VAE算法模型python代码怎么找
时间: 2023-04-01 15:01:09 浏览: 73
你可以在网上搜索相关的教程和代码示例,或者参考一些开源的VAE算法库,例如TensorFlow、PyTorch等。同时,你也可以阅读相关的论文和书籍,深入了解VAE算法的原理和实现方式。希望这些资源能够帮助你找到VAE算法模型的Python代码。
相关问题
帮我找一下VAE算法模型的python代码
以下是一个简单的VAE算法模型的Python代码:
```python
import tensorflow as tf
from tensorflow.keras import layers
# 定义VAE模型
class VAE(tf.keras.Model):
def __init__(self, latent_dim):
super(VAE, self).__init__()
self.latent_dim = latent_dim
self.encoder = tf.keras.Sequential([
layers.InputLayer(input_shape=(28, 28, 1)),
layers.Conv2D(filters=32, kernel_size=3, strides=(2, 2), activation='relu'),
layers.Conv2D(filters=64, kernel_size=3, strides=(2, 2), activation='relu'),
layers.Flatten(),
layers.Dense(latent_dim + latent_dim),
])
self.decoder = tf.keras.Sequential([
layers.InputLayer(input_shape=(latent_dim,)),
layers.Dense(units=7*7*32, activation=tf.nn.relu),
layers.Reshape(target_shape=(7, 7, 32)),
layers.Conv2DTranspose(filters=64, kernel_size=3, strides=(2, 2), padding='same', activation='relu'),
layers.Conv2DTranspose(filters=32, kernel_size=3, strides=(2, 2), padding='same', activation='relu'),
layers.Conv2DTranspose(filters=1, kernel_size=3, strides=(1, 1), padding='same'),
])
# 定义重参数化函数
def reparameterize(self, mean, logvar):
eps = tf.random.normal(shape=mean.shape)
return eps * tf.exp(logvar * .5) + mean
# 定义前向传播函数
def call(self, inputs):
mean, logvar = tf.split(self.encoder(inputs), num_or_size_splits=2, axis=1)
z = self.reparameterize(mean, logvar)
reconstructed = self.decoder(z)
return reconstructed, mean, logvar
# 定义VAE损失函数
def vae_loss(reconstructed, inputs, mean, logvar):
reconstruction_loss = tf.reduce_mean(tf.square(inputs - reconstructed))
kl_loss = -.5 * tf.reduce_mean(1 + logvar - tf.square(mean) - tf.exp(logvar))
return reconstruction_loss + kl_loss
```
希望这个代码能够帮到你!
帮我找一下VAE算法生成数据模型的python代码
以下是VAE算法生成数据模型的Python代码:
```python
import numpy as np
import tensorflow as tf
from tensorflow import keras
from tensorflow.keras import layers
# 定义VAE模型
latent_dim = 2
encoder_inputs = keras.Input(shape=(28, 28, 1))
x = layers.Conv2D(32, 3, activation="relu", strides=2, padding="same")(encoder_inputs)
x = layers.Conv2D(64, 3, activation="relu", strides=2, padding="same")(x)
x = layers.Flatten()(x)
x = layers.Dense(16, activation="relu")(x)
z_mean = layers.Dense(latent_dim, name="z_mean")(x)
z_log_var = layers.Dense(latent_dim, name="z_log_var")(x)
encoder = keras.Model(encoder_inputs, [z_mean, z_log_var], name="encoder")
latent_inputs = keras.Input(shape=(latent_dim,))
x = layers.Dense(7 * 7 * 64, activation="relu")(latent_inputs)
x = layers.Reshape((7, 7, 64))(x)
x = layers.Conv2DTranspose(64, 3, activation="relu", strides=2, padding="same")(x)
x = layers.Conv2DTranspose(32, 3, activation="relu", strides=2, padding="same")(x)
decoder_outputs = layers.Conv2DTranspose(1, 3, activation="sigmoid", padding="same")(x)
decoder = keras.Model(latent_inputs, decoder_outputs, name="decoder")
class VAE(keras.Model):
def __init__(self, encoder, decoder, **kwargs):
super(VAE, self).__init__(**kwargs)
self.encoder = encoder
self.decoder = decoder
def train_step(self, data):
if isinstance(data, tuple):
data = data[]
with tf.GradientTape() as tape:
z_mean, z_log_var = self.encoder(data)
z = self.sampling((z_mean, z_log_var))
reconstruction = self.decoder(z)
reconstruction_loss = tf.reduce_mean(
keras.losses.binary_crossentropy(data, reconstruction)
)
reconstruction_loss *= 28 * 28
kl_loss = 1 + z_log_var - tf.square(z_mean) - tf.exp(z_log_var)
kl_loss = tf.reduce_mean(kl_loss)
kl_loss *= -.5
total_loss = reconstruction_loss + kl_loss
grads = tape.gradient(total_loss, self.trainable_weights)
self.optimizer.apply_gradients(zip(grads, self.trainable_weights))
return {
"loss": total_loss,
"reconstruction_loss": reconstruction_loss,
"kl_loss": kl_loss,
}
def call(self, inputs):
z_mean, z_log_var = self.encoder(inputs)
z = self.sampling((z_mean, z_log_var))
return self.decoder(z)
def sampling(self, args):
z_mean, z_log_var = args
batch = tf.shape(z_mean)[]
dim = tf.shape(z_mean)[1]
epsilon = tf.keras.backend.random_normal(shape=(batch, dim))
return z_mean + tf.exp(.5 * z_log_var) * epsilon
# 加载MNIST数据集
(x_train, _), (x_test, _) = keras.datasets.mnist.load_data()
mnist_digits = np.concatenate([x_train, x_test], axis=)
mnist_digits = np.expand_dims(mnist_digits, -1).astype("float32") / 255
# 训练VAE模型
vae = VAE(encoder, decoder)
vae.compile(optimizer=keras.optimizers.Adam())
vae.fit(mnist_digits, epochs=30, batch_size=128)
# 生成新的手写数字
n = 15
digit_size = 28
figure = np.zeros((digit_size * n, digit_size * n))
grid_x = np.linspace(-4, 4, n)
grid_y = np.linspace(-4, 4, n)[::-1]
for i, yi in enumerate(grid_y):
for j, xi in enumerate(grid_x):
z_sample = np.array([[xi, yi]])
x_decoded = vae.decoder.predict(z_sample)
digit = x_decoded[].reshape(digit_size, digit_size)
figure[i * digit_size : (i + 1) * digit_size,
j * digit_size : (j + 1) * digit_size] = digit
plt.figure(figsize=(10, 10))
plt.imshow(figure, cmap="Greys_r")
plt.show()
```