NRAO Home > CASA > CASA Toolkit Reference Manual
##### sd.fitter.set_function - Function

5.1.4 Set the function to be fitted
Description

Set the function to be fit.

The argument to be set determines what the fitter will do. If you want to do polynomial fitting, you have to set poly or lpoly arguments. The value of poly or lpoly are interpreted as an order of the polynomial function to be used for fitting. The poly is for non-linear least squares fitting, while lpoly is for linear one. If you want to do line fitting, you have to set either gauss or lorentz arguments. In that case, values of gauss or lorentz arguments are interpreted as a number of gaussian/lorentzian components. Apparently, gauss=0 or lorentz=0 causes an exception.

Note that all the above arguments are exclusive each other.

Arguments

 Inputs poly Use a polynomial of the order given with nonlinear least squares fit allowed: integer Default: lpoly Use a polynomial of the order given with linear least squares fit allowed: integer Default: gauss Fit the number of gaussian specified allowed: integer Default: lorentz Fit the number of lorentzian specified allowed: integer Default:
Returns

Example

f=sd.fitter()
# will fit a 3rd order polynomial via nonlinear method
f.set_function(poly=3)
# will fit a 3rd order polynomial via linear method
f.set_function(lpoly=3)
# will fit two gaussians
f.set_function(gauss=2)
# will fit two lorentzians
f.set_function(lorentz=2)