Book Image

Natural Language Processing with TensorFlow

By : Motaz Saad, Thushan Ganegedara
Book Image

Natural Language Processing with TensorFlow

By: Motaz Saad, Thushan Ganegedara

Overview of this book

Natural language processing (NLP) supplies the majority of data available to deep learning applications, while TensorFlow is the most important deep learning framework currently available. Natural Language Processing with TensorFlow brings TensorFlow and NLP together to give you invaluable tools to work with the immense volume of unstructured data in today’s data streams, and apply these tools to specific NLP tasks. Thushan Ganegedara starts by giving you a grounding in NLP and TensorFlow basics. You'll then learn how to use Word2vec, including advanced extensions, to create word embeddings that turn sequences of words into vectors accessible to deep learning algorithms. Chapters on classical deep learning algorithms, like convolutional neural networks (CNN) and recurrent neural networks (RNN), demonstrate important NLP tasks as sentence classification and language generation. You will learn how to apply high-performance RNN models, like long short-term memory (LSTM) cells, to NLP tasks. You will also explore neural machine translation and implement a neural machine translator. After reading this book, you will gain an understanding of NLP and you'll have the skills to apply TensorFlow in deep learning NLP applications, and how to perform specific NLP tasks.
Table of Contents (16 chapters)
Natural Language Processing with TensorFlow
Contributors
Preface
Index

Improving LSTMs – beam search


As we saw earlier, the generated text can be improved. Now let's see if beam search, which we discussed in Chapter 7, Long Short-Term Memory Networks, might help to improve the performance. In beam search, we will look ahead a number of steps (called a beam) and get the beam (that is, a sequence of bigrams) that has the highest joint probability calculated separately for each beam. The joint probability is calculated by multiplying the prediction probabilities of each predicted bigram in a beam. Note that this is a greedy search, meaning that we will calculate the best candidates at each depth of the tree iteratively, as the tree grows. It should be noted that this search will not result in the globally best beam.

Implementing beam search

To implement beam search, we only have to change the text generation technique. Training and validation operations stay the same. However the code will be more complicated than the text generation operation flow we saw earlier...