Include endpoint in create_bins_per_decade if it matches the regular …

…spacing, fixes #187

pyirf/binning.py

@@ -98,7 +98,9 @@ def create_bins_per_decade(e_min, e_max, bins_per_decade=5):
     e_min: u.Quantity[energy]
         Minimum energy, inclusive
     e_max: u.Quantity[energy]
-        Maximum energy, exclusive
+        Maximum energy, non-inclusive
+        If the endpoint exactly matches the ``n_bins_per_decade`` requirement,
+        it will be included.
     n_bins_per_decade: int
         number of bins per decade
 
@@ -112,7 +114,10 @@ def create_bins_per_decade(e_min, e_max, bins_per_decade=5):
     log_lower = np.log10(e_min.to_value(unit))
     log_upper = np.log10(e_max.to_value(unit))
 
-    bins = 10 ** np.arange(log_lower, log_upper, 1 / bins_per_decade)
+    step = 1 / bins_per_decade
+    # include endpoint if reasonably close
+    eps = step / 10000
+    bins = 10 ** np.arange(log_lower, log_upper + eps, step)
     return u.Quantity(bins, e_min.unit, copy=False)
 
 

pyirf/tests/test_binning.py

@@ -45,18 +45,25 @@ def test_bins_per_decade():
     bins = create_bins_per_decade(100 * u.GeV, 100 * u.TeV)
 
     assert bins.unit == u.GeV
-    assert len(bins) == 15  # end non-inclusive
+    assert len(bins) == 16  # end inclusive if exactly fits per_decade
 
     assert bins[0] == 100 * u.GeV
     assert np.allclose(np.diff(np.log10(bins.to_value(u.GeV))), 0.2)
 
     bins = create_bins_per_decade(100 * u.GeV, 100 * u.TeV, 10)
     assert bins.unit == u.GeV
-    assert len(bins) == 30  # end non-inclusive
+    assert len(bins) == 31  # end inclusive since it fits exactly
 
     assert bins[0] == 100 * u.GeV
     assert np.allclose(np.diff(np.log10(bins.to_value(u.GeV))), 0.1)
 
+    bins = create_bins_per_decade(100 * u.GeV, 105 * u.TeV, 5)
+    assert bins.unit == u.GeV
+    assert len(bins) == 16  # end non-inclusive
+
+    assert u.isclose(bins[-1], 100 * u.TeV) # last value at correct difference
+    assert np.allclose(np.diff(np.log10(bins.to_value(u.GeV))), 0.2)
+
 
 def test_create_histogram_table():
     '''Test create histogram table'''