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Updated: June 2017
 
 

dpptrs (3p)

Name

dpptrs - solve 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 DPPTRF

Synopsis

SUBROUTINE DPPTRS(UPLO, N, NRHS, A, B, LDB, INFO)

CHARACTER*1 UPLO
INTEGER N, NRHS, LDB, INFO
DOUBLE PRECISION A(*), B(LDB,*)

SUBROUTINE DPPTRS_64(UPLO, N, NRHS, A, B, LDB, INFO)

CHARACTER*1 UPLO
INTEGER*8 N, NRHS, LDB, INFO
DOUBLE PRECISION A(*), B(LDB,*)




F95 INTERFACE
SUBROUTINE PPTRS(UPLO, N, NRHS, A, B, LDB, INFO)

CHARACTER(LEN=1) :: UPLO
INTEGER :: N, NRHS, LDB, INFO
REAL(8), DIMENSION(:) :: A
REAL(8), DIMENSION(:,:) :: B

SUBROUTINE PPTRS_64(UPLO, N, NRHS, A, B, LDB, INFO)

CHARACTER(LEN=1) :: UPLO
INTEGER(8) :: N, NRHS, LDB, INFO
REAL(8), DIMENSION(:) :: A
REAL(8), DIMENSION(:,:) :: B




C INTERFACE
#include <sunperf.h>

void  dpptrs(char uplo, int n, int nrhs, double *a, double *b, int ldb,
int *info);

void dpptrs_64(char uplo, long n, long nrhs, double *a, double *b, long
ldb, long *info);

Description

Oracle Solaris Studio Performance Library                           dpptrs(3P)



NAME
       dpptrs  -  solve  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 DPPTRF


SYNOPSIS
       SUBROUTINE DPPTRS(UPLO, N, NRHS, A, B, LDB, INFO)

       CHARACTER*1 UPLO
       INTEGER N, NRHS, LDB, INFO
       DOUBLE PRECISION A(*), B(LDB,*)

       SUBROUTINE DPPTRS_64(UPLO, N, NRHS, A, B, LDB, INFO)

       CHARACTER*1 UPLO
       INTEGER*8 N, NRHS, LDB, INFO
       DOUBLE PRECISION A(*), B(LDB,*)




   F95 INTERFACE
       SUBROUTINE PPTRS(UPLO, N, NRHS, A, B, LDB, INFO)

       CHARACTER(LEN=1) :: UPLO
       INTEGER :: N, NRHS, LDB, INFO
       REAL(8), DIMENSION(:) :: A
       REAL(8), DIMENSION(:,:) :: B

       SUBROUTINE PPTRS_64(UPLO, N, NRHS, A, B, LDB, INFO)

       CHARACTER(LEN=1) :: UPLO
       INTEGER(8) :: N, NRHS, LDB, INFO
       REAL(8), DIMENSION(:) :: A
       REAL(8), DIMENSION(:,:) :: B




   C INTERFACE
       #include <sunperf.h>

       void  dpptrs(char uplo, int n, int nrhs, double *a, double *b, int ldb,
                 int *info);

       void dpptrs_64(char uplo, long n, long nrhs, double *a, double *b, long
                 ldb, long *info);



PURPOSE
       dpptrs  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 DPPTRF.


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


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


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


       A (input) DOUBLE PRECISION 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 A as
                 follows:  if  UPLO  =  'U',  A(i  +  (j-1)*j/2)  = U(i,j) for
                 1<=i<=j; if UPLO = 'L', A(i + (j-1)*(2n-j)/2)  =  L(i,j)  for
                 j<=i<=n.


       B (input/output) DOUBLE PRECISION array, dimension (LDB,NRHS)
                 On  entry,  the right hand side matrix B.  On exit, the solu-
                 tion matrix X.


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


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




                                  7 Nov 2015                        dpptrs(3P)