Andreas Specovius / ctools

Commit bc051b101bfaaa066644f382692f4765837a849f

Authored by Jürgen Knödlseder
1 parent 62f78c5d

Accelerate IRF and RING background methods in ctskymap (#2309)

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Showing 4 changed files with 46 additions and 65 deletions
ChangeLog
  View file @bc051b1
1   -2018-02-08
  1 +2018-02-10
2 2  
3 3 * Version 1.6.0 released
4 4 ========================
5 5  
  6 + Accelerate IRF and RING background methods in ctskymap (#2309)
  7 +
6 8  
7 9 * Bug fix version 1.5.1 released
8 10 ================================
... ...
1 1 New Features and Important Changes in ctools 1.6.0
2 2  
3   -8 February 2018
  3 +10 February 2018
4 4  
5 5  
6 6 Introduction
... ... @@ -106,7 +106,7 @@ None
106 106  
107 107 ctskymap - CTA sky mapping
108 108 --------------------------
109   -None
  109 +Accelerate the IRF and RING background methods (#2309).
110 110  
111 111  
112 112 cttsmap - Generation of Test Statistic map
... ...
doc/source/admin/release_history/1.6.rst
  View file @bc051b1
... ... @@ -22,7 +22,8 @@ Bug fixes
22 22 Improvements
23 23 ------------
24 24  
25   -* ...
  25 +* [`2309 <https://cta-redmine.irap.omp.eu/issues/2309>`_] -
  26 + Accelerate `IRF` and `RING` background methods in :ref:`ctskymap`
26 27  
27 28  
28 29 New features
... ...
src/ctskymap/ctskymap.cpp
  View file @bc051b1
1 1 /***************************************************************************
2 2 * ctskymap - Sky mapping tool *
3 3 * ----------------------------------------------------------------------- *
4   - * copyright (C) 2011-2017 by Juergen Knoedlseder *
  4 + * copyright (C) 2011-2018 by Juergen Knoedlseder *
5 5 * ----------------------------------------------------------------------- *
6 6 * *
7 7 * This program is free software: you can redistribute it and/or modify *
... ... @@ -30,7 +30,6 @@
30 30 #endif
31 31 #include <cstdio>
32 32 #include "ctskymap.hpp"
33   -#include "GSkyRegions.hpp"
34 33  
35 34 /* __ Method name definitions ____________________________________________ */
36 35 #define G_GET_PARAMETERS "ctskymap::get_parameter()"
... ... @@ -694,15 +693,14 @@ void ctskymap::map_background_irf(GCTAObservation* obs)
694 693 throw GException::invalid_value(G_MAP_BACKGROUND_IRF, msg);
695 694 }
696 695  
697   - // Compute natural logarithm of energy range in MeV
698   - double lnEmin = std::log(m_emin * 1.0e6);
699   - double lnEmax = std::log(m_emax * 1.0e6);
  696 + // Set minimum and maximum energy as GEnergy instances
  697 + GEnergy emin(m_emin, "TeV");
  698 + GEnergy emax(m_emax, "TeV");
700 699  
701 700 // Extract region of interest from observation
702 701 GCTARoi roi = obs->roi();
703 702  
704 703 // Initialise statistics
705   - int calls = 0;
706 704 double total = 0.0;
707 705  
708 706 // Loop over all background map pixels
... ... @@ -720,20 +718,9 @@ void ctskymap::map_background_irf(GCTAObservation* obs)
720 718 continue;
721 719 }
722 720  
723   - // Setup integration function
724   - ctskymap::irf_kern integrand(bkg, &instdir);
725   - GIntegral integral(&integrand);
  721 + // Compute background value
  722 + double value = bkg->rate_ebin(instdir, emin, emax);
726 723  
727   - // Set precision (has been carefully adjusted using a test simulation
728   - // over the energy range 20 GeV - 120 TeV)
729   - integral.eps(1.0e-6);
730   -
731   - // Do Romberg integration
732   - double value = integral.romberg(lnEmin, lnEmax);
733   -
734   - // Update number of background function calls
735   - calls += integral.calls();
736   -
737 724 // Multiply background rate with livetime and solid angle
738 725 value *= obs->livetime() * m_solidangle[i];
739 726  
... ... @@ -747,7 +734,6 @@ void ctskymap::map_background_irf(GCTAObservation* obs)
747 734  
748 735 // Log background subtraction results
749 736 log_value(NORMAL, "Events in background", int(total+0.5));
750   - log_value(NORMAL, "Background evaluations", calls);
751 737  
752 738 // Return
753 739 return;
... ... @@ -794,15 +780,14 @@ void ctskymap::map_background_ring(GCTAObservation* obs)
794 780 throw GException::invalid_value(G_MAP_BACKGROUND_RING, msg);
795 781 }
796 782  
797   - // Compute natural logarithm of energy range in MeV
798   - double lnEmin = std::log(m_emin * 1.0e6);
799   - double lnEmax = std::log(m_emax * 1.0e6);
  783 + // Set minimum and maximum energy as GEnergy instances
  784 + GEnergy emin(m_emin, "TeV");
  785 + GEnergy emax(m_emax, "TeV");
800 786  
801 787 // Extract region of interest from observation
802 788 GCTARoi roi = obs->roi();
803 789  
804   - // Initialise statistics
805   - int calls = 0;
  790 + // Extract exposure
806 791 double exposure = obs->livetime();
807 792  
808 793 // Loop over all map pixels
... ... @@ -820,30 +805,15 @@ void ctskymap::map_background_ring(GCTAObservation* obs)
820 805 continue;
821 806 }
822 807  
823   - // Setup integration function
824   - ctskymap::irf_kern integrand(bkg, &instdir);
825   - GIntegral integral(&integrand);
826   -
827   - // Set precision
828   - integral.eps(1.0e-6);
829   -
830   - // Do Romberg integration to get the sensitivity (note: this assumes
831   - // the background IRF is a good approximation for the radial
832   - // sensitivity)
833   - m_alphamap(i,0) += integral.romberg(lnEmin, lnEmax) *
  808 + // Compute background value
  809 + m_alphamap(i,0) += bkg->rate_ebin(instdir, emin, emax) *
834 810 m_solidangle[i] * exposure;
835 811  
836 812 // Store the counts in this bin
837 813 m_onmap(i,0) += m_skymap(i,0);
838 814  
839   - // Update number of background function calls
840   - calls += integral.calls();
841   -
842 815 } // endfor: Loop for caching bkg IRF sensitivity
843 816  
844   - // Log background subtraction results
845   - log_value(NORMAL, "Alpha map evaluations", calls);
846   -
847 817 // Zero out the counts map to prepare it for the next observation
848 818 m_skymap = 0.0;
849 819  
... ... @@ -995,10 +965,14 @@ void ctskymap::compute_ring_values(const GSkyMap&amp; counts,
995 965 double alpha_on = 0.0;
996 966 double alpha_off = 0.0;
997 967  
998   - // Define the regions necessary to do the pixel checks
999   - GSkyRegionCircle roi_reg(position, m_roiradius);
1000   - GSkyRegionCircle inner_reg(position, m_inradius);
1001   - GSkyRegionCircle outer_reg(position, m_outradius);
  968 + // Compute cosine of radii. We use the cosine of the radius here to
  969 + // mimimize as much as possible the trigonometric computations. Note that
  970 + // the cosine of an angle is maximal for an angle of zero. This explains
  971 + // later why we chose ">=" to test whether an angle is smaller than a
  972 + // given radius.
  973 + double cos_roiradius = std::cos(m_roiradius * gammalib::deg2rad);
  974 + double cos_inradius = std::cos(m_inradius * gammalib::deg2rad);
  975 + double cos_outradius = std::cos(m_outradius * gammalib::deg2rad);
1002 976  
1003 977 // Loop over every pixel in the observation to compute Non, Noff
1004 978 for (int j = 0; j < counts.npix(); ++j) {
... ... @@ -1006,28 +980,32 @@ void ctskymap::compute_ring_values(const GSkyMap&amp; counts,
1006 980 // Get the index and sky direction of this pixel
1007 981 GSkyDir& skydir = m_dirs[j];
1008 982  
1009   - // Check if pixel is inside the background region
1010   - if ((m_exclmap(j,0) == 0.0) && outer_reg.contains(skydir) &&
1011   - !inner_reg.contains(skydir)) {
  983 + // Only consider pixels within the outer radius of the background region
  984 + if (position.cos_dist(skydir) >= cos_outradius) {
1012 985  
1013   - // Update n_off
1014   - noff += counts(j,0);
  986 + // Check if pixel is inside the background region
  987 + if ((m_exclmap(j,0) == 0.0) && position.cos_dist(skydir) < cos_inradius) {
1015 988  
1016   - // Update alpha_off
1017   - alpha_off += sensitivity(j,0);
  989 + // Update n_off
  990 + noff += counts(j,0);
1018 991  
1019   - }
  992 + // Update alpha_off
  993 + alpha_off += sensitivity(j,0);
  994 +
  995 + }
  996 +
  997 + // ... otherwise check if pixel is inside source region
  998 + else if (position.cos_dist(skydir) >= cos_roiradius) {
1020 999  
1021   - // ... otherwise check if pixel is inside source region
1022   - else if (roi_reg.contains(skydir)) {
  1000 + // Update n_on for significance computation
  1001 + non += counts(j,0);
1023 1002  
1024   - // Update n_on for significance computation
1025   - non += counts(j,0);
  1003 + // Update alpha_on
  1004 + alpha_on += sensitivity(j,0);
1026 1005  
1027   - // Update alpha_on
1028   - alpha_on += sensitivity(j,0);
  1006 + } // endif: source and background region check
1029 1007  
1030   - } // endif: source and background region check
  1008 + } // endif: pixel is within outer radius of background region
1031 1009  
1032 1010 } // endfor: looped over pixels
1033 1011  
... ...