Neural networks are a type of machine learning algorithm that are inspired by the human brain. They are used to learn from data and make predictions. Neural networks are made up of many interconnected nodes, which are called neurons. Neurons receive input from other neurons, process that input, and then send their output to other neurons.
The mathematics of neural networks is based on linear algebra, calculus, and probability theory. Linear algebra is used to represent the data that is fed into the neural network. Calculus is used to optimize the parameters of the neural network. Probability theory is used to understand the uncertainty in the predictions made by the neural network.
Here are some of the key concepts in the mathematics of neural networks and deep learning:
Linear algebra: Linear algebra is used to represent the data that is fed into the neural network, as well as the weights and biases of the neurons.
Calculus: Calculus is used to optimize the parameters of the neural network. This process is called backpropagation.
Probability theory: Probability theory is used to understand the uncertainty in the predictions made by the neural network.
Here is a more detailed explanation of how these concepts work together:
Data representation: The data that is fed into a neural network is represented as a matrix. Each row of the matrix represents a data point, and each column represents a feature.
Forward propagation: In the forward propagation step, the data is passed through the neural network. The input data is multiplied by the weights of the first layer, and then a bias is added. The result is then passed through an activation function, which produces the output of the first layer. This process is repeated for each layer of the neural network until the output layer is reached.
Backpropagation: In the backpropagation step, the error between the predicted output and the actual output is calculated. This error is then used to update the weights and biases of the neural network. The update is done using gradient descent, which is a mathematical optimization algorithm.
Optimization: The process of updating the weights and biases of the neural network is called optimization. The goal of optimization is to find the set of weights and biases that minimizes the error between the predicted output and the actual output.
This video provides a comprehensive overview of the mathematics behind neural networks and deep learning. It covers essential topics like prerequisites, neural networks as functions, backpropagation, the four critical equations of backpropagation, vectorization, and stochastic gradient descent. By understanding these mathematical concepts, you can gain a deeper appreciation for how neural networks work and how they are trained.