Book Image

Mastering PyTorch - Second Edition

By : Ashish Ranjan Jha
4 (1)
Book Image

Mastering PyTorch - Second Edition

4 (1)
By: Ashish Ranjan Jha

Overview of this book

PyTorch is making it easier than ever before for anyone to build deep learning applications. This PyTorch deep learning book will help you uncover expert techniques to get the most out of your data and build complex neural network models. You’ll build convolutional neural networks for image classification and recurrent neural networks 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, including diffusion models. You'll not only build and train your own deep reinforcement learning models in PyTorch but also learn to optimize model training using multiple CPUs, GPUs, and mixed-precision training. You’ll deploy PyTorch models to production, including mobile devices. Finally, you’ll discover the PyTorch ecosystem and its rich set of libraries. These libraries will add another set of tools to your deep learning toolbelt, teaching you how to use fastai to prototype models and PyTorch Lightning to train models. You’ll discover libraries for AutoML and explainable AI (XAI), create recommendation systems, and build language and vision transformers with Hugging Face. By the end of this book, you'll be able to perform complex deep learning tasks using PyTorch to build smart artificial intelligence models.
Table of Contents (21 chapters)
20
Index

Building a DQN model in PyTorch

We discussed the theory behind DQNs in the previous section. In this section, we will take a hands-on approach. Using PyTorch, we will build a CNN-based DQN model that will train an agent to play the video game known as Pong. The goal of this exercise is to demonstrate how to develop DRL applications using PyTorch. Let’s get straight into the exercise.

Initializing the main and target CNN models

In this exercise, we will only show the important parts of the code for demonstration purposes. In order to access the full code, visit our GitHub repository [1]. Follow these steps:

  1. First, we need to import the necessary libraries:
    # general imports
    import cv2
    import math
    import numpy as np
    import random
    # reinforcement learning related imports
    import re
    import atari_py as ap
    from collections import deque
    from gym import make, ObservationWrapper, Wrapper
    from gym.spaces import Box
    # pytorch imports
    import torch
    import torch...