Poly Fit Class

This module contains functions to fit the potential energy and dipole moment to a polynomial.

Notes:

These functions are used to fit the potential energy and dipole moment to a polynomial. The potential energy is fit to a polynomial of the form: V = a + 0.5*c*dx^2 + d*dx**3 + e*dx**4 + …

Where dx = x - b.

The dipole moment is fit to a polynomial of the form: mu = a + b*x + c* x^2 + …

Where x is the bond distance.

Examples:

>>> from empmap.poly_fit import poly_fit_selector
>>> poly_fit_selector(2)
<function poly_fit_selector.<locals>.fitfunc at 0x7f9e8e9b7f28>

>>> from empmap.poly_fit import mu_fit_selector
>>> mu_fit_selector(2)
<function mu_fit_selector.<locals>.mfunc at 0x7f9e8e9b7f28>

empmap.poly_fit.mu_fit_selector(order)

Returns a list of fitting functions for the given order.

Notes:

These fitting functions are used to fit the dipole moment to a polynomial.

They are of the form: mu = a + b*x + c* x^2 + …

Parameters:

order: int

The order of the fitting function. Available options are 1, 2, 3, 4, 5, 6, 7.

Returns:

mfunc: function

The fitting function. Parameters are in order (x, a, b, c, d, e, f, g)

Raises:

ValueError: If the order is not an integer.

empmap.poly_fit.poly_fit_selector(order)

Returns a list of fitting functions for the given order.

Notes:

These fitting functions are used to fit the potential energy to a polynomial.

They are of the form: V = a + 0.5*c*dx^2 + d*dx**3 + e*dx**4 + …

Where dx = x - b.

Special Case: If the order is 1, the fitting function is linear: V = a + b*x

Parameters:

order: int

The order of the fitting function.

Returns:

fitfunc: function

The fitting function. Parameters are in order (x, a b, c, d, e, …)

Raises:

ValueError: If the order is not an integer.