def expansion(Xref, Xav, gamma, used_params, allrasd, surface, parameter, parameter_usage, use_bulk_water, Refine_Data, use_lay_el):
Xexp = (1+gamma)*Xref - gamma*Xav
Xexp = check_limits(used_params, Xexp, parameter)
parameter = insert(used_params, Xexp, parameter)
allrasd = Rasd_difference(allrasd, surface, parameter, parameter_usage, use_bulk_water, Refine_Data, use_lay_el)
Yexp = allrasd.RMS
return Xexp, Yexp
def reflection(Xmax, Xav, alpha, used_params, allrasd, surface, parameter, parameter_usage, use_bulk_water, Refine_Data, use_lay_el):
Xref = (1+alpha)*Xav - alpha*Xmax
Xref = check_limits(used_params, Xref, parameter)
parameter = insert(used_params, Xref, parameter)
allrasd = Rasd_difference(allrasd, surface, parameter, parameter_usage, use_bulk_water, Refine_Data, use_lay_el)
Yref = allrasd.RMS
return Xref, Yref
