calculate_sensitivity
- pyirf.sensitivity.calculate_sensitivity(signal_hist, background_hist, alpha, min_significance=5, min_signal_events=10, min_excess_over_background=0.05, significance_function=<function li_ma_significance>)[source]
Calculate sensitivity for DL2 event lists in bins of reconstructed energy.
Sensitivity is defined as the minimum flux detectable with
target_significance
sigma significance in a certain time.This time must be incorporated into the event weights.
Two conditions are required for the sensitivity: - At least ten weighted signal events - The weighted signal must be larger than 5 % of the weighted background - At least 5 sigma (so relative_sensitivity > 1)
If the conditions are not met, the sensitivity will be set to nan.
- Parameters:
- signal_hist: astropy.table.QTable
Histogram of detected signal events as a table. Required columns: n and n_weighted. See
pyirf.binning.create_histogram_table
- background_hist: astropy.table.QTable
Histogram of detected events as a table. Required columns: n and n_weighted. See
pyirf.binning.create_histogram_table
- alpha: float
Size ratio of signal region to background region
- min_significance: float
Significance necessary for a detection
- min_signal_events: int
Minimum number of signal events required. The relative flux will be scaled up from the one yielding
min_significance
if this condition is violated.- min_excess_over_background: float
Minimum number of signal events expressed as the proportion of the background. So the required number of signal events will be
min_excess_over_background * alpha * n_off
. The relative flux will be scaled up from the one yieldingmin_significance
if this condition is violated.- significance_function: callable
A function with signature (n_on, n_off, alpha) -> significance. Default is the Li & Ma likelihood ratio test.
- Returns:
- sensitivity_table: astropy.table.QTable
Table with sensitivity information. Contains weighted and unweighted number of signal and background events and the
relative_sensitivity
, the scaling applied to the signal events that yieldstarget_significance
sigma of significance according to thesignificance_function