Understanding And Implementing Dropout In TensorFlow And Keras

栏目: IT技术 · 发布时间: 4年前

Understanding And Implementing Dropout In TensorFlow And Keras

Implementing Dropout Technique

Using TensorFlow and Keras, we are equipped with the tools to implement a neural network that utilizes the dropout technique by including dropout layers within the neural network architecture.

We only need to add one line to include a dropout layer within a more extensive neural network architecture. The Dropout class takes a few arguments, but for now, we are only concerned with the ‘rate’ argument. The dropout rate is a hyperparameter that represents the likelihood of a neuron activation been set to zero during a training step. The rate argument can take values between 0 and 1.

keras.layers.Dropout(rate=0.2)

From this point onwards, we will go through small steps taken to implement, train and evaluate a neural network.

  1. Load tools and libraries utilized, Keras and TensorFlow
import tensorflow as tf
from tensorflow import keras

2. Load the FashionMNIST dataset, normalize images and partition dataset into test, training and validation data.

(train_images, train_labels),(test_images, test_labels) = keras.datasets.fashion_mnist.load_data()
train_images = train_images / 255.0
test_images = test_images / 255.0
validation_images = train_images[:5000]
validation_labels = train_labels[:5000]

3. Create a custom model that includes a dropout layer using the Keras Model Class API.

class CustomModel(keras.Model):
 def __init__(self, **kwargs):
 super().__init__(**kwargs)
 self.input_layer = keras.layers.Flatten(input_shape=(28,28))
 self.hidden1 = keras.layers.Dense(200, activation='relu')
 self.hidden2 = keras.layers.Dense(100, activation='relu')
 self.hidden3 = keras.layers.Dense(60, activation='relu')
 self.output_layer = keras.layers.Dense(10, activation='softmax')
 self.dropout_layer = keras.layers.Dropout(rate=0.2)

 def call(self, input):
 input_layer = self.input_layer(input)
 input_layer = self.dropout_layer(input_layer)
 hidden1 = self.hidden1(input_layer)
 hidden1 = self.dropout_layer(hidden1)
 hidden2 = self.hidden2(hidden1)
 hidden2 = self.dropout_layer(hidden2)
 hidden3 = self.hidden3(hidden2)
 hidden3 = self.dropout_layer(hidden3)
 output_layer = self.output_layer(hidden3)
 return output_layer

4. Load the implemented model and initialize both optimizers and hyperparameters.

model = CustomModel()
sgd = keras.optimizers.SGD(lr=0.01)
model.compile(loss="sparse_categorical_crossentropy", optimizer=sgd, metrics=["accuracy"])

5. Train the model for a total of 60 epochs

model.fit(train_images, train_labels, epochs=60, validation_data=(validation_images, validation_labels))

6. Evaluate the model on the test dataset

model.evaluate(test_images, test_labels)

The result of the evaluation will look similar to the example evaluation result below:

10000/10000 [==============================] - 0s 34us/sample - loss: 0.3230 - accuracy: 0.8812[0.32301584649085996, 0.8812]

The accuracy shown in the evaluation result example corresponds to the accuracy of our model of 88%.

With some fine-tuning and training with more significant epoch numbers, the accuracy could be increased by a few percentages.

Here’s a GitHub repository for the code presented in this article.


以上就是本文的全部内容,希望本文的内容对大家的学习或者工作能带来一定的帮助,也希望大家多多支持 码农网

查看所有标签

猜你喜欢:

本站部分资源来源于网络,本站转载出于传递更多信息之目的,版权归原作者或者来源机构所有,如转载稿涉及版权问题,请联系我们

Python基础教程

Python基础教程

[挪] Magnus Lie Hetland / 袁国忠 / 人民邮电出版 / 2018-2-1 / CNY 99.00

本书包括Python程序设计的方方面面:首先从Python的安装开始,随后介绍了Python的基础知识和基本概念,包括列表、元组、字符串、字典以及各种语句;然后循序渐进地介绍了一些相对高级的主题,包括抽象、异常、魔法方法、属性、迭代器;此后探讨了如何将Python与数据库、网络、C语言等工具结合使用,从而发挥出Python的强大功能,同时介绍了Python程序测试、打包、发布等知识;最后,作者结合......一起来看看 《Python基础教程》 这本书的介绍吧!

随机密码生成器
随机密码生成器

多种字符组合密码

Base64 编码/解码
Base64 编码/解码

Base64 编码/解码

正则表达式在线测试
正则表达式在线测试

正则表达式在线测试