How can I plot my data in units of Counts versus Energy(keV)?

By default, Sherpa plots PHA data in units of Counts s^-1keV^-1 versus Energy(keV) when the chosen units for the spectral analysis is 'energy' ('set_analysis("energy")'). In order to plot data in Counts versus Energy(keV), change the unit type for the y-axis of a plot to "counts" with the set_analysis 'type' option, and set the 'factor' option to 0:

sherpa> set_analysis(2, "energy", "counts", factor=0)

This command sets the unit type for the axes of plots produced for data set 2, Energy (keV) for the x-axis and Counts for the y-axis. A 'factor' setting of 1 will produce plots in units of Counts*Energy(keV) versus Energy(keV), and a 'factor' setting of 2 will produce plots in units of Counts*Energy²(keV) versus Energy(keV).