excess¶
-
gammapy.stats.excess(n_on, n_off, alpha)[source]¶ Estimate excess in the on region for an on-off observation.
\[\mu_{excess} = n_{on} - \alpha \times n_{off}\]- Parameters
- n_onarray_like
Observed number of counts in the on region
- n_offarray_like
Observed number of counts in the off region
- alphaarray_like
On / off region exposure ratio for background events
- Returns
- excess
numpy.ndarray Excess estimate for the on region
- excess
Examples
>>> excess(n_on=10, n_off=20, alpha=0.1) 8.0 >>> excess(n_on=4, n_off=9, alpha=0.5) -0.5