Kalman-and-Bayesian-Filters.../code/particle_filter.py
2015-08-01 08:52:48 -07:00

88 lines
1.9 KiB
Python

# -*- coding: utf-8 -*-
"""Copyright 2015 Roger R Labbe Jr.
Code supporting the book
Kalman and Bayesian Filters in Python
https://github.com/rlabbe/Kalman-and-Bayesian-Filters-in-Python
This is licensed under an MIT license. See the LICENSE.txt file
for more information.
"""
from __future__ import (absolute_import, division, print_function,
unicode_literals)
import math
import matplotlib.pyplot as plt
import numpy as np
from numpy.random import uniform
from numpy.random import randn
import scipy.stats
import random
if __name__ == '__main__':
N = 2000
pf = ParticleFilter(N, 100, 100)
#pf.particles[:,2] = np.random.randn(pf.N)*np.radians(10) + np.radians(45)
z = np.array([20, 20])
#pf.create_particles(mean=z, variance=40)
mu0 = np.array([0., 0.])
plt.plot(pf, weights=False)
fig = plt.gcf()
#fig.show()
#fig.canvas.draw()
#plt.ioff()
for x in range(10):
z[0] = x+1 + randn()*0.3
z[1] = x+1 + randn()*0.3
pf.predict((1,1), (0.2, 0.2))
pf.weight(z=z, var=.8)
neff = pf.neff()
print('neff', neff)
if neff < N/2 or N <= 2000:
pf.resample()
mu, var = pf.estimate()
if x == 0:
mu0 = mu
#print(mu - z)
#print(var)
plot(pf, weights=True)
#plt.plot(z[0], z[1], marker='v', c='r', ms=10)
plt.plot(x+1, x+1, marker='*', c='r', ms=10)
plt.scatter(mu[0], mu[1], c='g', s=100)#,
#s=min(500, abs((1./np.sum(var)))*20), alpha=0.5)
plt.plot([0,100], [0,100])
plt.tight_layout()
plt.pause(.002)
#fig.canvas.draw()
#pf.assign_speed_by_gaussian(1, 1.5)
#pf.move(h=[1,1], v=1.4, t=1)
#pf.control(mu-mu0)
mu0 = mu
plt.ion()