Book Image

Mastering PyTorch

By : Ashish Ranjan Jha
Book Image

Mastering PyTorch

By: Ashish Ranjan Jha

Overview of this book

Deep learning is driving the AI revolution, and PyTorch is making it easier than ever before for anyone to build deep learning applications. This PyTorch book will help you uncover expert techniques to get the most out of your data and build complex neural network models. The book starts with a quick overview of PyTorch and explores using convolutional neural network (CNN) architectures for image classification. You'll then work with recurrent neural network (RNN) architectures and transformers for sentiment analysis. As you advance, you'll apply deep learning across different domains, such as music, text, and image generation using generative models and explore the world of generative adversarial networks (GANs). You'll not only build and train your own deep reinforcement learning models in PyTorch but also deploy PyTorch models to production using expert tips and techniques. Finally, you'll get to grips with training large models efficiently in a distributed manner, searching neural architectures effectively with AutoML, and rapidly prototyping models using PyTorch and fast.ai. By the end of this PyTorch book, you'll be able to perform complex deep learning tasks using PyTorch to build smart artificial intelligence models.
Table of Contents (20 chapters)
1
Section 1: PyTorch Overview
4
Section 2: Working with Advanced Neural Network Architectures
8
Section 3: Generative Models and Deep Reinforcement Learning
13
Section 4: PyTorch in Production Systems

Understanding deep Q-learning

Instead of creating a Q-values table, DQN uses a deep neural network (DNN) that outputs a Q-value for a given state-action pair. DQN is used with complex environments such as video games, where there are far too many states for them to be managed in a Q-values table. The current image frame of the video game is used to represent the current state and is fed as input to the underlying DNN model, together with the current action.

The DNN outputs a scalar Q-value for each such input. In practice, instead of just passing the current image frame, N number of neighboring image frames in a given time window are passed as input to the model.

We are using a DNN to solve an RL problem. This has an inherent concern. While working with DNNs, we have always worked with independent and identically distributed (iid) data samples. However, in RL, every current output impacts the next input. For example, in the case of Q-learning, the Bellman equation itself suggests...