"""This module contains a code example related to
Think Python, 2nd Edition
by Allen Downey
http://thinkpython2.com
Copyright 2015 Allen Downey
License: http://creativecommons.org/licenses/by/4.0/
"""
from __future__ import print_function, division
import sys
import matplotlib.pyplot as plt
from analyze_book1 import process_file
def rank_freq(hist):
"""Returns a list of (rank, freq) tuples.
hist: map from word to frequency
returns: list of (rank, freq) tuples
"""
# sort the list of frequencies in decreasing order
freqs = list(hist.values())
freqs.sort(reverse=True)
# enumerate the ranks and frequencies
rf = [(r+1, f) for r, f in enumerate(freqs)]
return rf
def print_ranks(hist):
"""Prints the rank vs. frequency data.
hist: map from word to frequency
"""
for r, f in rank_freq(hist):
print(r, f)
def plot_ranks(hist, scale='log'):
"""Plots frequency vs. rank.
hist: map from word to frequency
scale: string 'linear' or 'log'
"""
t = rank_freq(hist)
rs, fs = zip(*t)
plt.clf()
plt.xscale(scale)
plt.yscale(scale)
plt.title('Zipf plot')
plt.xlabel('rank')
plt.ylabel('frequency')
plt.plot(rs, fs, 'r-', linewidth=3)
plt.show()
def main(script, filename='emma.txt', flag='plot'):
hist = process_file(filename, skip_header=True)
# either print the results or plot them
if flag == 'print':
print_ranks(hist)
elif flag == 'plot':
plot_ranks(hist)
else:
print('Usage: zipf.py filename [print|plot]')
if __name__ == '__main__':
main(*sys.argv)