Last modified: December 2024

URL: https://cxc.cfa.harvard.edu/sherpa/ahelp/plot_bkg_delchi.html
AHELP for CIAO 4.17 Sherpa

plot_bkg_delchi

Context: plotting

Synopsis

Plot the ratio of residuals to error for the background of a PHA data set.

Syntax

plot_bkg_delchi(id=None, bkg_id=None, replot=False, overplot=False,
clearwindow=True, **kwargs)

Description

Display the ratio of the residuals (data-model) to the error values for the background of a PHA data set when it is being fit, rather than subtracted from the source.


Examples

Example 1

>>> plot_bkg_delchi()

Example 2

>>> plot_bkg_delchi('jet', bkg_id=1)
>>> plot_bkg_delchi('jet', bkg_id=2, overplot=True)

PARAMETERS

The parameters for this function are:

Parameter Type information Definition
id int, str, or None, optional The data set that provides the data. If not given then the default identifier is used, as returned by `get_default_id` .
bkg_id int, str, or None, optional Identify the background component to use, if there are multiple ones associated with the data set.
replot bool, optional Set to True to use the values calculated by the last call to `plot_bkg_ratio` . The default is False .
overplot bool, optional If True then add the data to an existing plot, otherwise create a new plot. The default is False .
clearwindow bool, optional Should the existing plot area be cleared before creating this new plot (e.g. for multi-panel plots)?

Notes

The ylog setting is ignored, and the Y axis is drawn using a linear scale.

Changes in CIAO

Changed in CIAO 4.12

The Y axis is now always drawn using a linear scale.


Bugs

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

See Also

contrib
get_data_prof, get_data_prof_prefs, get_delchi_prof, get_delchi_prof_prefs, get_fit_prof, get_model_prof, get_model_prof_prefs, get_resid_prof, get_resid_prof_prefs, get_source_prof, get_source_prof_prefs, plot_chart_spectrum, plot_marx_spectrum, prof_data, prof_delchi, prof_fit, prof_fit_delchi, prof_fit_resid, prof_model, prof_resid, prof_source
data
get_arf_plot, 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_source, get_bkg_source_plot, set_bkg, subtract, unsubtract
info
list_bkg_ids, show_bkg_model, show_bkg_source
modeling
delete_bkg_model, normal_sample, t_sample, uniform_sample
plotting
get_cdf_plot, get_energy_flux_hist, get_pdf_plot, get_photon_flux_hist, get_pvalue_plot, get_pvalue_results, get_split_plot, plot, plot_arf, plot_bkg, plot_bkg_chisqr, plot_bkg_fit, plot_bkg_fit_delchi, plot_bkg_fit_resid, plot_bkg_model, plot_bkg_ratio, plot_bkg_resid, plot_bkg_source, plot_cdf, plot_chisqr, plot_data, plot_delchi, plot_energy_flux, plot_fit, plot_fit_delchi, plot_fit_resid, plot_model, plot_model_component, plot_order, plot_pdf, plot_photon_flux, plot_pvalue, plot_ratio, plot_resid, plot_scatter, plot_source, plot_source_component, plot_trace, set_xlinear, set_xlog, set_ylinear, set_ylog
psfs
plot_kernel
statistics
get_chisqr_plot, get_delchi_plot
visualization
contour_resid