《Python编程:从入门到实践》---项目2
第15章 生成数据
15-1 立方：
import matplotlib.pyplot as plt
'''
x_values = [1, 2, 3, 4, 5]
y_values = [x**3 for x in x_values]
plt.scatter(x_values,y_values,s=100)
#plt.plot(x_values,y_values, linewidth=5)# 设置图表标题，并给坐标轴加上标签
plt.title("Cubic Numbers", fontsize=24)
plt.xlabel("Value", fontsize=14)
plt.ylabel("Cubic of Value", fontsize=14)# 设置刻度标记的大小
plt.tick_params(axis='both', which='major',labelsize=14)
plt.show()
'''
x_values = list(range(1,5001))
y_values = [x**3 for x in x_values]
plt.scatter(x_values,y_values,s=100)
#plt.plot(x_values,y_values, linewidth=5)# 设置图表标题，并给坐标轴加上标签
plt.title("Cubic Numbers", fontsize=24)
plt.xlabel("Value", fontsize=14)
plt.ylabel("Cubic of Value", fontsize=14)# 设置刻度标记的大小
plt.tick_params(axis='both', which='major',labelsize=14)
plt.show()15-2 彩色立方
plt.scatter(x_values,y_values,c='red',cmap=plt.cm.Blues,
edgecolor='none',s=10)15-3 分子运动 + 15-4 改进的随机漫步
random_walk.py
from random import choice
class RandomWalk():
def __init__(self, num_points=500):
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, 4,5,6,7,8])
x_step = x_direction * x_distance
y_direction = choice([1, -1])
y_distance = choice([0, 1, 2, 3, 4,5,6,7,8])
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
rw = RandomWalk()
rw.fill_walk()
#plt.scatter(rw.x_values, rw.y_values, s=15)
plt.plot(rw.x_values, rw.y_values, linewidth=1)
plt.show()（1），将x,y的方向删除 （只保留1，或 -1）
（2,），原始状态
15-5 重构
random_walk.py
关于类的函数，还要复习
from random import choice
class RandomWalk():
def __init__(self, num_points=500):
self.num_points = num_points
self.x_values = [0]
self.y_values = [0]
def get_step(self):
direction = choice([1,-1])
distance = choice([0, 1, 2, 3, 4,5,6,7,8])
step = direction * distance
return step
def fill_walk(self):
while len(self.x_values) < self.num_points:
x_step=self.get_step()#调用类中的函数，要用self.+函数名的形式
y_step=self.get_step()
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)
die.py:
from random import randint
class Die():
"""表示一个骰子的类"""
def __init__(self, num_sides=6):
"""骰子默认为6面"""
self.num_sides = num_sides
def roll(self):
""""返回一个位于1和骰子面数之间的随机值"""
return randint(1, self.num_sides)
15-6 自动生成标签:
from die import Die
import pygal
# 创建一个D6
die_1 = Die()
die_2 = Die(10)
# 掷几次骰子，并将结果存储在一个列表中
results = []
for roll_num in range(100):
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)
# 对结果进行可视化
hist = pygal.Bar()
hist.title = "Results of rolling one D6 1000 times."
#答案
x_values=list(range(1,20))
hist.x_labels = [x for x in x_values]
hist.x_title = "Result"
hist.y_title = "Frequency of Result"
hist.add('D6', frequencies)
hist.render_to_file('dice_visual.svg')
15-7 两个D8骰子:
以10的次方为量级:
掷骰子次数最大可达：100000次
15-8 同时掷三个骰子：
from die import Die
import pygal
# 创建一个D6
die_1 = Die(8)
die_2 = Die(8)
die_3 = Die(8)
# 掷几次骰子，并将结果存储在一个列表中
results = []
for roll_num in range(1000):
result = die_1.roll()+die_2.roll()+die_3.roll()
results.append(result)
frequencies=[]
max_result=die_1.num_sides+die_2.num_sides+die_3.num_sides
for value in range(2, max_result+1):
frequency = results.count(value)
frequencies.append(frequency)
# 对结果进行可视化
hist = pygal.Bar()
hist.title = "Results of rolling one D6 1000 times."
x_values=list(range(3,25))
hist.x_labels = [x for x in x_values]
hist.x_title = "Result"
hist.y_title = "Frequency of Result"
hist.add('D6', frequencies)
hist.render_to_file('dice_visual.svg')
15-9 略
15-10 练习使用本章介绍的两个库