用TensorFlow實(shí)現(xiàn)CNN識(shí)別cifar10數(shù)據(jù)集。
知識(shí)回顧:
CNN的本質(zhì)是先把數(shù)據(jù)進(jìn)行特征提取,再送進(jìn)DNN。前面特征提取的部分可以概括為CBAPD,C表示卷積(convolution),B表示批標(biāo)準(zhǔn)化(batch normalization),A表示激活(activation),P表示池化(pool),D表示(dropout)
全代碼:
import tensorflow as tf
import numpy as np
from matplotlib import pyplot as plt
from tensorflow.keras.layers import Conv2D, BatchNormalization, Activation, MaxPool2D, Dropout, Flatten, Dense
from tensorflow.keras import Model
cifar10 = tf.keras.datasets.cifar10
(x_train, y_train), (x_test, y_test) = cifar10.load_data()
x_train, x_test = x_train / 255.0, x_test / 255.0
class Baseline(Model):
def __init__(self):
super(Baseline, self).__init__()
self.c1 = Conv2D(filters=6, kernel_size=(5, 5), padding='same') # 卷積層
self.b1 = BatchNormalization() # BN層
self.a1 = Activation('relu') # 激活層
self.p1 = MaxPool2D(pool_size=(2, 2), strides=2, padding='same') # 池化層
self.d1 = Dropout(0.2) # dropout層
self.flatten = Flatten()
self.f1 = Dense(128, activation='relu')
self.d2 = Dropout(0.2)
self.f2 = Dense(10, activation='softmax')
def call(self, x):
x = self.c1(x)
x = self.b1(x)
x = self.a1(x)
x = self.p1(x)
x = self.d1(x)
x = self.flatten(x)
x = self.f1(x)
x = self.d2(x)
y = self.f2(x)
return y
model = Baseline()
model.compile(optimizer='adam',
loss=tf.keras.losses.SparseCategoricalCrossentropy(from_logits=False),
metrics=['sparse_categorical_accuracy'])
history = model.fit(x_train, y_train, batch_size=32, epochs=10, validation_data=(x_test, y_test), validation_freq=1)
model.summary()
# 搞定,畫圖,顯示訓(xùn)練集和驗(yàn)證集的acc和loss曲線
acc = history.history['sparse_categorical_accuracy']
val_acc = history.history['val_sparse_categorical_accuracy']
loss = history.history['loss']
val_loss = history.history['val_loss']
plt.subplot(1, 2, 1)
plt.plot(acc, label='Training Accuracy')
plt.plot(val_acc, label='Validation Accuracy')
plt.title('Training and Validation Accuracy')
plt.legend()
plt.subplot(1, 2, 2)
plt.plot(loss, label='Training Loss')
plt.plot(val_loss, label='Validation Loss')
plt.title('Training and Validation Loss')
plt.legend()
plt.show()
為了快速出結(jié)果,epoch只設(shè)了10,所以準(zhǔn)確率不高,batch_size設(shè)高點(diǎn),epoch設(shè)高點(diǎn),結(jié)果應(yīng)該會(huì)變很理想。
感興趣可以看看這篇!《一文極速理解深度學(xué)習(xí)》
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