dpttrs (3p)

Name

dpttrs - solve a tridiagonal system of the form A * X = B using the L*D*L' factorization of A computed by DPTTRF

Synopsis

SUBROUTINE DPTTRS(N, NRHS, D, E, B, LDB, INFO)

INTEGER N, NRHS, LDB, INFO
DOUBLE PRECISION D(*), E(*), B(LDB,*)

SUBROUTINE DPTTRS_64(N, NRHS, D, E, B, LDB, INFO)

INTEGER*8 N, NRHS, LDB, INFO
DOUBLE PRECISION D(*), E(*), B(LDB,*)




F95 INTERFACE
SUBROUTINE PTTRS(N, NRHS, D, E, B, LDB, INFO)

INTEGER :: N, NRHS, LDB, INFO
REAL(8), DIMENSION(:) :: D, E
REAL(8), DIMENSION(:,:) :: B

SUBROUTINE PTTRS_64(N, NRHS, D, E, B, LDB, INFO)

INTEGER(8) :: N, NRHS, LDB, INFO
REAL(8), DIMENSION(:) :: D, E
REAL(8), DIMENSION(:,:) :: B




C INTERFACE
#include <sunperf.h>

void dpttrs(int n, int nrhs, double *d, double *e, double *b, int  ldb,
int *info);

void dpttrs_64(long n, long nrhs, double *d, double *e, double *b, long
ldb, long *info);

Description

Oracle Solaris Studio Performance Library                           dpttrs(3P)



NAME
       dpttrs  -  solve  a tridiagonal system of the form  A * X = B using the
       L*D*L' factorization of A computed by DPTTRF


SYNOPSIS
       SUBROUTINE DPTTRS(N, NRHS, D, E, B, LDB, INFO)

       INTEGER N, NRHS, LDB, INFO
       DOUBLE PRECISION D(*), E(*), B(LDB,*)

       SUBROUTINE DPTTRS_64(N, NRHS, D, E, B, LDB, INFO)

       INTEGER*8 N, NRHS, LDB, INFO
       DOUBLE PRECISION D(*), E(*), B(LDB,*)




   F95 INTERFACE
       SUBROUTINE PTTRS(N, NRHS, D, E, B, LDB, INFO)

       INTEGER :: N, NRHS, LDB, INFO
       REAL(8), DIMENSION(:) :: D, E
       REAL(8), DIMENSION(:,:) :: B

       SUBROUTINE PTTRS_64(N, NRHS, D, E, B, LDB, INFO)

       INTEGER(8) :: N, NRHS, LDB, INFO
       REAL(8), DIMENSION(:) :: D, E
       REAL(8), DIMENSION(:,:) :: B




   C INTERFACE
       #include <sunperf.h>

       void dpttrs(int n, int nrhs, double *d, double *e, double *b, int  ldb,
                 int *info);

       void dpttrs_64(long n, long nrhs, double *d, double *e, double *b, long
                 ldb, long *info);



PURPOSE
       dpttrs solves a tridiagonal system of the form
          A * X = B using the L*D*L' factorization of A computed by DPTTRF.  D
       is  a diagonal matrix specified in the vector D, L is a unit bidiagonal
       matrix whose subdiagonal is specified in the vector E, and X and B  are
       N by NRHS matrices.


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


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


       D (input) The n diagonal elements of the diagonal  matrix  D  from  the
                 L*D*L' factorization of A.


       E (input) The  (n-1) subdiagonal elements of the unit bidiagonal factor
                 L from the L*D*L' factorization of A.  E can also be regarded
                 as the superdiagonal of the unit bidiagonal factor U from the
                 factorization A = U'*D*U.


       B (input/output)
                 On entry, the right hand side vectors B  for  the  system  of
                 linear equations.  On exit, the solution vectors, X.


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


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




                                  7 Nov 2015                        dpttrs(3P)