cash#
- gammapy.stats.cash(n_on, mu_on, truncation_value=1e-25)[source]#
Cash statistic, for Poisson data.
The Cash statistic is defined as:
\[C = 2 \left( \mu_{on} - n_{on} \log \mu_{on} \right)\]and \(C = 0\) where \(\mu <= 0\). For more information see Fit statistics
- Parameters
- n_onarray_like
Observed counts
- mu_onarray_like
Expected counts
- truncation_valuearray_like
Minimum value use for
mu_on
mu_on
=truncation_value
wheren_on
<=truncation_value
Default is 1e-25.
- Returns
- statndarray
Statistic per bin
References