If G is a spectra object then G.Shift($\omega_0$) shifts the energy of the spectrum i.e. Gnew($\omega$) = G($\omega$-$\omega_0$). G.Shift is similar to the function Spectra.Shift with the difference that it does not make a copy of the spectra object.
Take the spectrum defined in the file definitions.Quanty and shift it by 5.3 eV.
dofile("definitions.Quanty") G.Print({{"file","Spectra.dat"}}) G.Shift(5.3) G.Print({{"file","Spectra.Shift.dat"}}) gnuplotScript = gnuplotHead .. [[ set output "Spectra.Shift.ps" plot "Spectra.dat" using 1:(-$3 ) title 'T1' with lines ls 1,\ "Spectra.Shift.dat" using 1:(-$3) title 'T1 shifted' with lines ls 2 ]] file = io.open("Spectra.Shift.gnuplot", "w") file:write(gnuplotScript) file:close() os.execute("gnuplot Spectra.Shift.gnuplot") os.execute("convert -density 1024 Spectra.Shift.ps -resize 1024 Spectra.Shift.png")
The resulting picture is: