Fix bug where single detector event fit_threshold was being read from…

… wrong location (#4971)

examples/live/make_singles_significance_fits.py

@@ -21,7 +21,6 @@
 # Set attributes to be something appropriate
 f.attrs['start_date'] = 0
 f.attrs['end_date'] = n_days
-f.attrs['fit_threshold'] = 6.5
 
 f['bins_edges'] = np.logspace(np.log10(min_duration),
                               np.log10(max_duration),
@@ -35,6 +34,7 @@
     ifo_group.attrs['live_time'] = np.round(n_days * 0.7 * 86400.)
     ifo_group.attrs['mean_alpha'] = alpha
     ifo_group.attrs['total_counts'] = daily_counts_per_bin * n_days * n_bins
+    ifo_group.attrs['fit_threshold'] = 6.5
 
     # Make daily fits datasets, this doesn't atually matter for the test, but
     # means that the file format matches in case of future requirements

pycbc/events/single.py

@@ -320,7 +320,7 @@ def calculate_ifar(self, sngl_ranking, duration):
             with HFile(self.fit_file, 'r') as fit_file:
                 bin_edges = fit_file['bins_edges'][:]
                 live_time = fit_file[self.ifo].attrs['live_time']
-                thresh = fit_file.attrs['fit_threshold']
+                thresh = fit_file[self.ifo].attrs['fit_threshold']
                 dist_grp = fit_file[self.ifo][self.sngl_ifar_est_dist]
                 rates = dist_grp['counts'][:] / live_time
                 coeffs = dist_grp['fit_coeff'][:]