"""
ECE 09351 - Digital Signal Processing
Lab 1 Question 4

Translated from MATLAB by Aidan Sharpe
Last Modified: January 18, 2025
"""


import numpy as np
import matplotlib.pyplot as plt


def main():
    f_s = 4                     # Sample frequency 4[Hz]
    T_s = 1/f_s                 # Period is reciprocal of frequency

    n = np.arange(100)          # Sample indicies (0 to 99)
    t = n*T_s                   # Conversion between index and time

    x = np.cos(2*np.pi*t/5) + np.sin(4*np.pi*t/7) + np.cos(16*np.pi*t/9)

    plt.stem(n, x)              # Plot samples against index on stem plot
    plt.xlabel("n")
    plt.ylabel("x(n)")
    plt.show()                  # Show the plot


if __name__ == "__main__":
    main()