sherpa.astro.ui.get_bkg_fit_plot(id=None, bkg_id=None, recalc=True)

Return the data used by plot_bkg_fit.

  • 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.

  • recalc (bool, optional) – If False then the results from the last call to plot_bkg_fit (or get_bkg_fit_plot) are returned, otherwise the data is re-generated.


model – An object representing the data used to create the plot by plot_bkg_fit.

Return type:

a sherpa.astro.plot.BkgFitPlot instance


See also


Return the data used by plot_bkg.


Return the data used by plot_bkg_model.


Plot the fit results (data, model) for the background of a PHA data set.


Create the data needed to create the “fit plot” for the background of the default data set and display it:

>>> bplot = get_bkg_fit_plot()
>>> print(bplot)

Return the plot data for data set 2, and then use it to create a plot:

>>> b2 = get_bkg_fit_plot(2)
>>> b2.plot()

The fit plot consists of a combination of a data plot and a model plot, which are captured in the dataplot and modelplot attributes of the return value. These can be used to display the plots individually, such as:

>>> b2.dataplot.plot()
>>> b2.modelplot.plot()

or, to combine the two:

>>> b2.dataplot.plot()
>>> b2.modelplot.overplot()

Return the plot data for the second background component to the “jet” data set:

>>> bplot = get_bkg_fit_plot('jet', bkg_id=2)