NumPy : Beginner's Guide - Third Edition

Time for action – drawing a square wave

We will initialize t just as in the previous section. We need to sum a number of terms. The higher the number of terms, the more accurate the result; k = 99 should be sufficient. In order to draw a square wave, follow these steps:

1. We will start by initializing t and k. Set the initial values for the function to 0:

   t = np.linspace(-np.pi, np.pi, 201)
   k = np.arange(1, 99)
   k = 2 * k - 1
   f = np.zeros_like(t)

2. Compute the function values with the sin() and sum() functions:

   for i, ti in enumerate(t):
      f[i] = np.sum(np.sin(k * ti)/k)
   
   f = (4 / np.pi) * f

3. The code to plot is almost identical to the one in the previous section:

   plt.plot(t, f)
   plt.title('Square wave')
   plt.grid()
   plt.show()

   The resulting square wave generated ...