# plot_bkg_resid¶

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

Plot the residual (data-model) values for the background of a PHA data set.

Display the residuals for the background of a PHA data set when it is being fit, rather than subtracted from the source.

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_resid. 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_resid_plot()
Return the data used by plot_bkg_resid.
plot_bkg_chisqr()
Plot the chi-squared value for each point of the background of a PHA data set.
plot_bkg_delchi()
Plot the ratio of residuals to error for the background of a PHA data set.
plot_bkg_ratio()
Plot the ratio of data to model values for the background of a PHA data set.
set_bkg_model()
Set the background model expression for a PHA data set.

Examples

>>> plot_bkg_resid()

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