The first three functions use fixed column numbers:
1. Phase Structure Function. z = a * x**b * sin(y)**c + d For the task ATMOS. x, y and z are in column 5, 6 and 8 resp.
2. z = a * x**b + c * y x, y, and z in column 5, 4, and 8
3. z = a * x**2 + b * x + c x, z in column 1 and 2 respectively.
The column numbers must be specified for following functions: Lines that begin with '#' are ignored. Giberish can appear in unused columns. Columns are separated by blanks. The maximum line length is 320 characters. Column numbers for x, y, and z specified below.
4. z = a * x**b + c
5. z = a + b * x + c * x**2 + d * x**3
6. Comet model radial profile of surface density (brightness) z = a/x * integral{exp[-x/b sec(theta)]} theta= -pi/2 to pi/2
7. Atmospheric opacity: z = a + b*(1-exp(-c*x)) ! Tb = Trx + Tsky(1-exp(-airmass*tau0))
8. Drift scan analysis z = a * (exp(-b*(x-c)**2) - exp(-b*(x-d)**2))
9. Primary beam pattern polynomial fit. z = 1 + a1*x**2 + a2*x**4 + ... "x" is in units of arcmin*GHz.
10. Primary beam pattern inverse polynomial fit. z = 1/(1 + a1*x**2 + a2*x**4 + ... ) "x" is in units of arcmin*GHz.
11. Primary beam pattern cos**6 fit. z = a1*cos(x)**6 "x" is in units of arcmin*GHz.
12. line length fit: z = a1*cos(2pi*a2*x + a3) "x" is in MHz, a1 is amplitude, a2 is the line length in microsec, and a3 is the phase offset.
An initial guess must be specified for each parameter used. Default=0,0,0,0,0,0 may not be a good starting guess.