创建Pi的数字直方图

Question

I'm having trouble plotting a histogram of the distribution of the first million digits of Pi.

import numpy as np
import matplotlib as mpl
import matplotlib.pyplot as plt
# import pandas as pd

"""
This program charts a histogram of the distribution of the digits in pi.
"""
# Assign variable to the 1 Million digits of Pi
file_object = open('pi_million_digits.txt', 'r')
pi = file_object.read()

# Add the million digits to a list for plotting.
digit_list = []
for digit in pi:
    digit_list.append(digit)

# Plot the histogram
bins = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

plt.hist(digit_list, bins, histtype = 'bar', rwidth = 0.5)

plt.title('Distribution of Digits in Pi')
plt.xlabel('Digits')
plt.ylabel('Times appeared in the first million digits of Pi')

plt.show()

This code dumps all digits into one bin, and I can't figure out how to assign each digit to its respective bin.

This code also tries to graph the decimal point in Pi but I'm not too concerned about fixing that right now.

Any help on cleaning this up and fixing the graph is appreciated.

Here is a link for the first million digits of pi to save as a .txt doc

Answer 1

Your issue is that as your read your digits from a file, they are all treated as strings. What you need to do is cast each digit to an integer with

digit_list.append(int(digit))

-in order for them to be binned according to your bin you provided.