keras基于多层感知器的softmax多分类
# 基于多层感知器的softmax多分类：
```
from keras.models import Sequential
from keras.layers import Dense, Dropout, Activation
from keras.optimizers import SGD
import numpy as np
x_train = np.random.random((1000, 20))
y_train = keras.utils.to_categorical(np.random.randint(10, size=(1000, 1)), num_classes=10)
x_test = np.random.random((100, 20))
y_test = keras.utils.to_categorical(np.random.randint(10, size=(100, 1)), num_classes=10)
model = Sequential()
model.add(Dense(64, activation=\'relu\',input_dim=20)
model.add(Dropout(0.5))
model.add(Dense(64, activation=\'relu\'))
model.add(Dropout(0.5))
model.add(Dense(10, activation=\'softmax\'))
sgd = SGD(lr=0.01, decay=1e-6, momentum=0.9, nesterov=True)
model.compile(loss=\'categorical_crossentropy\',optimizer=sgd,
metrics=[\'accuracy\'])
model.fit(x_train, y_train,epochs=20,batch_size=128)
score = model.evaluate(x_test, y_test, batch_size=128)
```
# MLP的二分类：
```
import numpy as np
from keras.models import Sequential
from keras.layers import Dense, Dropout
x_train = np.random.random((1000, 20))
y_train = np.random.randint(2, size=(1000, 1))
x_test = np.random.random((100, 20))
y_test = np.random.randint(2, size=(100, 1))
model = Sequential()
model.add(Dense(64, input_dim=20, activation=\'relu\'))
model.add(Dropout(0.5))
model.add(Dense(64, activation=\'relu\'))
model.add(Dropout(0.5))
model.add(Dense(1, activation=\'sigmoid\'))
model.compile(loss=\'binary_crossentropy\',
optimizer=\'rmsprop\',
metrics=[\'accuracy\'])
model.fit(x_train, y_train,
epochs=20,
batch_size=128)
score = model.evaluate(x_test, y_test, batch_size=128)
```
# 类似VGG的卷积神经网络：
```
import numpy as np
import keras
from keras.models import Sequential
from keras.layers import Dense, Dropout, Flatten
from keras.layers import Conv2D, MaxPooling2D
from keras.optimizers import SGD
x_train = np.random.random((100, 100, 100, 3))
y_train = keras.utils.to_categorical(np.random.randint(10, size=(100, 1)), num_classes=10)
x_test = np.random.random((20, 100, 100, 3))
y_test = keras.utils.to_categorical(np.random.randint(10, size=(20, 1)), num_classes=10)
model = Sequential()
model.add(Conv2D(32, (3, 3), activation=\'relu\', input_shape=(100, 100, 3)))
model.add(Conv2D(32, (3, 3), activation=\'relu\'))
model.add(MaxPooling2D(pool_size=(2, 2)))
model.add(Dropout(0.25))
model.add(Conv2D(64, (3, 3), activation=\'relu\'))
model.add(Conv2D(64, (3, 3), activation=\'relu\'))
model.add(MaxPooling2D(pool_size=(2, 2)))
model.add(Dropout(0.25))
model.add(Flatten())
model.add(Dense(256, activation=\'relu\'))
model.add(Dropout(0.5))
model.add(Dense(10, activation=\'softmax\'))
sgd = SGD(lr=0.01, decay=1e-6, momentum=0.9, nesterov=True)
model.compile(loss=\'categorical_crossentropy\', optimizer=sgd)
model.fit(x_train, y_train, batch_size=32, epochs=10)
score = model.evaluate(x_test, y_test, batch_size=32)
```
# 使用LSTM的序列分类
```
from keras.models import Sequential
from keras.layers import Dense, Dropout
from keras.layers import Embedding
from keras.layers import LSTM
model = Sequential()
model.add(Embedding(max_features, output_dim=256))
model.add(LSTM(128))
model.add(Dropout(0.5))
model.add(Dense(1, activation=\'sigmoid\'))
model.compile(loss=\'binary_crossentropy\',
optimizer=\'rmsprop\',
metrics=[\'accuracy\'])
model.fit(x_train, y_train, batch_size=16, epochs=10)
score = model.evaluate(x_test, y_test, batch_size=16)
```
# 使用1D卷积的序列分类
```
from keras.models import Sequential
from keras.layers import Dense, Dropout
from keras.layers import Embedding
from keras.layers import Conv1D, GlobalAveragePooling1D, MaxPooling1D
model = Sequential()
model.add(Conv1D(64, 3, activation=\'relu\', input_shape=(seq_length, 100)))
model.add(Conv1D(64, 3, activation=\'relu\'))
model.add(MaxPooling1D(3))
model.add(Conv1D(128, 3, activation=\'relu\'))
model.add(Conv1D(128, 3, activation=\'relu\'))
model.add(GlobalAveragePooling1D())
model.add(Dropout(0.5))
model.add(Dense(1, activation=\'sigmoid\'))
model.compile(loss=\'binary_crossentropy\',
optimizer=\'rmsprop\',
metrics=[\'accuracy\'])
model.fit(x_train, y_train, batch_size=16, epochs=10)
score = model.evaluate(x_test, y_test, batch_size=16)
```