Plotting Cosine Waves Using Python Matplotlib And Numpy


  • Cosine waves are periodic waves generated out of oscillations.


  • Cosine waves are similar to sine wave however the cosine wave leads sine wave by 90 degrees of phase angle.


  • The cosine curve does not go through the origin.


  • The cosine wave has the same frequency as its corresponding sine wave.


  • The ocean tides are an example of cosine waves.


  • A cosine curve can be plotted by calling the cosine() on a numpy array and using the plot() function of the pyplot module of matplotlib.



import numpy as np

import matplotlib.pyplot as plot


# Get x values of the cosine wave

time        = np.arange(0, 20, 0.2);


# Amplitude of the cosine wave is cosine of a variable like time

amplitude   = np.cos(time)


# Plot a cosine wave using time and amplitude obtained for the cosine wave

plot.plot(time, amplitude)


# Give a title for the cosine wave plot

plot.title('Cosine wave')


# Give x axis label for the cosine wave plot



# Give y axis label for the cosine wave plot

plot.ylabel('Amplitude = cosine(time)')


# Draw the grid for the graph

plot.grid(True, which='both')


plot.axhline(y=0, color='b')


# Display the cosine wave plot



cosine wave

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