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Please note that the recommended version of Scilab is 6.0.1. This page might be outdated.
See the recommended documentation of this function

Scilab help >> Sparse Matrix > Sparse Decompositions > spchol

spchol

sparse cholesky factorization

Calling Sequence

[R,P] = spchol(X)

Arguments

X

symmetric positive definite real sparse matrix

P

permutation matrix

R

cholesky factor

Description

[R,P] = spchol(X) produces a lower triangular matrix R such that P*R*R'*P' = X.

Examples

X=[
3.,  0.,  0.,  2.,  0.,  0.,  2.,  0.,  2.,  0.,  0. ;
0.,  5.,  4.,  0.,  0.,  0.,  0.,  0.,  0.,  0.,  0. ;
0.,  4.,  5.,  0.,  0.,  0.,  0.,  0.,  0.,  0.,  0. ;
2.,  0.,  0.,  3.,  0.,  0.,  2.,  0.,  2.,  0.,  0. ;
0.,  0.,  0.,  0. , 5.,  0.,  0.,  0.,  0.,  0.,  4. ;
0.,  0.,  0.,  0.,  0.,  4.,  0.,  3.,  0.,  3.,  0. ;
2.,  0.,  0.,  2.,  0.,  0.,  3.,  0.,  2.,  0.,  0. ;
0.,  0.,  0.,  0.,  0.,  3.,  0.,  4.,  0.,  3.,  0. ;
2.,  0.,  0.,  2.,  0.,  0.,  2.,  0.,  3.,  0.,  0. ;
0.,  0.,  0.,  0.,  0.,  3.,  0.,  3.,  0.,  4.,  0. ;
0.,  0.,  0.,  0.,  4.,  0.,  0.,  0.,  0.,  0.,  5.];
X=sparse(X);[R,P] = spchol(X);
max(P*R*R'*P'-X)

See Also

  • sparse — sparse matrix definition
  • lusolve — sparse linear system solver
  • luget — extraction of sparse LU factors
  • chol — Cholesky factorization
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Last updated:
Mon Oct 01 17:41:08 CEST 2012