plot_bkg_delchi

sherpa.astro.ui.plot_bkg_delchi(id=None, bkg_id=None, **kwargs)

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

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.

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_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.
Raises:

See also

get_bkg_delchi_plot()
Return the data used by plot_bkg_delchi.
plot_bkg_chisqr()
Plot the chi-squared value for each point of 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.
plot_bkg_resid()
Plot the residual (data-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_delchi()
>>> plot_bkg_delchi('jet', bkg_id=1)
>>> plot_bkg_delchi('jet', bkg_id=2, overplot=True)