Recurrent Neural Network in Python: How Does It Work?

In the field of machine learning, particularly in deep learning, there are many types of neural network architectures. Each is specialized for performing a specific task. Recurrent neural networks are often used for working with text and streaming data. In this article, we will look at what they are and how you can create them using the Python language.

Python is one of the most popular programming languages, especially for machine learning development. This field opens up many opportunities for those who decide to specialize in it, through a master's degree or a Python programming course.

In this text, we will also explore learning opportunities and how good Python specialization can advance you into one of the most in-demand professional fields today. Interested? Stay with us, we are starting!

What Are Recurrent Neural Networks?

As we mentioned, recurrent neural networks (RNNs) are a type of neural network. Neural networks are an important part of deep learning, which in turn is a branch of machine learning—one of the areas of artificial intelligence study. This type of neural network specializes in processing sequential data or time series.

What does this mean? A neural network can help build predictive models based on a sequence of historical data. An example is developing a predictive model for a company's sales volume. This, in turn, helps better manage inventory and improve the company's production processes.

Recurrent neural networks are especially useful in developing natural language processing technologies.

The architecture of recurrent neural networks allows a program or application built on them to easily remember and forget the information being processed. Thus, machine learning models of this type can remember processed data at the beginning of a sequence to relate it to new data under analysis.

This also makes recurrent neural networks particularly useful for generating text. In fact, they can analyze text fragments and generate new content from them. For instance, one application is in developing predictive text applications.

How Does a Recurrent Neural Network Work?

A recurrent neural network, like any other type of neural network, consists of various layers composed of nodes or neurons. In this case, a recurrent neuron has a number of characteristics that will help us understand how this machine learning model works. Generally speaking, nodes used in other types of models can transfer information in one direction—they only pass it forward. A recurrent neuron, unlike others, can transfer information both forward and backward.

At each time step, a recurrent neuron receives information from the input of the previous step as well as from its own output, so that based on processed data, it generates its own output.

Thus, using recurrent neural networks, information from previous steps can be recovered, allowing the program to establish a connection with what is happening at the current processing moment. For practical purposes, this is not very efficient, so certain architectures must be created to apply means that optimize this process.

Each recurrent neuron that makes up the layers of an RNN has two sets of parameters: one applied to the input from the previous layer, and the other to its own output. Using backpropagation, this process can be optimized to reduce errors and improve data processing by the neural network.

Types of Recurrent Neural Networks

There are various types of recurrent neural networks depending on the format of input and output data you want to achieve:

  • One-to-Many: An RNN architecture that allows inputting data and receiving a sequence of data as output. An example is neural networks trained to describe an image. In this case, the network takes an image as input and returns descriptive text as output.
  • Many-to-One: In this case, the RNN works with a set of input data and produces a single output. Here the reverse example applies: an AI model receives an image description (e.g., an image of a dog) and returns a generated image. An example is DALL-E, a web application that allows users to input text, on which the AI generates an image.
  • Many-to-Many: In this case, as you might guess, the RNN starts with a more or less large dataset and outputs various data. An example here are text generation applications that can generate new content based on a given text, like InferKit, or more advanced applications focused on creating content for blogs and social networks, such as Dupla AI.

Thus, after reviewing the existing types of RNNs, we can outline some key areas of application:

  • Intelligent text translation
  • Intelligent chatbots
  • Sales forecasting
  • Virtual assistants
  • Image recognition

This is just a small part of what recurrent neural networks can do. To develop and advance in this field of artificial intelligence research, this type of machine learning model is combined with others, such as generative adversarial networks or convolutional networks.