Book Image

Data Science with Python

By : Rohan Chopra, Aaron England, Mohamed Noordeen Alaudeen
Book Image

Data Science with Python

By: Rohan Chopra, Aaron England, Mohamed Noordeen Alaudeen

Overview of this book

Data Science with Python begins by introducing you to data science and teaches you to install the packages you need to create a data science coding environment. You will learn three major techniques in machine learning: unsupervised learning, supervised learning, and reinforcement learning. You will also explore basic classification and regression techniques, such as support vector machines, decision trees, and logistic regression. As you make your way through the book, you will understand the basic functions, data structures, and syntax of the Python language that are used to handle large datasets with ease. You will learn about NumPy and pandas libraries for matrix calculations and data manipulation, discover how to use Matplotlib to create highly customizable visualizations, and apply the boosting algorithm XGBoost to make predictions. In the concluding chapters, you will explore convolutional neural networks (CNNs), deep learning algorithms used to predict what is in an image. You will also understand how to feed human sentences to a neural network, make the model process contextual information, and create human language processing systems to predict the outcome. By the end of this book, you will be able to understand and implement any new data science algorithm and have the confidence to experiment with tools or libraries other than those covered in the book.
Table of Contents (10 chapters)

Recurrent Neural Networks (RNNs)

Until now, none of the problems we discussed had a temporal dependence, which means that the prediction depends not only on the current input but also on the past inputs. For example, in the case of the dog vs. cat classifier, we only needed the picture of the dog to classify it as a dog. No other information or images were required. Instead, if you want to make a classifier that predicts if a dog is walking or standing, you will require multiple images in a sequence or a video to figure out what the dog is doing. RNNs are like the fully connected networks that we talked about. The only change is that an RNN has memory that stores information about the previous inputs as states. The outputs of the hidden layers are fed in as inputs for the next input.

Figure 7.33: Representation of recurrent neural network

From the image, you can understand how the outputs of the hidden layers are used as inputs for the next input. This acts as a memory element...