Book Image

The TensorFlow Workshop

By : Matthew Moocarme, Abhranshu Bagchi, Anthony So, Anthony Maddalone
Book Image

The TensorFlow Workshop

By: Matthew Moocarme, Abhranshu Bagchi, Anthony So, Anthony Maddalone

Overview of this book

Getting to grips with tensors, deep learning, and neural networks can be intimidating and confusing for anyone, no matter their experience level. The breadth of information out there, often written at a very high level and aimed at advanced practitioners, can make getting started even more challenging. If this sounds familiar to you, The TensorFlow Workshop is here to help. Combining clear explanations, realistic examples, and plenty of hands-on practice, it’ll quickly get you up and running. You’ll start off with the basics – learning how to load data into TensorFlow, perform tensor operations, and utilize common optimizers and activation functions. As you progress, you’ll experiment with different TensorFlow development tools, including TensorBoard, TensorFlow Hub, and Google Colab, before moving on to solve regression and classification problems with sequential models. Building on this solid foundation, you’ll learn how to tune models and work with different types of neural network, getting hands-on with real-world deep learning applications such as text encoding, temperature forecasting, image augmentation, and audio processing. By the end of this deep learning book, you’ll have the skills, knowledge, and confidence to tackle your own ambitious deep learning projects with TensorFlow.
Table of Contents (13 chapters)
Preface

Metrics for Classifiers

In the previous section, you learned how to train a binary classifier to predict the right output: either 0 or 1. In Exercise 5.01, Building a Logistic Regression Model, you looked at a few samples to assess the performance of the models that were built. Usually, you would evaluate a model not just on a small subset but on the whole dataset using a performance metric such as accuracy or F1 score.

Accuracy and Null Accuracy

One of the most widely used metrics for classification problems is accuracy. Its formula is quite simple:

Figure 5.14: Formula of the accuracy metric

The maximum value for accuracy is 1, which means the model correctly predicts 100% of the cases. Its minimum value is 0, where the model can't predict any case correctly.

For a binary classifier, the number of correct predictions is the number of observations with a value of 0 or 1 as the correctly predicted value:

Figure 5.15...