Time for action – drawing a square wave

We will initialize t just like in the previous tutorial. 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 initial values for the function to 0:

   t = np.linspace(-np.pi, np.pi, 201)
   k = np.arange(1, float(sys.argv[1]))
   k = 2 * k - 1
   f = np.zeros_like(t)

2. This step should be a straightforward application of the sin and sum functions:

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

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

   plot(t, f)
   show()

   The resulting square wave generated with k = 99 is as follows:

   

What just happened?

We generated a square wave or, at least, a fair approximation of it, using the sin function. The input values were assembled with linspace and the k values with the arange function (see squarewave.py):

import numpy...