CPTTRF (3) - Linux Manuals
NAME
cpttrf.f -
SYNOPSIS
Functions/Subroutines
subroutine cpttrf (N, D, E, INFO)
CPTTRF
Function/Subroutine Documentation
subroutine cpttrf (integerN, real, dimension( * )D, complex, dimension( * )E, integerINFO)
CPTTRF
Purpose:
-
CPTTRF computes the L*D*L**H factorization of a complex Hermitian positive definite tridiagonal matrix A. The factorization may also be regarded as having the form A = U**H *D*U.
Parameters:
-
N
N is INTEGER The order of the matrix A. N >= 0.
DD is REAL array, dimension (N) On entry, the n diagonal elements of the tridiagonal matrix A. On exit, the n diagonal elements of the diagonal matrix D from the L*D*L**H factorization of A.
EE is COMPLEX array, dimension (N-1) On entry, the (n-1) subdiagonal elements of the tridiagonal matrix A. On exit, the (n-1) subdiagonal elements of the unit bidiagonal factor L from the L*D*L**H factorization of A. E can also be regarded as the superdiagonal of the unit bidiagonal factor U from the U**H *D*U factorization of A.
INFOINFO is INTEGER = 0: successful exit < 0: if INFO = -k, the k-th argument had an illegal value > 0: if INFO = k, the leading minor of order k is not positive definite; if k < N, the factorization could not be completed, while if k = N, the factorization was completed, but D(N) <= 0.
Author:
-
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
- September 2012
Definition at line 93 of file cpttrf.f.
Author
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