1、绘制折线图
import matplotlib.pyplot as plt
import numpy as np
input_values = [1, 2, 3, 4, 5]
squares = [1, 4, 9, 16, 25]
plt.plot(input_values, squares, linewidth=5)
plt.title("Square numbers", fontsize=24)
plt.xlabel("Value", fontsize=14)
plt.ylabel("Square of Value", fontsize=14)
plt.tick_params(axis='both', labelsize=14)
plt.show()
2、绘制折线图
使用实参s 设置了绘制图形时使用的点的尺寸；
要删除数据点的轮廓，可在调用scatter() 时传递实参edgecolor='none'；
颜色映射 （colormap）是一系列颜色，它们从起始颜色渐变到结束颜色；
将参数c 设置成了一个 y 值列表，并使用参数cmap 告诉pyplot 使用哪个颜色映射；
import matplotlib.pyplot as plt
x_values = list(range(1, 1001))
y_values = [x ** 2 for x in x_values]
plt.scatter(x_values, y_values, c=y_values, cmap=plt.cm.Blues, edgecolor='none', s=40)
plt.title("Square Numbers", fontsize=24)
plt.xlabel("Value", fontsize=14)
plt.ylabel("Square of Value", fontsize=14)
plt.tick_params(axis='both', which='major', labelsize=14)
plt.axis([0, 1100, 0, 1100000])
plt.show()
plt.savefig('squares_plot.png', bbox_inches='tight')
3、随机漫步
RandomWalk 的类，它随机地选择前进方向；
为做出随机决策，我们将所有可能的选择都存储在一个列表中，并在每次做决策时都使用choice() 来决定使用哪种选择；
fill_walk() 来生成漫步包含的点；
random_walk.py
from random import choice
class RandomWalk():
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:
x_direction = choice([1, -1])
x_distance = choice([0, 1, 2, 3, 4])
x_step = x_direction * x_distance
y_direction = choice([1, -1])
y_distance = choice([0, 1, 2, 3, 4])
y_step = y_direction * y_distance
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)
rw_visual.py
import matplotlib.pyplot as plt
from random_walk import RandomWalk
while True:
rw = RandomWalk()
rw.fill_walk()
plt.figure(dpi=128, figsize=(10, 6))
point_numbers = list(range(rw.num_points))
plt.scatter(rw.x_values, rw.y_values, c=point_numbers, cmap=plt.cm.Blues, edgecolor='none', s=15)
plt.scatter(0, 0, c='green', edgecolors='none', s=100)
plt.scatter(rw.x_values[-1], rw.y_values[-1], c='red', edgecolors='none', s=100)
plt.show()
keep_running = input("Make another walk? (y/n): ")
if keep_running == 'n':
break
4、使用Pygal模拟掷子
创建Die.py
from random import randint
class Die():
def __init__(self, num_sides=6):
self.num_sides = num_sides
def roll(self):
return randint(1, self.num_sides)
掷骰子：绘制直方图，结果保存在die_visual.svg，用浏览器打开
results.count(value)计算列表中为value的个数
from die import Die
import pygal
die = Die()
results = []
for roll_num in range(1000):
result = die.roll()
results.append(result)
frequencies = []
for value in range(1, die.num_sides + 1):
frequency = results.count(value)
frequencies.append(frequency)
print(frequencies)
hist = pygal.Bar()
hist.title = "Results of rolling one D6 1000 times"
hist.x_labels = ['1', '2', '3', '4', '5', '6']
hist.x_title = "Result"
hist.y_title = "Frequency of Result"
hist.add('D6', frequencies)
hist.render_to_file('die_visual.svg')
同时掷两个骰子：
from die import Die
import pygal
die_1 = Die()
die_2 = Die(10)
results = []
for roll_num in range(50000):
result = die_1.roll() + die_2.roll()
results.append(result)
frequencies = []
max_result = die_1.num_sides + die_2.num_sides
for value in range(2, max_result + 1):
frequency = results.count(value)
frequencies.append(frequency)
hist = pygal.Bar()
hist.title = "Results of rolling a D6 and a D10 50,000 times."
hist.x_labels = ['2', '3', '4', '5', '6', '7', '8', '9', '10', '11', '12', '13', '14', '15', '16']
hist.x_title = "Result"
hist.y_title = "Frequency of Result"
hist.add('D6 + D10', frequencies)
hist.render_to_file('different_dice.svg')
结果：
