x	= wavelength in Angstroms
ratio	= the factor by which the existing efficiences should be multiplied

2	ratio= -0.42*atan(0.0022*(x**3.0-8.7**3.0)) + 1.26

3	no change

4	ratio= -0.60*atan(0.00150*((x+1.2)**3.0-9.0**3.0))
		+0.59*atan(0.00022*((x+1.2)**4.0-5.5**4.0))  +0.88

5	ratio= 0.16*atan(0.0022*((x+1)**3.0-3.0**3.0)) + 0.97

6	ratio= -0.59*atan(0.00160*((x+1.2)**3.0-9.0**3.0))
		+0.59*atan(0.00022*((x+1.2)**4.0-5.5**4.0))  +0.88

7	ratio= 65.0 * 2.718**(-8.0/(x-1.1)) /((x-0.4)**2.4) +0.97