Kalman-and-Bayesian-Filters.../ukf_internal.py

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# -*- coding: utf-8 -*-
"""
Created on Tue May 27 21:21:19 2014
@author: rlabbe
"""
import matplotlib.pyplot as plt
from matplotlib.patches import Ellipse,Arrow
import stats
import numpy as np
def arrow(x1,y1,x2,y2):
return Arrow(x1,y1, x2-x1, y2-y1, lw=2, width=0.1, ec='k', color='k')
def show_2d_transform():
ax=plt.gca()
ax.add_artist(Ellipse(xy=(2,5), width=2, height=3,angle=70,linewidth=1,ec='k'))
ax.add_artist(Ellipse(xy=(7,5), width=2.2, alpha=0.3, height=3.8,angle=150,linewidth=1,ec='k'))
ax.add_artist(arrow(2, 5, 6, 4.8))
ax.add_artist(arrow(1.5, 5.5, 7, 3.8))
ax.add_artist(arrow(2.3, 4.1, 8, 6))
ax.axes.get_xaxis().set_visible(False)
ax.axes.get_yaxis().set_visible(False)
plt.axis('equal')
plt.xlim(0,10); plt.ylim(0,10)
plt.show()
def show_3_sigma_points():
xs = np.arange(-4, 4, 0.1)
var = 1.5
ys = [stats.gaussian(x, 0, var) for x in xs]
samples = [0, 1.2, -1.2]
for x in samples:
plt.scatter ([x], [stats.gaussian(x, 0, var)], s=80)
plt.plot(xs, ys)
plt.show()
def show_sigma_selections():
ax=plt.gca()
ax.add_artist(Ellipse(xy=(2,5), alpha=0.5, width=2, height=3,angle=0,linewidth=1,ec='k'))
ax.add_artist(Ellipse(xy=(5,5), alpha=0.5, width=2, height=3,angle=0,linewidth=1,ec='k'))
ax.add_artist(Ellipse(xy=(8,5), alpha=0.5, width=2, height=3,angle=0,linewidth=1,ec='k'))
ax.axes.get_xaxis().set_visible(False)
ax.axes.get_yaxis().set_visible(False)
plt.scatter([1.5,2,2.5],[5,5,5],c='k', s=50)
plt.scatter([2,2],[4.5, 5.5],c='k', s=50)
plt.scatter([4.8,5,5.2],[5,5,5],c='k', s=50)
plt.scatter([5,5],[4.8, 5.2],c='k', s=50)
plt.scatter([7.2,8,8.8],[5,5,5],c='k', s=50)
plt.scatter([8,8],[4,6],c='k' ,s=50)
plt.axis('equal')
plt.xlim(0,10); plt.ylim(0,10)
plt.show()
if __name__ == '__main__':
show_sigma_selections()