# spptrs(3) [centos man page]

```spptrs.f(3)							      LAPACK							       spptrs.f(3)

NAME
spptrs.f -

SYNOPSIS
Functions/Subroutines
subroutine spptrs (UPLO, N, NRHS, AP, B, LDB, INFO)
SPPTRS

Function/Subroutine Documentation
subroutine spptrs (characterUPLO, integerN, integerNRHS, real, dimension( * )AP, real, dimension( ldb, * )B, integerLDB, integerINFO)
SPPTRS

Purpose:

SPPTRS solves a system of linear equations A*X = B with a symmetric
positive definite matrix A in packed storage using the Cholesky
factorization A = U**T*U or A = L*L**T computed by SPPTRF.

Parameters:
UPLO

UPLO is CHARACTER*1
= 'U':  Upper triangle of A is stored;
= 'L':  Lower triangle of A is stored.

N

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

NRHS

NRHS is INTEGER
The number of right hand sides, i.e., the number of columns
of the matrix B.  NRHS >= 0.

AP

AP is REAL array, dimension (N*(N+1)/2)
The triangular factor U or L from the Cholesky factorization
A = U**T*U or A = L*L**T, packed columnwise in a linear
array.  The j-th column of U or L is stored in the array AP
as follows:
if UPLO = 'U', AP(i + (j-1)*j/2) = U(i,j) for 1<=i<=j;
if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = L(i,j) for j<=i<=n.

B

B is REAL array, dimension (LDB,NRHS)
On entry, the right hand side matrix B.
On exit, the solution matrix X.

LDB

LDB is INTEGER
The leading dimension of the array B.  LDB >= max(1,N).

INFO

INFO is INTEGER
= 0:  successful exit
< 0:  if INFO = -i, the i-th argument had an illegal value

Author:
Univ. of Tennessee

Univ. of California Berkeley

NAG Ltd.

Date:
November 2011

Definition at line 109 of file spptrs.f.

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

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

## Check Out this Related Man Page

```SPPTRS(l)								 )								 SPPTRS(l)

NAME
SPPTRS  -  solve a system of linear equations A*X = B with a symmetric positive definite matrix A in packed storage using the Cholesky fac-
torization A = U**T*U or A = L*L**T computed by SPPTRF

SYNOPSIS
SUBROUTINE SPPTRS( UPLO, N, NRHS, AP, B, LDB, INFO )

CHARACTER	  UPLO

INTEGER	  INFO, LDB, N, NRHS

REAL 	  AP( * ), B( LDB, * )

PURPOSE
SPPTRS solves a system of linear equations A*X = B with a symmetric positive definite matrix A in packed storage using the Cholesky factor-
ization A = U**T*U or A = L*L**T computed by SPPTRF.

ARGUMENTS
UPLO    (input) CHARACTER*1
= 'U':  Upper triangle of A is stored;
= 'L':  Lower triangle of A is stored.

N       (input) INTEGER
The order of the matrix A.  N >= 0.

NRHS    (input) INTEGER
The number of right hand sides, i.e., the number of columns of the matrix B.  NRHS >= 0.

AP      (input) REAL array, dimension (N*(N+1)/2)
The triangular factor U or L from the Cholesky factorization A = U**T*U or A = L*L**T, packed columnwise in a linear array.  The j-
th column of U or L is stored in the array AP as follows: if UPLO = 'U', AP(i + (j-1)*j/2) = U(i,j) for 1<=i<=j;  if  UPLO  =  'L',
AP(i + (j-1)*(2n-j)/2) = L(i,j) for j<=i<=n.

B       (input/output) REAL array, dimension (LDB,NRHS)
On entry, the right hand side matrix B.	On exit, the solution matrix X.

LDB     (input) INTEGER
The leading dimension of the array B.  LDB >= max(1,N).

INFO    (output) INTEGER
= 0:  successful exit
< 0:  if INFO = -i, the i-th argument had an illegal value

LAPACK version 3.0						   15 June 2000 							 SPPTRS(l)```
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