Python group_delay Examples

Example #1

File: plot_2_4_grp_delay_inst_freq_comprison.py Project: dhuadaar/pytftb

sufficiently high.

"""

import numpy as np
import matplotlib.pyplot as plt
from tftb.generators import amgauss, fmlin
from tftb.processing import loctime, locfreq, inst_freq, group_delay

time_instants = np.arange(2, 256)
sig1 = amgauss(256, 128, 90) * fmlin(256)[0]
tm, T1 = loctime(sig1)
fm, B1 = locfreq(sig1)
ifr1 = inst_freq(sig1, time_instants)[0]
f1 = np.linspace(0, 0.5 - 1.0 / 256, 256)
gd1 = group_delay(sig1, f1)

plt.subplot(211)
plt.plot(time_instants, ifr1, '*', label='inst_freq')
plt.plot(gd1, f1, '-', label='group delay')
plt.xlim(0, 256)
plt.grid(True)
plt.legend()
plt.title("Time-Bandwidth product: {0}".format(T1 * B1))
plt.xlabel('Time')
plt.ylabel('Normalized Frequency')


sig2 = amgauss(256, 128, 30) * fmlin(256, 0.2, 0.4)[0]
tm, T2 = loctime(sig2)
fm, B2 = locfreq(sig2)

Example #2

#! /usr/bin/env python
# -*- coding: utf-8 -*-
# vim:fenc=utf-8
#
# Copyright © 2015 jaidev <jaidev@newton>
#
# Distributed under terms of the MIT license.
"""
Example in section 2.4 of the tutorial.
"""

from tftb.generators import fmlin
from tftb.processing import group_delay
import numpy as np
import matplotlib.pyplot as plt

signal, _ = fmlin(256)
fnorm = np.linspace(0, .5, 10)
gd = group_delay(signal, fnorm)
plt.plot(gd, fnorm)
plt.grid(True)
plt.xlim(0, 256)
plt.xlabel('Time')
plt.ylabel('Normalized Frequency')
plt.title('Group Delay Estimation')
plt.show()

Example #3

"""
Example in section 2.4 of the tutorial.
"""

import numpy as np
import matplotlib.pyplot as plt
from tftb.generators import amgauss, fmlin
from tftb.processing import loctime, locfreq, inst_freq, group_delay

time_instants = np.arange(2, 256)
sig1 = amgauss(256, 128, 90) * fmlin(256)[0]
tm, T1 = loctime(sig1)
fm, B1 = locfreq(sig1)
ifr1 = inst_freq(sig1, time_instants)[0]
f1 = np.linspace(0, 0.5 - 1.0 / 256, 256)
gd1 = group_delay(sig1, f1)

plt.subplot(211)
plt.plot(time_instants, ifr1, '*', label='inst_freq')
plt.plot(gd1, f1, '-', label='group delay')
plt.xlim(0, 256)
plt.grid(True)
plt.legend()
plt.title("Time-Bandwidth product: {0}".format(T1 * B1))
plt.xlabel('Time')
plt.ylabel('Normalized Frequency')

sig2 = amgauss(256, 128, 30) * fmlin(256, 0.2, 0.4)[0]
tm, T2 = loctime(sig2)
fm, B2 = locfreq(sig2)
ifr2 = inst_freq(sig2, time_instants)[0]

Example #4

File: plot_2_4_group_delay.py Project: dhuadaar/pytftb

#
# Copyright © 2015 jaidev <jaidev@newton>
#
# Distributed under terms of the MIT license.

"""
=================================
Group Delay Estimation of a Chirp
=================================

Constuct a chirp and estimates its `group delay
<https://en.wikipedia.org/wiki/Group_delay_and_phase_delay>`_.

"""

from tftb.generators import fmlin
from tftb.processing import group_delay
import numpy as np
import matplotlib.pyplot as plt

signal, _ = fmlin(256)
fnorm = np.linspace(0, .5, 10)
gd = group_delay(signal, fnorm)
plt.plot(gd, fnorm)
plt.grid(True)
plt.xlim(0, 256)
plt.xlabel('Time')
plt.ylabel('Normalized Frequency')
plt.title('Group Delay Estimation')
plt.show()

Example #5

File: group_delay.py Project: dafx/pytftb

#! /usr/bin/env python
# -*- coding: utf-8 -*-
# vim:fenc=utf-8
#
# Copyright © 2015 jaidev <jaidev@newton>
#
# Distributed under terms of the MIT license.

"""

"""

import numpy as np
import matplotlib.pyplot as plt
from tftb.generators import amgauss, fmlin
from tftb.processing import group_delay

x = amgauss(128, 64.0, 30) * fmlin(128, 0.1, 0.4)[0]
fnorm = np.arange(0.1, 0.38, step=0.04)
gd = group_delay(x, fnorm)
plt.plot(gd, fnorm)
plt.xlim(0, 128)
plt.grid()
plt.title('Group delay estimation of linear chirp')
plt.xlabel('Group delay')
plt.ylabel('Normalized frequency')
plt.show()

Example #6

#! /usr/bin/env python
# -*- coding: utf-8 -*-
# vim:fenc=utf-8
#
# Copyright © 2015 jaidev <jaidev@newton>
#
# Distributed under terms of the MIT license.
"""

"""

import numpy as np
import matplotlib.pyplot as plt
from tftb.generators import amgauss, fmlin
from tftb.processing import group_delay

x = amgauss(128, 64.0, 30) * fmlin(128, 0.1, 0.4)[0]
fnorm = np.arange(0.1, 0.38, step=0.04)
gd = group_delay(x, fnorm)
plt.plot(gd, fnorm)
plt.xlim(0, 128)
plt.grid()
plt.title('Group delay estimation of linear chirp')
plt.xlabel('Group delay')
plt.ylabel('Normalized frequency')
plt.show()

Example #7

File: 2_7_multicomp_nonstat_instfreq_grpdlay.py Project: dafx/pytftb

#  x=x1+x2;
#  ifr=instfreq(x); subplot(211); plot(ifr);
#  fn=0:0.01:0.5; gd=sgrpdlay(x,fn);
#  subplot(212); plot(gd,fn);
from tftb.generators import fmlin
from tftb.processing import inst_freq, group_delay
import matplotlib.pyplot as plt
import numpy as np

N = 128
x1, _ = fmlin(N, 0, 0.2)
x2, _ = fmlin(N, 0.3, 0.5)
x = x1 + x2
ifr = inst_freq(x)[0]
fn = np.arange(0.51, step=0.01)
gd = group_delay(x, fn)

plt.subplot(211)
plt.plot(ifr)
plt.xlim(1, N)
plt.grid(True)
plt.title('Instantaneous Frequency')
plt.xlabel('Time')
plt.ylabel('Normalized Frequency')

plt.subplot(212)
plt.plot(gd, fn)
plt.xlim(1, N)
plt.grid(True)
plt.title('Group Delay')
plt.xlabel('Time')

Example #8

#  x=x1+x2;
#  ifr=instfreq(x); subplot(211); plot(ifr);
#  fn=0:0.01:0.5; gd=sgrpdlay(x,fn);
#  subplot(212); plot(gd,fn);
from tftb.generators import fmlin
from tftb.processing import inst_freq, group_delay
import matplotlib.pyplot as plt
import numpy as np

N = 128
x1, _ = fmlin(N, 0, 0.2)
x2, _ = fmlin(N, 0.3, 0.5)
x = x1 + x2
ifr = inst_freq(x)[0]
fn = np.arange(0.51, step=0.01)
gd = group_delay(x, fn)

plt.subplot(211)
plt.plot(ifr)
plt.xlim(1, N)
plt.grid(True)
plt.title('Instantaneous Frequency')
plt.xlabel('Time')
plt.ylabel('Normalized Frequency')

plt.subplot(212)
plt.plot(gd, fn)
plt.xlim(1, N)
plt.grid(True)
plt.title('Group Delay')
plt.xlabel('Time')