Time for action – plotting the sinc function

We will plot the sinc function. Perform the following steps to do so:

1. Compute evenly spaced values with the NumPy linspace function.

   x = np.linspace(0, 4, 100)

2. Call the NumPy sinc function to compute the function values.

   vals = np.sinc(x)

3. Plot the sinc function with Matplotlib.

   plot(x, vals)
   show()

   The sinc function would have the following output:

   

   The sinc2d function requires a two-dimensional array. We can create it with the outer function resulting in the following plot:

   

What just happened?

We plotted the well-known sinc function with the NumPy sinc function (see plot_sinc.py).

import numpy as np
from matplotlib.pyplot import plot, show

x = np.linspace(0, 4, 100)
vals = np.sinc(x)

plot(x, vals)
show()

We did the same for two dimensions (see sinc2d.py).

import numpy as np
from matplotlib.pyplot import imshow, show

x = np.linspace(0, 4, 100)
xx = np.outer(x, x)
vals = np.sinc(xx)

imshow(vals)
show()