FitResults

class sherpa.fit.FitResults(fit, results, init_stat, param_warnings)[source] [edit on github]

Bases: sherpa.utils.NoNewAttributesAfterInit

The results of a fit.

This object contains the parameter values, information on the statistic and optimisation-method used, and other relevant information.

Changed in version 4.10.1: The covarerr attribute has been renamed to covar and now contains the covariance matrix estimated at the best-fit location, if provided by the optimiser.

datasets

A sequence of the data set ids included in the results.

Type:sequence of int or str, or None
itermethodname

What iterated-fit scheme was used, if any.

Type:str or None
methodname

The name of the optimisation method used (in lower case).

Type:str
statname

The name of the statistic function.

Type:str
succeeded

Was the fit successful (did it converge)?

Type:bool
parnames

the parameter names that were varied in the fit (the thawed parameters in the model expression).

Type:tuple of str
parvals

The parameter values, in the same order as parnames.

Type:tuple of number
statval

The statistic value after the fit.

Type:number
istatval

The statistic value at the start of the fit.

Type:number
dstatval

The change in the statistic value (istatval - statval).

Type:number
numpoints

The number of bins used in the fits.

Type:int
dof

The number of degrees of freedom in the fit (the number of bins minus the number of free parameters).

Type:int
qval

The Q-value (probability) that one would observe the reduced statistic value, or a larger value, if the assumed model is true and the current model parameters are the true parameter values. This will be None if the value can not be calculated with the current statistic (e.g. the Cash statistic).

Type:number or None
rstat

The reduced statistic value (the statval field divided by dof). This is not calculated for all statistics.

Type:number or None
message

A message about the results of the fit (e.g. if the fit was unable to converge). The format and contents depend on the optimisation method.

Type:str
nfev

The number of model evaluations made during the fit.

Type:int
extra_output

The extra_output field from the fit.

covar

The covariance matrix from the best-fit location, if provided by the optimiser.

Type:tuple or None
modelvals

The values of the best-fit model evaluated for the data.

Type:NumPy array

Methods Summary

format() Return a string representation of the fit results.

Methods Documentation

format()[source] [edit on github]

Return a string representation of the fit results.

Returns:txt – A multi-line representation of the fit results.
Return type:str