什么是Q-Q图,python画Q-Q图代码
时间: 2024-06-10 12:05:23 浏览: 86
Q-Q图是Quantile-Quantile图的简称,用于比较两个数据分布是否相似。其基本思路是将待比较分布中的分位数值按大小顺序排序,计算它们的累积分布函数,然后与一个已知分布(通常是正态分布)做比较,把两个分布函数上对应的点画在一张图上。如果它们重合,则两个分布相同;否则,它们可能不同。
以下是用Python绘制Q-Q图的示例代码:
```python
import numpy as np
import statsmodels.api as sm
import matplotlib.pyplot as plt
# 生成样本数据
np.random.seed(101)
sample = np.random.normal(loc=0, scale=1, size=100)
# 用statsmodels库计算样本分布的QQ图
sm.qqplot(sample, line='s')
# 绘制图表
plt.title("Q-Q plot")
plt.xlabel("Theoretical quantiles")
plt.ylabel("Sample quantiles")
plt.show()
```
这段代码首先使用 NumPy 生成一个100个正态分布的样本数据,然后使用 statsmodels 库的 qqplot 函数绘制 Q-Q 图。line='s' 选项表示在图表中绘制一条45度的对角线,以便比较两个分布之间的差异。最后调用 Matplotlib 的 plot 函数显示图表。
相关问题
pso-Q-learning多分类python代码
下面是一个简单的PSO-Q-learning多分类的Python代码示例,仅供参考:
```python
import numpy as np
import random
# 定义状态和动作
states = np.random.rand(100, 10)
actions = np.arange(5)
# 初始化Q值函数和粒子群
Q = np.zeros((100, 5))
particles = np.random.rand(10, 5, 15)
# 定义PSO参数
w = 0.8
c1 = 0.2
c2 = 0.6
# 定义Q-learning参数
alpha = 0.5
gamma = 0.9
# 计算粒子适应度
def fitness(particle):
scores = []
for i in range(10):
for j in range(5):
state = states[i]
action = actions[j]
next_state = states[np.random.choice(100)]
reward = np.dot(state, particle[j*3:j*3+3])
next_action = np.argmax(Q[next_state])
Q[state, action] = (1-alpha)*Q[state, action] + alpha*(reward+gamma*Q[next_state, next_action])
scores.append(np.mean(np.argmax(Q, axis=1) == i))
return np.mean(scores)
# 更新粒子速度和位置
for i in range(100):
for j in range(5):
particle = particles[i,j]
velocity = particles[i,j,5:10]
pbest_particle = particles[i,j,10:]
gbest_particle = particles[i,j+1,10:]
fitness_p = fitness(particle)
fitness_pbest = fitness(pbest_particle)
fitness_gbest = fitness(gbest_particle)
velocity = w*velocity + c1*random.random()*(pbest_particle-particle) + c2*random.random()*(gbest_particle-particle)
particle = particle + velocity
particles[i,j] = particle
if fitness(particle) > fitness_pbest:
particles[i,j,10:] = particle
if fitness(particle) > fitness_gbest:
particles[i,j+1,10:] = particle
# 更新Q值函数
for i in range(100):
for j in range(5):
state = states[i]
action = actions[j]
next_state = states[np.random.choice(100)]
reward = np.dot(state, particles[i,j*3:j*3+3])
next_action = np.argmax(Q[next_state])
Q[state, action] = (1-alpha)*Q[state, action] + alpha*(reward+gamma*Q[next_state, next_action])
```
需要注意的是,上述代码仅作为一个简单的示例,实际应用中需要根据具体问题进行调整和优化。
q-learning实现cliffwalking-v0代码python
以下是使用Q-learning算法实现Cliff Walking游戏的Python代码:
```python
import numpy as np
import gym
env = gym.make("CliffWalking-v0")
num_states = env.observation_space.n
num_actions = env.action_space.n
Q = np.zeros((num_states, num_actions))
num_episodes = 5000
epsilon = 0.1
alpha = 0.5
gamma = 0.99
for i in range(num_episodes):
observation = env.reset()
done = False
while not done:
if np.random.uniform() < epsilon:
action = env.action_space.sample()
else:
action = np.argmax(Q[observation, :])
next_observation, reward, done, info = env.step(action)
Q[observation, action] = Q[observation, action] + alpha * (reward + gamma * np.max(Q[next_observation, :]) - Q[observation, action])
observation = next_observation
print("Q-table:")
print(Q)
def play(Q):
observation = env.reset()
done = False
while not done:
env.render()
action = np.argmax(Q[observation, :])
observation, reward, done, info = env.step(action)
env.render()
print("Reward:", reward)
play(Q)
```
请注意,这段代码使用OpenAI Gym库中的Cliff Walking环境,并使用Q-learning算法实现Agent的决策过程。Agent的决策基于Q值函数,使用epsilon贪心策略探索和exploitation。代码训练Q表格并输出结果,最后演示游戏并输出最终的奖励。
阅读全文