Ejemplo n.º 1
0
/***********************************************************************//**
 * @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;
}
Ejemplo n.º 2
0
/***********************************************************************//**
 * @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;
}
Ejemplo n.º 3
0
/***********************************************************************//**
 * @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;
}