lu (MathScript Function) (Windows, Not in Base Package)

LabVIEW 8.5 Help
August 2007

NI Part Number:
371361D-01

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Member of the linalgebra class.

Syntax

l = lu(a)

[l, u] = lu(a)

[l, u, p] = lu(a)

Decomposes a square matrix into upper and lower triangular matrices using Gaussian factorization.

Name	Description
a	Specifies a square matrix.

Name	Description
l	Returns a permuted, lower triangular matrix. If you specify [l, u, p] = lu(a), l returns the lower triangular matrix with 1 on the diagonal such that lu = pa. If you specify [l, u] = lu(a), l returns a matrix equal to p'*m, where m is the lower triangular matrix with 1 on the diagonal. If you specify l = lu(a), l returns the strict lower triangle of the lower triangular matrix and the upper triangle of u in the same matrix. l is a matrix of the same size as a.
u	Returns an upper triangular matrix such that lu = pa. u is a matrix of the same size as a.
p	Returns a permutation matrix such that lu = pa. The LU-factorization of p'*a thus works without row interchanges.

A = [-6, 17; 3, 8]
[L, U] = lu(A)
B = L*U

Name	Description
l	Returns a permuted, lower triangular matrix. If you specify [l, u, p] = lu(a), l returns the lower triangular matrix with 1 on the diagonal such that lu = pa. If you specify [l, u] = lu(a), l returns a matrix equal to p'*m, where m is the lower triangular matrix with 1 on the diagonal. If you specify l = lu(a), l returns the strict lower triangle of the lower triangular matrix and the upper triangle of u in the same matrix. l is a matrix of the same size as a.
u	Returns an upper triangular matrix such that lu = pa. u is a matrix of the same size as a.
p	Returns a permutation matrix such that lu = pa. The LU-factorization of p'*a thus works without row interchanges.