Synopsis
Chi-square statistic with variance computed from data amplitudes.
Description
The chi2xspecvar statistic is equivalent to chi2datavar ("ahelp chi2datavar"), except that when the number of counts in a channel bin is less than 1, the variance is set to 1.
Example
sherpa> set_stat("chi2xspecvar")
sherpa> show_stat()
Statistic: Chi2XspecVarSet the fitting statistic and then confirm the new value.
Bugs
See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.
See Also
- info
- list_stats
- statistics
- cash, chi2constvar, chi2datavar, chi2gehrels, chi2modvar, chisquare, cstat, get_prior, leastsq, list_priors, set_prior, set_sampler, set_stat, wstat