SVD — Singular Value Decomposition
Singular value decomposition (SVD) factors any matrix A into UΣVᵀ where U and V are orthogonal and Σ contains the singular values, and this calculator computes all three matrices. Shows U (left singular vectors), Σ (singular values), and V (right singular vectors) with rank and condition number.
Singular Value Decomposition A = UΣVᵀ
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Singular Value Decomposition
SVD is one of the most important matrix factorizations. Every real m×n matrix A can be written as:
- U: m×m orthogonal matrix (left singular vectors)
- Σ: m×n diagonal matrix (non-negative singular values σ₁ ≥ σ₂ ≥ ... ≥ 0)
- V: n×n orthogonal matrix (right singular vectors)
Applications
- Image compression (low-rank approximation)
- Principal Component Analysis (PCA)
- Pseudoinverse and least-squares solutions
- Numerical rank determination
- Condition number: κ = σ₁/σₙ (ratio of largest to smallest non-zero singular value)
What Do U, Σ, and V Mean?
U and V are orthogonal matrices (their columns are perpendicular unit vectors), and Σ (sigma) is a diagonal matrix containing the "singular values" — numbers that describe how much the matrix stretches space in each direction. Unlike eigenvalues, SVD works on any matrix, not just square ones.
Worked Example (2×2)
For a diagonal matrix like A = [[3,0],[0,2]], SVD is straightforward: U and V are both the identity matrix, and Σ = [[3,0],[0,2]] — the singular values are simply the diagonal entries, since the matrix doesn't rotate anything, only stretches it.
Frequently Asked Questions
Related Calculators
- Eigenvalue Calculator — a related decomposition for square matrices
- QR Decomposition Calculator — another way to break a matrix into simpler parts