cstat#
- gammapy.stats.cstat(n_on, mu_on, truncation_value=1e-25)[source]#
C statistic, for Poisson data.
The C statistic is defined as
\[C = 2 \left[ \mu_{on} - n_{on} + n_{on} (\log(n_{on}) - log(\mu_{on}) \right]\]and \(C = 0\) where \(\mu_{on} <= 0\).
truncation_value
handles the case wheren_on
ormu_on
is 0 or less and the log cannot be taken. For more information see Fit statistics- Parameters
- n_onarray_like
Observed counts
- mu_onarray_like
Expected counts
- truncation_valuearray_like
n_on
=truncation_value
wheren_on
<=truncation_value.
mu_on
=truncation_value
wheren_on
<=truncation_value
Default is 1e-25.
- Returns
- statndarray
Statistic per bin
References