get_bkg_fit_plot¶
-
sherpa.astro.ui.
get_bkg_fit_plot
(id=None, bkg_id=None, recalc=True)¶ Return the data used by plot_bkg_fit.
- 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.
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.
- Returns
model – An object representing the data used to create the plot by plot_bkg_fit.
- Return type
a sherpa.astro.plot.BkgFitPlot instance
- Raises
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.
See also
get_bkg_plot
Return the data used by plot_bkg.
get_bkg_model_plot
Return the data used by plot_bkg_model.
plot_bkg_fit
Plot the fit results (data, model) for the background of a PHA data set.
Examples
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)