Singular value decomposition (SVD) is a popular method of matrix decomposition that reduces a complex matrix into its constituent parts so that subsequent matrix calculations are simpler.
The general equation for SVD for real-valued matrices is:
A = U * Σ * V^T
Where A represents the real m x n matrix that is being decomposed, U is a m x m matrix, Σ is an m x n diagonal matrix, and V^T (i.e. V transposed) is the transpose of an n x n matrix.
The columns of the U matrix are called the left-singular vectors of matrix A, while the columns of the V matrix are called the right-singular vectors of A. The diagonal values of the Σ matrix are the singular values of matrix A.
SVD is a commonly used method for data reduction in machine learning, particularly in unsupervised learning algorithms. It's one of the core elements of the recommender systems of international companies like Google, Facebook, Netflix and Youtube, helping them determine the order that pages appear in search results, what content and ads you see, and what shows / movies / videos you might enjoy.
