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Math calculator

SVD Calculator

Singular value decomposition of a small real square matrix. Same engine as Linear System. Least squares is a sibling discovery URL. Not a CAS. Runs locally.

Instant result
Result

Enter values to calculate.

Inputs
Mode
Formula
Trust summary Engine tested · Specification checked · 44/44 tests · Production surface contract 3/3 · v1.10.0
Input interpretation
Enter values to calculate.
Result
Model
A = UΣVᵀ for a small real square matrix (order 2–4).
Scope
Real square matrices
Verification
Engine tested · 44/44 tests · Production surface contract 3/3 · Specification checked · v1.10.0
Named expert review
Optional · Not performed
Specification basis
  • ISO 80000-2:2019 Quantities and units — Mathematics
Specification basis
Evidence
23 golden · 2 boundary · 19 property · Production surface contract 3/3 · Artifact integrity PASS
Production
Embedded snapshot: STALE · Last attested schema matched 1.10.0 snapshot / local build · Semantic contract ✓ · Last attestation PASS · current evidence changed · re-attestation required · Public/cache ✓ · Origin ✓ · Live production status STALE (1 capability; 163 remain CURRENT) @ 2026-09-19T00:00:17.039Z
Semantic contract
PASS

Formulas

Core equations used by this calculator.

FactorizationA = U Σ Vᵀ
Singular valuesσᵢ = ‖A vᵢ‖₂ (σ₁ ≥ σ₂ ≥ … ≥ 0)
iSquare matrices only, order ≤ 4. V from Jacobi eigen of AᵀA; U from Av/σ. Not rectangular SVD. Not a pseudoinverse. Not least squares. Float64.

How to use

1

Enter a square matrix

2×2 or 3×3. Larger composition lives at /workspace/matrix. QR and eigen are sibling discovery URLs.

2

Read σ, U, and Vᵀ

reconstruction_residual is ‖A − UΣVᵀ‖_F. rank_numeric counts σ above 10⁻¹⁵.

Example calculations

Common configurations with formula and result.

ϟ

Diagonal

diag(2, 1)

σ = 2, 1
2, 1
ϟ

Rank 1

[[1,2],[2,4]]

σ = 5, 0
rank_numeric=1

SVD calculator specification

Version 1.10.0 · Engine tested

Calculation status

Review policy · Evidence

Definition
A = U Σ Vᵀ with U and V orthogonal and Σ diagonal of singular values in descending order. This page is mode=svd on math.linear_algebra. Not a second engine. Not least squares.
What it calculates
A = UΣVᵀ for a small real square matrix (order 2–4).
Inputs
  • order
  • a11…
Outputs
  • singular_values
  • U
  • S
  • VT
  • rank_numeric
  • reconstruction_residual
Formula
A = U Σ Vᵀ
Assumptions
  • Real square matrices
  • Order ≤ 4
  • Float64
  • Not a CAS
  • Not least squares / rectangular SVD
Units
  • dimensionless
Boundary conditions
  • unknown mode (including jordan-form) → INVALID_MODE
Example
diag(2,1) → σ=2,1
Validation cases

2 published on this page · 44/44 tests · Production surface contract 3/3 · View evidence

  • order=2 a11=2 a12=0 a21=0 a22=1 → singular_values≈[2,1]
  • mode=jordan-form order=2 a11=1 a12=0 a21=0 a22=1 → INVALID_MODE
Specification basis
  • ISO 80000-2:2019 Quantities and units — Mathematics
Calculation version
1.10.0
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Frequently asked questions

Key distinctions behind the calculation.

Is this a second linear-algebra engine?

No. It is mode=svd on math.linear_algebra, the same engine as /calc/math/linear-system and /workspace/matrix.

Is this least squares or a pseudoinverse?

No. Least squares is /calc/math/least-squares on this same engine. This page only factors A = UΣVᵀ.