# plot_bkg_fit_ratio¶

sherpa.astro.ui.plot_bkg_fit_ratio(id=None, bkg_id=None, replot=False, overplot=False, clearwindow=True, **kwargs)

Plot the fit results, and the data/model ratio, for the background of a PHA data set.

This creates two plots - the first from plot_bkg_fit and the second from plot_bkg_ratio - for a data set.

New in version 4.12.0.

Parameters: id (int or str, 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 or str, 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_fit_ratio. The default is False. overplot (bool, optional) – If True then add the data to an exsiting 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)? sherpa.utils.err.ArgumentErr – If the data set does not contain PHA data. sherpa.utils.err.IdentifierErr – If the bkg_id parameter is invalid. sherpa.utils.err.ModelErr – If no model expression has been created for the background data.

get_bkg_fit_plot()
Return the data used by plot_bkg_fit.
get_bkg_resid_plot()
Return the data used by plot_bkg_resid.
plot()
Create one or more plot types.
plot_bkg()
Plot the background values for a PHA data set.
plot_bkg_model()
Plot the model for the background of a PHA data set.
plot_bkg_fit()
Plot the fit results (data, model) for the background of a PHA data set.
plot_bkg_fit_delchi()
Plot the fit results, and the residuals, for the background of a PHA data set.
plot_bkg_fit_resid()
Plot the fit results, and the residuals, for the background of a PHA data set.
plot_fit()
Plot the fit results (data, model) for a data set.
plot_fit_resid()
Plot the fit results, and the residuals, for a data set.
set_analysis()
Set the units used when fitting and displaying spectral data.

Examples

Plot the background fit and the ratio of the background to this fit for the default data set:

>>> plot_bkg_fit_ratio()