gradient() * fact );
}
}
// Multiply factors to temporal gradients
if (temporal() != NULL) {
double fact = spat * spec * deadc;
if (fact != 1.0) {
for (int i = 0; i < temporal()->size(); ++i)
(*temporal())[i].factor_gradient((*temporal())[i].factor_gradient() * fact );
}
}
} // endif: computed partial derivatives
// Return value
return value;
}
/***********************************************************************//**
* @brief Convolve sky model with the instrument response
*
* @param[in] model Sky model.
* @param[in] event Event.
* @param[in] obs Observation.
* @param[in] grad Should model gradients be computed? (default: true)
* @return Event probability.
*
* Computes the event probability
*
* \f[
* P(p',E',t') = \int \int \int
* S(p,E,t) \times R(p',E',t'|p,E,t) \, dp \, dE \, dt
* \f]
*
* without taking into account any time dispersion. Energy dispersion is
* correctly handled by this method. If time dispersion is indeed needed,
* an instrument specific method needs to be provided.
***************************************************************************/
double GResponse::convolve(const GModelSky& model,
const GEvent& event,
const GObservation& obs,
const bool& grad) const
{
// Set number of iterations for Romberg integration.
static const int iter = 6;
// Initialise result
double prob = 0.0;
// Continue only if the model has a spatial component
if (model.spatial() != NULL) {
// Get source time (no dispersion)
GTime srcTime = event.time();
// Case A: Integration
if (use_edisp()) {
// Retrieve true energy boundaries
GEbounds ebounds = this->ebounds(event.energy());
// Loop over all boundaries
for (int i = 0; i < ebounds.size(); ++i) {
// Get boundaries in MeV
double emin = ebounds.emin(i).MeV();
double emax = ebounds.emax(i).MeV();
// Continue only if valid
if (emax > emin) {
// Setup integration function
edisp_kern integrand(this, &obs, &model, &event, srcTime, grad);
GIntegral integral(&integrand);
// Set number of iterations
integral.fixed_iter(iter);
// Do Romberg integration
emin = std::log(emin);
emax = std::log(emax);
prob += integral.romberg(emin, emax);
} // endif: interval was valid
} // endfor: looped over intervals
}
// Case B: No integration (assume no energy dispersion)
else {
// Get source energy (no dispersion)
GEnergy srcEng = event.energy();
// Evaluate probability
prob = eval_prob(model, event, srcEng, srcTime, obs, grad);
}
// Compile option: Check for NaN/Inf
#if defined(G_NAN_CHECK)
if (gammalib::is_notanumber(prob) || gammalib::is_infinite(prob)) {
std::cout << "*** ERROR: GResponse::convolve:";
std::cout << " NaN/Inf encountered";
std::cout << " (prob=" << prob;
std::cout << ", event=" << event;
std::cout << ", srcTime=" << srcTime;
std::cout << ")" << std::endl;
}
#endif
} // endif: spatial component valid
// Return probability
return prob;
}