shifting-exp.py

""" Shifting Exponential Polynomials

Script generating plots describing the movement of samples for a path in the space of complex exponential polynomial
(periodic bandlimited function), not included in the paper.

To use just run

    python shifting-exp.py

script does not take any command line arguments or flags.
"""

from matplotlib import pylab
from pylab import rcParams
from signals import *

rcParams['figure.figsize'] = 5, 4

signal = SignalExp([0, 1, 0])

change = np.array([0, 1, 0])
alpha = np.linspace(0, 5)
t = np.linspace(0, 2 * np.pi)
sample_pos = np.multiply([0.3, 0.5, 0.7, 0.9, 1.1, 1.3, 1.5, 1.7], np.pi)

pylab.ion()
pylab.plot(t, signal.get_samples(t), 'k', lw=2)
sample_val = signal.get_samples(sample_pos)
pylab.stem(sample_pos, sample_val, 'b')
pylab.ioff()
pylab.show()

pylab.ion()
for s in sample_pos:
    p = signal.path(s, 0.1 * change)
    pylab.plot(p, alpha, lw=3)
pylab.ylabel(r'$\alpha$', fontsize=30)
pylab.xlim([0, 2 * np.pi])
pylab.ioff()
pylab.show()

pylab.ion()
p1 = signal.path(sample_pos[0], 0.1 * change)
for s in sample_pos:
    p = signal.path(s, 0.1 * change)
    pylab.plot(p1, p, lw=3)
pylab.ioff()
pylab.show()