add AEFF2D example file

source/irfs/effective_area/create_example_file.py

@@ -0,0 +1,39 @@
+"""This script generates an example effective area
+
+It complies to the specifications at http://gamma-astro-data-formats.readthedocs.org/en/latest/irfs/effective_area/index.html
+"""
+
+from astropy.io import fits
+from astropy.table import Table
+import numpy as np
+
+e_bins = 20
+o_bins = 5
+e_axis = np.logspace(-1,2,e_bins+1)
+o_axis = np.linspace(0,3,o_bins+1)
+effarea = np.ones([e_bins, o_bins]) * 3e5
+
+table = Table([[e_axis[:-1]],[e_axis[1:]],
+               [o_axis[:-1]],[o_axis[1:]],
+               [effarea]],
+              names=('ENERG_LO', 'ENERG_HI',
+                     'THETA_LO', 'THETA_HI',
+                     'EFFAREA'))
+
+data = table.as_array()
+header = fits.Header()
+header['OBS_ID'] = 31415 , 'Observation ID'
+header['LO_THRES'] = 0.1 , 'Low energy threshold [TeV]'
+header['HI_THRES'] = 50 , 'High energy threshold [TeV]'
+header['RAD_MAX'] = 0.1, 'On region radius for point-like observations'
+
+tbhdu = fits.BinTableHDU(data, header, name='EFFECTIVE AREA')
+
+for colname in table.colnames:
+    tbhdu.columns[colname].unit = str(table[colname].unit)
+
+prihdu = fits.PrimaryHDU()
+
+thdulist = fits.HDUList([prihdu, tbhdu])
+thdulist.writeto('aeff_2d_example.fits', clobber=True)
+

source/irfs/effective_area/index.rst

@@ -47,6 +47,8 @@ Columns:
 
 Header keywords:
 
+* ``OBS_ID`` type: int
+    * Observation ID, run number
 * ``LO_THRES`` type: float, unit: TeV
     * Low energy threshold
 * ``HI_THRES`` type: float, unit: TeV