LU Decomposition Calculator

LU Decomposition Calculator - Multi-Tools

LU Decomposition Calculator

Decompose a square matrix into lower (L) and upper (U) triangular matrices.

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How LU Decomposition Works

LU decomposition factors a square matrix A into:

\[ A = LU \]

where:

  • L is a lower triangular matrix with ones on the diagonal
  • U is an upper triangular matrix

Properties:

  • L has ones on the diagonal and zeros above
  • U has zeros below the diagonal
  • Not all matrices have an LU decomposition
  • If A is invertible, the decomposition is unique

Applications:

  • Solving systems of linear equations
  • Matrix inversion
  • Determinant calculation
  • Eigenvalue computation

Algorithm Steps:

  1. Initialize L as identity matrix and U as copy of A
  2. For each column j:
    • For each row i > j:
      • Calculate multiplier: L[i][j] = U[i][j] / U[j][j]
      • Subtract L[i][j] × row j from row i in U
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