Last modified: December 2020

URL: https://cxc.cfa.harvard.edu/sherpa/ahelp/calc_stat_info.html
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AHELP for CIAO 4.13 Sherpa v1

calc_stat_info

Context: fitting

Synopsis

Display the statistic values for the current models.

Syntax

calc_stat_info()

Description

Displays the statistic value for each data set, and the combined fit, using the current set of models, parameters, and ranges. The output is printed to stdout, and so is intended for use in interactive analysis. The `get_stat_info` function returns the same information but as an array of Python structures.


Example

>>> calc_stat_info()

Notes

If a fit to a particular data set has not been made, or values - such as parameter settings, the noticed data range, or choice of statistic - have been changed since the last fit, then the results for that data set may not be meaningful and will therefore bias the results for the simultaneous results.

The information returned by `calc_stat_info` includes:

Item Definition
Dataset The dataset identifier (or identifiers).
Statistic The name of the statistic used to calculate the results.
Fit statistic value The current fit statistic value.
Data points The number of bins used in the fit.
Degrees of freedom The number of bins minus the number of thawed parameters.

Some fields are only returned for a subset of statistics:

Item Definition
Probability (Q-value) A measure of the probability that one would observe the reduced statistic value, or a larger value, if the assumed model is true and the best-fit model parameters are the true parameter values.
Reduced statistic The fit statistic value divided by the number of degrees of freedom.

Bugs

See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.

See Also

confidence
get_conf, get_conf_results, get_covar, get_covar_opt, get_covar_results, get_covariance_results, get_int_proj, get_int_unc, get_proj, get_proj_opt, get_proj_results, get_projection_results, get_reg_proj, get_reg_unc
contrib
get_chart_spectrum, get_marx_spectrum
data
get_areascal, get_arf, get_arf_plot, get_axes, get_backscal, get_bkg, get_bkg_arf, get_bkg_chisqr_plot, get_bkg_delchi_plot, get_bkg_fit_plot, get_bkg_model, get_bkg_model_plot, get_bkg_plot, get_bkg_ratio_plot, get_bkg_resid_plot, get_bkg_rmf, get_bkg_scale, get_bkg_source, get_bkg_source_plot, get_coord, get_counts, get_data, get_data_contour, get_data_contour_prefs, get_data_image, get_data_plot, get_data_plot_prefs, get_dep, get_dims, get_error, get_exposure, get_grouping, get_indep, get_quality, get_rmf, get_specresp, get_staterror, get_syserror
filtering
get_filter
fitting
get_stat_info
info
get_default_id, list_stats
methods
get_draws, get_iter_method_name, get_iter_method_opt, get_method, get_method_name, get_method_opt
modeling
get_model, get_model_component, get_model_component_image, get_model_component_plot, get_model_plot, get_num_par, get_num_par_frozen, get_num_par_thawed, get_order_plot, get_par, get_pileup_model, get_response, get_source, get_source_component_image, get_source_component_plot, get_source_contour, get_source_image, get_source_plot, image_source
plotting
get_split_plot
psfs
get_psf, get_psf_contour, get_psf_image, get_psf_plot
statistics
get_chisqr_plot, get_delchi_plot, get_prior, get_sampler, get_stat, get_stat_name
utilities
calc_stat, get_analysis, get_rate
visualization
image_getregion