sd.fitter - Tool

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5.1.4 sd.fitter - Tool

General fitting tool
Description

The fitter is an object to fit data. This contains both baseline fitting and spectral line fitting. For baseline fitting, simple polynomial fitting with arbitrary order is available. For spectral line fitting, Gaussian and Lorentzian fitting are supported. It allows fitting of multiple lines, but it doesn’t support hyperfine fitting, i.e. multiple line fitting under some constraints.

The constructor doesn’t take any arguments. It just creates a fitter object that no state is set.

Example

        s = sd.scantable(’myscan.asap’)
        s.set_cursor(thepol=1)        # select second pol
        f = sd.fitter()               # create fitter object
        f.set_scan(s)
        f.set_function(poly=0)
        f.fit(row=0)                  # fit first row

Methods

auto_fit	Return a scan where the function is applied to all rows
commit	Return a new scan where the fits have been subtracted
fit	Execute actual fitting process
get_area	Return the area under the fitted gaussian/lorentzian component
get_chi2	Return χ² value
get_errors	Return the errors in parameters
get_estimate	Return the parameter estimates
get_fit	Return the fitted ordinate values
get_parameters	Return the fit parameters
get_residual	Return the residual of the fit
plot	Plot fit
set_data	Set the abcissa and ordinate for the fit
set_function	Set the function to be fitted
set_gauss_parameters	Set the parameters of Gaussian component
set_lorentz_parameters	Set the parameters of Lorentzian component
set_parameters	Set the parameters to be fitted
set_scan	Set the data as a scantable
set_sinusoid_parameters	Set the parameters of Sinusoidal component
store_fit	Save fit parameters

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