A perceptron is a single-layer neural network for supervised learning. A neural network is a computer that mimics the way a human brain works. Supervised learning, meanwhile, is a machine learning (ML) technique that requires a human to train a computer by giving it data to get the desired results.
A perceptron has four main parts that we will describe in greater detail in the following section. These are input values, weights and bias, the net sum, and an activation function.
Read More about the “Perceptron”
As a simplified neural network, perceptrons play a critical role in binary classification. A perceptron classifies data into two parts (0s and 1s)—a computer’s primary language—binary. Because of that, perceptrons are also known as “linear binary classifiers.”
What Are the Parts of a Perceptron?
Before you can understand how a preceptor works, you need to know its components first. The perceptron’s parts are:
- Input values: These refer to the data that humans feed to the computer to get the desired output. Think of them as the books you read to learn about a particular topic.
- Weights and bias: These refer to how much each input should affect the output. They are multiplied by the input values before the net sum is computed.
- Net sum: After multiplying the input values with their corresponding weights and bias, the products are added together to get this number.
- Activation function: This applies a step rule to convert the numerical output into +1 or -1 or check if the output is greater than zero or not.
How Does a Perceptron Work?
This diagram shows how a perceptron works:
The first step is to multiply the inputs to the weights. Once that is done, add the products together to get the weighted sum. Apply the activation function to the sum to classify the data.
Perceptrons need weights and bias. Why? The weight shows the strength of each node. A bias value, meanwhile, lets you shift the activation function curve up or down. But why do you need an activation function? Because a perceptron uses binary, you need to separate values into two parts only. The activation function does just that. It maps the inputs into the required values like (0, 1) or (-1, 1).
What Is a Perceptron For?
Perceptrons can be used for recommending medical diagnoses or any data processing task that requires separating inputs into two categories.
In medicine, perceptrons can be used to decide if patients need to take a particular drug or not for their condition. Data from previous patients who have taken the drug are used as inputs fed to a perceptron. Once the computation is done, the computer provides an exact output.
How Did Perceptrons Come About?
The perceptron algorithm was invented as far back as 1958 by Frank Rosenblatt. While it was supposed to be a machine instead of a program, it was implemented in custom-built hardware, such as the “Mark 1 perceptron,” which was designed for image recognition.
The U.S. Office of Naval Research funded the making of the perceptron. The first perceptron was built at the Cornell Aeronautical Laboratory.
While the first perceptron seemed promising, experts proved that it could not be trained to recognize many pattern classes. That caused the field of neural network research to stagnate for many years until experts deemed that a neural network with two or more layers or a multilayer perceptron could work.