- Square waves are period waveforms.
- However, Square waves are non-sinusoidal. The transition between the peak values is instantaneous in a square wave.
- The period of the square wave that is starting from a position like zero crossing the time it takes to return to the same position again.
- The period of the square wave is also called the pulse width.
- To draw a square wave using matplotlib, scipy and numpy following details are required
- Frequency of the square wave - Say 10 Hz - That is 10 cycles per second
- The sampling frequency - That is how many data points with which the square wave is being constructed - higher the data points smoother the square is.
- Square waves have a duty cycle of 50%. That is, the percentage of the waveform that occurs above zero axes is 50% for a square wave.
- By default the signal.square() function of scipy takes a duty value of 0.5.
from scipy import signal
import matplotlib.pyplot as plot
import numpy as np
# Sampling rate 1000 hz / second
t = np.linspace(0, 1, 1000, endpoint=True)
# Plot the square wave signal
plot.plot(t, signal.square(2 * np.pi * 5 * t))
# Give a title for the square wave plot
plot.title('Sqaure wave - 5 Hz sampled at 1000 Hz /second')
# Give x axis label for the square wave plot
# Give y axis label for the square wave plot
# Provide x axis and line color
# Set the max and min values for y axis
# Display the square wave drawn