weight
change weighting used in computing statistic
Change the weighting function used in the calculation of chi-squared.
Syntax: | weight | [standard | gehrels | churazov | model] |
---|
standard weighting uses or the statistical error given in
the input spectrum. gehrels weighting uses
,
a better approximation when N is small (Gehrels, N. 1986, ApJ 303, 336).
churazov weighting uses the suggestion of Churazov et al.
(1996, ApJ 471, 673) to estimate the weight for a given channel by averaging
the counts in surrounding channels. model weighting uses the value of
the model, not the data, to estimate the weight.