Basic HTML version of Foils prepared 6 December 96

Foil 38 Full LU Decomposition

From Full Matrices - December 4, 1995 CPS615 Basic Simulation Track for Computational Science -- Fall Semester 95. by Geoffrey C. Fox, Nancy J. McCracken


We wish to decompose the matrix A into the product LU, where L is a lower triangular matrix with 1's on the main diagonal, and U is an upper triangular matrix.
We assume A is a full M by M matrix.
In general, pivoting is necessary to ensure numerical stability.
LU decomposition is often used in the solution of systems of linear equations, Ax = b. The equations can be written as two triangular systems,
    • Ly = b, and Ux = y
The first equation is solved for y by forward reduction, and the solution x is then obtained from the second equation by back substitution.



© on Tue Oct 7 1997