docs: def PROFILE_DOPPLER(sg0,GamD,sg):
      """
      # Doppler profile.
      # Input parameters:
      #   sg0: Unperturbed line position in cm-1 (Input).
      #   GamD: Doppler HWHM in cm-1 (Input)
      #   sg: Current WaveNumber of the Computation in cm-1 (Input).
      """
      return cSqrtLn2divSqrtPi*exp(-cLn2*((sg-sg0)/GamD)**2)/GamD