Gallery: Overplotting curves (S-Lang)

variable crv = ChipsCurve;
crv.line.style = "noline";
crv.symbol.style = "square";
crv.symbol.size = 3.0;
crv.symbol.fill = 0;
add_curve("spectrum.fits[data][cols x,y]",crv);
crv = ChipsCurve;
crv.symbol.style = "none";
crv.line.color = "red";
crv.line.thickness = 2;
add_curve("spectrum.fits[fit][cols x,y]",crv);
log_scale(XY_AXIS);

set_plot_xlabel("Energy (keV)");
set_plot_ylabel("Count s^{-1} keV^{-1}");
set_plot_title("Source spectrum");

set_xaxis({"offset.perpendicular",35});
set_plot({"leftmargin",0.25});
set_yaxis({"offset.perpendicular",45});

add_line(0.6,3.0e-4,0.9,3.0e-4,{"color","red","thickness",2});
add_label(1.0,3.0e-4,"Model",{"color","red","valign",0.5});

add_window(6.0,3.0);
variable crv = ChipsCurve;
crv.line.style = "noline";
crv.symbol.style = "square";
crv.symbol.size = 3.0;
crv.symbol.fill = 0;
add_curve("spectrum.fits[data][cols x,y,dylo,dyhi]",crv);
crv = ChipsCurve;
crv.symbol.style = "none";
crv.line.color = "red";
crv.line.thickness = 2;
add_curve("spectrum.fits[fit][cols x,y]",crv);
log_scale(XY_AXIS);
limits(X_AXIS,0.5,10.0);

set_plot_xlabel("Energy (keV)");
set_plot_ylabel("Count s^{-1} keV^{-1}");

set_xaxis({"offset.perpendicular",35});
set_plot({"leftmargin",0.15});
set_yaxis({"offset.perpendicular",45});