Python编程：从入门到实践 - matplotlib篇 - Random Flow

随机漫游

# random_flow.py 随机漫游

import random

class RandomFlow():
    """一个生成随机漫游数据的类"""

    def __init__(self, num_points=5000):
        self.num_points = num_points

        self.x_values = [0]
        self.y_values = [0]

    def fill_walk(self):
        while len(self.x_values) < self.num_points:
            # To left or to right
            x_direction = random.choice([1, -1])
            x_distance = random.choice([0, 1, 2, 3, 4])
            x_step = x_direction * x_distance

            y_direction = random.choice([1, -1])
            y_distance = random.choice([0, 1, 2, 3, 4])
            y_step = y_direction * y_distance

            # must move
            if x_step == 0 and y_step == 0:
                continue

            next_x = self.x_values[-1] + x_step
            next_y = self.y_values[-1] + y_step            

            self.x_values.append(next_x)
            self.y_values.append(next_y)

# rf_visual.py 实现随机漫游

import matplotlib.pyplot as plt
import random

from random_flow import RandomFlow

while True:
    rf = RandomFlow()
    rf.fill_walk()

    plt.plot(rf.x_values, rf.y_values, color='b', linewidth=1)

    plt.title('Random Flow', fontsize=24)

    plt.axes().get_xaxis().set_visible(False)
    plt.axes().get_yaxis().set_visible(False)

    filename = 'rf_' + str(random.randint(000000, 999999)) + '.png'
    plt.savefig('images/' + filename, bbox_inches='tight')

    flag = input('Keep flowing? (Y/N): ')
    if flag.lower() not in ['y', 'yes']:
        break