# spttrf(3) [centos man page]

```spttrf.f(3)							      LAPACK							       spttrf.f(3)

NAME
spttrf.f -

SYNOPSIS
Functions/Subroutines
subroutine spttrf (N, D, E, INFO)
SPTTRF

Function/Subroutine Documentation
subroutine spttrf (integerN, real, dimension( * )D, real, dimension( * )E, integerINFO)
SPTTRF

Purpose:

SPTTRF computes the L*D*L**T factorization of a real symmetric
positive definite tridiagonal matrix A.  The factorization may also
be regarded as having the form A = U**T*D*U.

Parameters:
N

N is INTEGER
The order of the matrix A.  N >= 0.

D

D 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**T factorization of A.

E

E is REAL 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**T factorization of A.
E can also be regarded as the superdiagonal of the unit
bidiagonal factor U from the U**T*D*U factorization of A.

INFO

INFO 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

NAG Ltd.

Date:
November 2011

Definition at line 92 of file spttrf.f.

Author
Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.2							  Tue Sep 25 2012						       spttrf.f(3)```

## Check Out this Related Man Page

```spttrf.f(3)							      LAPACK							       spttrf.f(3)

NAME
spttrf.f -

SYNOPSIS
Functions/Subroutines
subroutine spttrf (N, D, E, INFO)
SPTTRF

Function/Subroutine Documentation
subroutine spttrf (integerN, real, dimension( * )D, real, dimension( * )E, integerINFO)
SPTTRF

Purpose:

SPTTRF computes the L*D*L**T factorization of a real symmetric
positive definite tridiagonal matrix A.  The factorization may also
be regarded as having the form A = U**T*D*U.

Parameters:
N

N is INTEGER
The order of the matrix A.  N >= 0.

D

D 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**T factorization of A.

E

E is REAL 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**T factorization of A.
E can also be regarded as the superdiagonal of the unit
bidiagonal factor U from the U**T*D*U factorization of A.

INFO

INFO 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

NAG Ltd.

Date:
November 2011

Definition at line 92 of file spttrf.f.

Author
Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.2							  Tue Sep 25 2012						       spttrf.f(3)```
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