N-1多项式拟合使用numpy

Question

做一个问题和一个部分涉及使用numpy将一组PES数据拟合到E(R) = summation(Ck*(r - rg))的N-1多项式，其中rg是对PES最小点的猜测。我从导入的PES中获取了所有数据，只需要弄清楚如何将其拟合到多项式

import numpy as np

with open("hf_ccsdt_cbs45.txt", "r") as File:
    inputData = File.read()

    lines = inputData.splitlines()

    captions = lines[0]

    distances = []
    energies = []

    for line in lines[1:]:

        if line.strip() == "": 
            continue

        parts = line.split()
        distances.append(float(parts[0]))
        energies.append(float(parts[1]))

import pylab as pl

pl.plot(distances, energies)
pl.xlabel('Interatmoic Distance R (Bohr)')
pl.ylabel('Energy E[R]/(HARTREE')
pl.show()

r_guess = distances[np.argmin(energies)]