plot_bkg

plot_bkg( [id]; [bkg_id=NULL, replot=0, overplot=0] );
plot_bkg_chisqr( [id]; [bkg_id=NULL, replot=0, overplot=0] );
plot_bkg_delchi( [id]; [bkg_id=NULL, replot=0, overplot=0] );
plot_bkg_fit( [id]; [bkg_id=NULL, replot=0, overplot=0] );
plot_bkg_fit_delchi( [id]; [bkg_id=NULL, replot=0, overplot=0] );
plot_bkg_fit_resid( [id]; [bkg_id=NULL, replot=0, overplot=0] );
plot_bkg_model( [id]; [bkg_id=NULL, replot=0, overplot=0] );
plot_bkg_ratio( [id]; [bkg_id=NULL, replot=0, overplot=0] );
plot_bkg_resid( [id]; [bkg_id=NULL, replot=0, overplot=0] );
plot_bkg_source( [id]; [lo=NULL, hi=NULL, bkg_id=NULL, replot=0,
overplot=0] );
plot_bkg_unconvolved( [id]; [lo=NULL, hi=NULL, bkg_id=NULL, replot=0,
overplot=0] );

Description

There are a number of commands to plot information about the background data:

• plot_bkg - background counts
• plot_bkg_chisqr - background chi squared contributions
• plot_bkg_delchi - background delta chi (residuals divided by background uncertainties)
• plot_bkg_fit - background counts with fitted background model
• plot_bkg_fit_delchi - background fit and background delta chi
• plot_bkg_fit_resid - background fit and background residuals
• plot_bkg_model - convolved background model
• plot_bkg_ratio - background ratio (background measured counts divided by background predicted counts)
• plot_bkg_resid - background residuals (measured background counts minus predicted background counts)
• plot_bkg_source - unconvolved source model; may also be called as plot_bkg_unconvolved

The commands take the following options:

• id - the id of the dataset to use; if not given, uses the default dataset id (id=1 by default, see "ahelp get_default_id")
• bkg_id - the id of the background to use, e.g. if more than one background is associated with the data; default is the first background dataset
• lo - lower bound of the desired plotting range; default=Null
• hi - high bound of the desired plotting range; default= Null
• lo - (plot_bkg_source only) lower limit of the plot in the same units as the data (energy [keV] or wavelength [A]); default=NULL, which uses the value from the response file (ENERG_LO)
• hi - (plot_bkg_source only) upper limit of the plot in the same units as the data (energy [keV] or wavelength [A]); default=NULL, which uses the value from the response file (ENERG_HI)
• overplot - should the new plot be overlaid in the plotting window? 0 (default)=clear the window, 1=overplot on any existing plots

The plot is displayed in a ChIPS plotting window. If there is no plotting window open, one is created. If a plotting window exists, the overplot parameter value determines whether the new plot is overlaid on any existing plots in the window or if the window is cleared before the plot is drawn.

ChIPS commands may be used within Sherpa to modify plot characteristics and create hardcopies; refer to the ChIPS website for information.

sherpa> plot_bkg();

sherpa> plot_bkg("src"; bkg_id="bg2", overplot=1);