Last modified: December 2023

URL: https://cxc.cfa.harvard.edu/sherpa/ahelp/get_covar.html
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AHELP for CIAO 4.16 Sherpa

get_covar

Context: confidence

Synopsis

Return the covariance estimation object.

Syntax

get_covar()

Examples

Example 1

>>> print(get_covar())
name        = covariance
sigma       = 1
maxiters    = 200
soft_limits = False
eps         = 0.01

Example 2

Change the sigma field to 1.9.

>>> cv = get_covar()
>>> cv.sigma = 1.6

Notes

The attributes of the covariance object include:

Item Definition
eps The precision of the calculated limits. The default is 0.01.
maxiters The maximum number of iterations allowed before stopping for that parameter. The default is 200.
sigma What is the error limit being calculated. The default is 1.
soft_limits Should the search be restricted to the soft limits of the parameters ( True ), or can parameter values go out all the way to the hard limits if necessary ( False ). The default is False

Bugs

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

See Also

confidence
conf, confidence, covar, covariance, get_conf, get_conf_results, 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, int_proj, int_unc, proj, projection, reg_proj, reg_unc, set_conf_opt, set_covar_opt, set_proj_opt
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
calc_stat_info, 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
get_analysis, get_rate
visualization
image_getregion