Add script to show spectral model

Jürgen Knödlseder
1 parent f871c5c8
Showing 2 changed files with 92 additions and 0 deletions
examples/README
examples/show_model.py
@@ -59,6 +59,9 @@ pipeline_unbinned_mem.py
 show_butterfly.py
   Displays a butterfly generated using the ctbutterfly tool.
  
+show_model.py
+  Displays a spectral model.
+
 show_pha.py
   Displays a spectrum in PHA format.
  
+#! /usr/bin/env python
+# ==========================================================================
+# This script shows a model 
+#
+# Copyright (C) 2015 Juergen Knoedlseder
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# ==========================================================================
+import gammalib
+import sys
+try:
+    import matplotlib.pyplot as plt
+except:
+    sys.exit("This script needs matplotlib")
+
+
+# ======================= #
+# Plot spectral component #
+# ======================= #    
+def plot_spectrum(model, emin=0.01, emax=100.0, enumbins=100):
+    """
+    """
+    # Get spectral component
+    spectrum = model.spectral()
+  
+    # Setup energy axis
+    e_min   = gammalib.GEnergy(emin, "TeV")
+    e_max   = gammalib.GEnergy(emax, "TeV")
+    ebounds = gammalib.GEbounds(enumbins, e_min, e_max)
+
+    # Setup model plot
+    x = []
+    y = []
+    for i in range(enumbins):
+        energy = ebounds.elogmean(i)
+        x.append(energy.TeV())
+        y.append(spectrum.eval(energy, gammalib.GTime()))
+
+    # Show spectrum
+    plt.figure()
+    plt.title(model.name())
+    plt.loglog()
+    plt.grid()
+    plt.loglog(x, y, color='red')
+    plt.xlabel("Energy [TeV]")
+    plt.ylabel(r"dN/dE [ph s$^{-1}$ cm$^{-2}$ MeV$^{-1}$]")    
+    plt.show()
+    
+    # Return
+    return
+    
+    
+# ============= #
+# Script entry  #
+# ============= #    
+if __name__ == "__main__":
+    """
+    """
+    # Check for model filename
+    if len(sys.argv) < 2:
+        sys.exit("Usage: show_model.py model.xml [index]")
+
+    # Get optional model index
+    if len(sys.argv) == 3:
+        index = int(sys.argv[2])
+    else:
+        index = 0
+
+    # Read models XML file
+    filename = sys.argv[1]
+    models   = gammalib.GModels(filename)
+
+    # Extract relevant model
+    model = models[index]
+    
+    # Plot spectrum
+    plot_spectrum(model)