Generates taxicab vs. euclidean distance graphic

distances.py

#!/usr/bin/env python

import numpy as np
import matplotlib.pyplot as plt

from matplotlib.ticker import MultipleLocator, FormatStrFormatter


def draw_distances(path="atap_ch06_euclidean_manhattan_distance.png"):

    _, ax = plt.subplots(figsize=(6,6))


    points = np.array([
        [2, 2], [8, 8]
    ])

    ax.plot([2, 2, 8], [2, 8, 8], c='r', lw=2, label="$D=12$")
    ax.plot([2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8], [2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8], c='b', lw=2)
    ax.plot(points[:,0], points[:,1], c='g', lw=3, label="$D=\sqrt{72}$")
    ax.plot([2, 7, 7, 8, 8], [2, 2, 4, 4, 8], c='m', lw=2)

    ax.scatter(points[:,0], points[:,1], s=104, c='k', zorder=7)

    majorLocator = MultipleLocator(2)
    majorFormatter = FormatStrFormatter('%d')
    minorLocator = MultipleLocator(1)

    for axis in (ax.xaxis, ax.yaxis):
        axis.set_major_locator(majorLocator)
        axis.set_major_formatter(majorFormatter)
        axis.set_minor_locator(minorLocator)

    ax.set_xlim(0, 10)
    ax.set_ylim(0, 10)
    ax.grid(which="major", lw=1)
    ax.grid(which="minor", lw=0.5)
    ax.set_axisbelow(True)
    ax.legend(loc="lower right", frameon=True)

    plt.savefig(path)




if __name__ == "__main__":
    draw_distances()