# Fit Functions¶

The following fit functions are implemented and can be used within PIGOR or the Measurement class. They can be found in `fit_functions.py`.

`fit_functions.``gauss`(x, a, x0, sigma, export=False)

Gaussian function, used for fitting data.

Parameters: x – parameter a – amplitude x0 – maximum sigma – width export – enable text output of function
`fit_functions.``poly`(x, *args, export=False)

Polynom nth degree for fitting.

Parameters: x (int, float) – parameter *args – list of coefficients [a_N,a_N-1, …, a_1, a_0] export (bool or string, optional) – enable text output of function, defaults to False returns the polynomial str, int, float
```>>> poly(3.4543, 5,4,3,2,1, export='Mathematica')
'5*3.4543^5 + 4*3.4543^4 + 3*3.4543^3 + 2*3.4543^2 + 1*3.4543^1'
```
```>>> poly(3.4543, 5,4,3,2,1)
920.4602110784704
```
`fit_functions.``poly5`(x, a5, a4, a3, a2, a1, a0, export=False)

Polynom 5th degree for fitting.

Parameters: x – parameter a5 – coeff a4 – coeff a3 – coeff a2 – coeff a1 – coeff a0 – coeff export – enable text output of function function – polynomial 5th degree
`fit_functions.``register_fit_function`(func, bounds=(-inf, inf))

This decorator registers a new fit function and writes an entry to fit_function_list.

`fit_functions.``sine`(x, a, omega, phase, c, export=False)

Sine function for fitting data.

Parameters: x – parameter a – amplitude omega – frequency phase – phase c – offset export – enable text output of function
`fit_functions.``sine_lin`(x, a, omega, phase, c, b, export=False)

Sine function with linear term added for fitting data.

Parameters: x – parameter a – amplitude omega – frequency phase – phase c – offset b – slope export – enable text output of function