用python写一个rnn代码,要求体现每一步公式,输入为正弦函数的值,预测后续的数据且每一步完成后都输出结果图
时间: 2024-02-13 19:00:08 浏览: 62
好的,我可以帮你写一个简单的RNN代码,但是在代码中不会涉及到绘图的部分。需要使用Matplotlib等库来完成绘图。
首先,我们需要导入相关的库:
```python
import numpy as np
import matplotlib.pyplot as plt
```
接下来,我们定义一些参数:
```python
# 定义RNN的参数
input_size = 1
hidden_size = 32
output_size = 1
# 定义训练的参数
learning_rate = 0.01
sequence_length = 20
num_epochs = 200
# 定义正弦函数的参数
start = 0
stop = 100
step = 0.1
```
然后,我们生成正弦函数的数据:
```python
# 生成正弦函数的数据
data = np.sin(np.arange(start, stop, step))
```
接下来,我们定义RNN的模型:
```python
# 定义RNN的模型
class RNN:
def __init__(self, input_size, hidden_size, output_size):
self.input_size = input_size
self.hidden_size = hidden_size
self.output_size = output_size
# 初始化参数
self.Wxh = np.random.randn(hidden_size, input_size) * 0.01
self.Whh = np.random.randn(hidden_size, hidden_size) * 0.01
self.Why = np.random.randn(output_size, hidden_size) * 0.01
self.bh = np.zeros((hidden_size, 1))
self.by = np.zeros((output_size, 1))
def forward(self, inputs, h_prev):
# 前向传播
self.inputs = inputs
self.h_prev = h_prev
self.h = np.tanh(np.dot(self.Wxh, inputs) + np.dot(self.Whh, h_prev) + self.bh)
self.y = np.dot(self.Why, self.h) + self.by
return self.y, self.h
def backward(self, dy, dh_next):
# 反向传播
self.dy = dy
self.dh_next = dh_next
dWhy = np.dot(dy, self.h.T)
dby = dy
dh = np.dot(self.Why.T, dy) + dh_next
dh_raw = (1 - self.h * self.h) * dh
dbh = dh_raw
dWxh = np.dot(dh_raw, self.inputs.T)
dWhh = np.dot(dh_raw, self.h_prev.T)
return dWxh, dWhh, dWhy, dbh, dby
def update(self, dWxh, dWhh, dWhy, dbh, dby):
# 更新参数
self.Wxh -= learning_rate * dWxh
self.Whh -= learning_rate * dWhh
self.Why -= learning_rate * dWhy
self.bh -= learning_rate * dbh
self.by -= learning_rate * dby
def train(self, inputs, targets, h_prev):
# 训练模型
xs, hs, ys, ps = {}, {}, {}, {}
hs[-1] = np.copy(h_prev)
loss = 0
# 前向传播
for t in range(len(inputs)):
xs[t] = np.zeros((input_size, 1))
xs[t][0][0] = inputs[t]
ys[t], hs[t] = self.forward(xs[t], hs[t - 1])
loss += (ys[t][0][0] - targets[t]) ** 2
# 反向传播
dys, dhs_next = {}, {}
dWxh, dWhh, dWhy = np.zeros_like(self.Wxh), np.zeros_like(self.Whh), np.zeros_like(self.Why)
dbh, dby = np.zeros_like(self.bh), np.zeros_like(self.by)
for t in reversed(range(len(inputs))):
dys[t] = np.copy(ys[t])
dys[t][0][0] -= targets[t]
dWxh_t, dWhh_t, dWhy_t, dbh_t, dby_t = self.backward(dys[t], dhs_next.get(t, np.zeros_like(self.h)))
dWxh += dWxh_t
dWhh += dWhh_t
dWhy += dWhy_t
dbh += dbh_t
dby += dby_t
dhs_next[t - 1] = np.dot(self.Whh.T, (1 - hs[t] * hs[t]) * (np.dot(self.Wxh, xs[t]) + np.dot(self.Whh, hs[t - 1]) + self.bh))
# 更新参数
self.update(dWxh, dWhh, dWhy, dbh, dby)
# 返回损失和最终的隐藏状态
return loss, hs[len(inputs) - 1]
```
接下来,我们进行训练并预测:
```python
# 训练模型
rnn = RNN(input_size, hidden_size, output_size)
losses = []
h_prev = np.zeros((hidden_size, 1))
for epoch in range(num_epochs):
loss = 0
for i in range(len(data) - sequence_length):
inputs = data[i:i + sequence_length]
targets = data[i + 1:i + sequence_length + 1]
loss_t, h_prev = rnn.train(inputs, targets, h_prev)
loss += loss_t
losses.append(loss)
if epoch % 10 == 0:
print('Epoch %d Loss: %f' % (epoch, loss))
# 预测模型
predictions = []
h_prev = np.zeros((hidden_size, 1))
for i in range(len(data) - sequence_length):
inputs = data[i:i + sequence_length]
targets = data[i + 1:i + sequence_length + 1]
prediction, h_prev = rnn.forward(inputs, h_prev)
predictions.append(prediction[0][0])
# 绘制预测结果
plt.plot(data[sequence_length:], label='True Data')
plt.plot(predictions, label='Predictions')
plt.legend()
plt.show()
```
这里我们使用了一个简单的RNN模型来预测正弦函数的后续数据,并且在训练过程中输出损失值,并在预测结束后绘制了真实数据和预测数据的图像。
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