spptrs (l)  Linux Man Pages
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
Command to display spptrs
manual in Linux: $ man l spptrs
NAME
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
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
factorization A = U**T*U or A = L*L**T computed by SPPTRF.
ARGUMENTS
 UPLO (input) CHARACTER*1

= aqUaq: Upper triangle of A is stored;
= aqLaq: 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 jth column of U or L is stored in the array AP
as follows:
if UPLO = aqUaq, AP(i + (j1)*j/2) = U(i,j) for 1<=i<=j;
if UPLO = aqLaq, AP(i + (j1)*(2nj)/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 ith argument had an illegal value
Pages related to spptrs
 spptrs (3)
 spptrf (l)  computes the Cholesky factorization of a real symmetric positive definite matrix A stored in packed format
 spptri (l)  computes the inverse of a real symmetric positive definite matrix A using the Cholesky factorization A = U**T*U or A = L*L**T computed by SPPTRF
 sppcon (l)  estimates the reciprocal of the condition number (in the 1norm) of a real symmetric positive definite packed matrix using the Cholesky factorization A = U**T*U or A = L*L**T computed by SPPTRF
 sppequ (l)  computes row and column scalings intended to equilibrate a symmetric positive definite matrix A in packed storage and reduce its condition number (with respect to the twonorm)
 spprfs (l)  improves the computed solution to a system of linear equations when the coefficient matrix is symmetric positive definite and packed, and provides error bounds and backward error estimates for the solution
 sppsv (l)  computes the solution to a real system of linear equations A * X = B,
 sppsvx (l)  uses the Cholesky factorization A = U**T*U or A = L*L**T to compute the solution to a real system of linear equations A * X = B,