кусочно линейная интерполяция

from matplotlib import pyplot as plt
from matplotlib import pylab
import metodslau_kramer
# def kusochnolineynay(arr):
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]]
n = 10000
arrnew = []

for i in range(0,len(arr)-1):
    koef = metodslau_kramer.kramermethod(2,[[1,arr[i][0]],[1,arr[i+1][0]]],[arr[i][1],arr[i+1][1]])
    h = (i + 1 - i) / n
    for k in range(n):
        znacheniye = koef[0]+koef[1] * (arr[i][0] + k * h)
        arrnew.append([arr[i][0] + k * h,znacheniye])
plt.plot([x[0] for x in arrnew], [y[1] for y in arrnew])
plt.show()