Book Image

Hands-On Graph Neural Networks Using Python

By : Maxime Labonne
Book Image

Hands-On Graph Neural Networks Using Python

By: Maxime Labonne

Overview of this book

Graph neural networks are a highly effective tool for analyzing data that can be represented as a graph, such as networks, chemical compounds, or transportation networks. The past few years have seen an explosion in the use of graph neural networks, with their application ranging from natural language processing and computer vision to recommendation systems and drug discovery. Hands-On Graph Neural Networks Using Python begins with the fundamentals of graph theory and shows you how to create graph datasets from tabular data. As you advance, you’ll explore major graph neural network architectures and learn essential concepts such as graph convolution, self-attention, link prediction, and heterogeneous graphs. Finally, the book proposes applications to solve real-life problems, enabling you to build a professional portfolio. The code is readily available online and can be easily adapted to other datasets and apps. By the end of this book, you’ll have learned to create graph datasets, implement graph neural networks using Python and PyTorch Geometric, and apply them to solve real-world problems, along with building and training graph neural network models for node and graph classification, link prediction, and much more.
Table of Contents (25 chapters)
1
Part 1: Introduction to Graph Learning
5
Part 2: Fundamentals
10
Part 3: Advanced Techniques
18
Part 4: Applications
22
Chapter 18: Unlocking the Potential of Graph Neural Networks for Real-World Applications

Introducing heterogeneous graphs

Heterogeneous graphs are a powerful tool to represent general relationships between different entities. Having different types of nodes and edges creates graph structures that are more complex but also more difficult to learn. In particular, one of the main problems with heterogeneous networks is that features from different types of nodes or edges do not necessarily have the same meaning or dimensionality. Therefore, merging different features would destroy a lot of information. This is not the case with homogeneous graphs, where each dimension has the exact same meaning for every node or edge.

Heterogeneous graphs are a more general kind of network that can represent different types of nodes and edges. Formally, it is defined as a graph, , comprising , a set of nodes, and , a set of edges. In the heterogeneous setting, it is associated with a node-type mapping function, (where denotes the set of node types), and a link-type mapping function,...