How to plot longitudinal magnitude spectrum in Matplotlib using Python?

To plot magintude spectrum, we can take the following steps −

Set the figure size and adjust the padding between and around the subplots.
Get random seed value.
Initialize dt for sampling interval and find the sampling frequency.
Create random data points for t.
To generate noise, get nse, r, cnse and s using numpy
Create a figure and a set of subplots using subplots() method.
Set the title of the plot.
Plot the longitudinal magnitude spectrum.
To display the figure, use show() method.

Example

import matplotlib.pyplot as plt
import numpy as np

plt.rcParams["figure.figsize"] = [7.50, 3.50]
plt.rcParams["figure.autolayout"] = True

np.random.seed(0)

dt = 0.01 # sampling interval
Fs = 1 / dt # sampling frequency
t = np.arange(0, 10, dt)

# generate noise:
nse = np.random.randn(len(t))
r = np.exp(-t / 0.05)
cnse = np.convolve(nse, r) * dt
cnse = cnse[:len(t)]
s = 0.1 * np.sin(4 * np.pi * t) + cnse

fig, axs = plt.subplots()
axs.set_title("Longitudinal Magnitude Spectrum")
axs.magnitude_spectrum(s, Fs=Fs, scale='dB', color='C1')
plt.show()

Output

Rishikesh Kumar Rishi

Updated on: 2021-06-16T12:10:06+05:30

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