Kalman-and-Bayesian-Filters.../experiments/taylor.py

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# -*- coding: utf-8 -*-
"""
Created on Thu Mar 19 08:26:08 2015
@author: rlabbe
"""
import numpy as np
import matplotlib.pyplot as plt
from math import sin, cos, factorial
def df(x, p):
if p == 0:
return sin(x)
return x
if p % 4 == 1:
return cos(x)
if p % 4 == 2:
return -sin(x)
if p % 4 == 3:
return -cos(x)
return sin(x)
def taylor(df, x, a, n):
f = 0.0
for i in range(n+1):
term = df(a, i) * (x - a)**i / factorial(i)
f += term
return f
x = 0.1
a = 0.8
n = 1
plt.cla()
xs = np.linspace(-2, 2, 100)
ts = [taylor(df, i, a, n) for i in xs]
plt.plot(xs, np.sin(xs))
plt.plot(xs, ts)