Book Image

Hands-On Meta Learning with Python

By : Sudharsan Ravichandiran
Book Image

Hands-On Meta Learning with Python

By: Sudharsan Ravichandiran

Overview of this book

Meta learning is an exciting research trend in machine learning, which enables a model to understand the learning process. Unlike other ML paradigms, with meta learning you can learn from small datasets faster. Hands-On Meta Learning with Python starts by explaining the fundamentals of meta learning and helps you understand the concept of learning to learn. You will delve into various one-shot learning algorithms, like siamese, prototypical, relation and memory-augmented networks by implementing them in TensorFlow and Keras. As you make your way through the book, you will dive into state-of-the-art meta learning algorithms such as MAML, Reptile, and CAML. You will then explore how to learn quickly with Meta-SGD and discover how you can perform unsupervised learning using meta learning with CACTUs. In the concluding chapters, you will work through recent trends in meta learning such as adversarial meta learning, task agnostic meta learning, and meta imitation learning. By the end of this book, you will be familiar with state-of-the-art meta learning algorithms and able to enable human-like cognition for your machine learning models.
Table of Contents (17 chapters)
Title Page
Dedication
About Packt
Contributors
Preface
Index

Chapter 7: Meta-SGD and Reptile Algorithms


  1. Unlike MAML, in Meta-SGD, along with finding optimal parameter value, 
    , we also find the optimal learning rate, 
    , and update the direction.
  2. The learning rate is implicitly implemented in the adaptation term. So, in Meta-SGD, we don't initialize a learning rate with a small scalar value. Instead, we initialize them with random values with the same shape as
     and learn them along with 
    .
  1. The update equation of the learning rate can be expressed as 
    .
  2. Sample n tasks and run SGD for fewer iterations on each of the sampled tasks, and then update our model parameter in a direction that is common to all the tasks.
  3. The reptile update equation can be expressed as 
    .