#!/usr/bin/python

# 4.3

import pylab as pl

z = pl.array([[0],[5./12]])

p = pl.array([[1./2],[1./3]])

def zplane(z, p):

    pl.figure(figsize=(8,8))

    x = pl.linspace(-1.5, 1.5)

    pl.plot(pl.zeros_like(x), x, 'b.', x, pl.zeros_like(x), 'b.', markersize=2)

    x = pl.linspace(0, 2*pl.pi, 100)

    pl.plot(pl.cos(x), pl.sin(x), 'b.', markersize=2)

    pl.plot(z, pl.zeros_like(z), 'ro', p, pl.zeros_like(p), 'rx', markersize=8)

    pl.xlabel('Real part')

    pl.ylabel('Imaginary part')

zplane(z, p)

pl.show()