Bugs: confidence
Bugs
Confidence fails after fitting only background data; source model must also be set.
Currently, an attempt to run the confidence command after a fit to a background data set using fit_bkg, when no source model has been assigned to the associated source data set, will cause Sherpa to fail. This is a bug which will be addressed in a future release of the software, to allow the source and background data sets to be treated independently (as fit_bkg allows a background data set to be fit independently from its associated source data set).
sherpa> load_pha("source.pi")
sherpa> load_bkg("bkg.pi")
sherpa> set_bkg_model("xsphabs.abs1*powlaw1d.bkgp1")
sherpa> fit_bkg()
sherpa> conf(1,1)
IdentifierErr: model stack is empty
sherpa> set_model("xsphabs.abs1*powlaw1d.srcp1")
sherpa> conf(1,1)
abs1.nh lower bound: -0.00527305
bkgp1.gamma lower bound: -0.410748
bkgp1.gamma upper bound: 0.659292
bkgp1.ampl lower bound: -2.04293e-06
abs1.nh upper bound: 0.00672851
srcp1.gamma lower bound: -0.0750826
bkgp1.ampl upper bound: 4.28454e-06
srcp1.gamma upper bound: 0.0763327
srcp1.ampl lower bound: -1.24576e-05
srcp1.ampl upper bound: 1.28531e-05
Dataset = 1
Confidence Method = confidence
Iterative Fit Method = None
Fitting Method = levmar
Statistic = chi2gehrels
confidence 1-sigma (68.2689%) bounds:
Param Best-Fit Lower Bound Upper Bound
----- -------- ----------- -----------
abs1.nh 0.0178329 -0.00527305 0.00672851
srcp1.gamma 1.92493 -0.0750826 0.0763327
srcp1.ampl 0.000174607 -1.24576e-05 1.28531e-05
bkgp1.gamma -0.167417 -0.410748 0.659292
bkgp1.ampl 2.46545e-06 -2.04293e-06 4.28454e-06