Frequency swept signals

This page demonstrates two functions in scipy.signal for generating frequency-swept signals: chirp and sweep_poly.

Some of these require SciPy 0.8.

To run the code samples, you will need the following imports:

import numpy as np
from scipy.signal import chirp, sweep_poly

Linear Chirp

Sample code:

t = np.linspace(0, 10, 5001)
w = chirp(t, f0=12.5, f1=2.5, t1=10, method='linear')

Quadratic Chirp

Sample code:

t = np.linspace(0, 10, 5001)
w = chirp(t, f0=12.5, f1=2.5, t1=10, method='quadratic')

Sample code using vertex_zero:

t = np.linspace(0, 10, 5001)
w = chirp(t, f0=12.5, f1=2.5, t1=10, method='quadratic', vertex_zero=False)

Logarithmic Chirp

Sample code:

t = np.linspace(0, 10, 5001)
w = chirp(t, f0=12.5, f1=2.5, t1=10, method='logarithmic')

Hyperbolic Chirp

Sample code:

t = np.linspace(0, 10, 5001)
w = chirp(t, f0=12.5, f1=2.5, t1=10, method='hyperbolic')

Sweep Poly

Sample code:

p = np.poly1d([0.05, -0.75, 2.5, 5.0])
t = np.linspace(0, 10, 5001)
w = sweep_poly(t, p)

The script that generated the plots is here

Attachments

• chirp_hyperbolic.png
• chirp_linear.png
• chirp_logarithmic.png
• chirp_plot.py
• chirp_quadratic.png
• chirp_quadratic_v0false.png
• sweep_poly.png