Попытка реализации кусочно квадратичной интерполяции

import metodslau_kramer
from matplotlib import pyplot as plt
from matplotlib import pylab

n = 1000
arr = [[1, 1], [2, 0], [3, 3], [4, 10], [5, 5], [6, 1],[7,1],[8,-1],[9,12],[10,11],[11,0],[12,10]]
arrnew = []
for i in range(0, len(arr)-2):
    print(i)
    koef = metodslau_kramer.kramermethod(3, [[1, arr[i][0], arr[i][0] ** 2], [1, arr[i + 1][0], arr[i + 1][0] ** 2],
                                             [1, arr[i + 2][0], arr[i + 2][0] ** 2]],
                                         [arr[i][1], arr[i + 1][1], arr[i + 2][1]])
    h = (i + 1 - i) / n
    for k in range(n + 1):
        znach = koef[0] + koef[1] * (arr[i][0] + k * h) + koef[2] * ((arr[i][0] + k * h) ** 2)
        arrnew.append([i + k * h, znach])

x1 = [x[0] for x in arrnew]
y1 = [x[1] for x in arrnew]
plt.plot(x1, y1)
plt.show()