dptsv (3p)

Name

dptsv - compute the solution to a real system of linear equations A*X = B, where A is an N-by-N symmetric positive definite tridiagonal matrix, and X and B are N-by-NRHS matrices

Synopsis

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

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

SUBROUTINE DPTSV_64(N, NRHS, D, E, B, LDB, INFO)

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




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

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

SUBROUTINE PTSV_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  dptsv(int  n, int nrhs, double *d, double *e, double *b, int ldb,
int *info);

void dptsv_64(long n, long nrhs, double *d, double *e, double *b,  long
ldb, long *info);

Description

Oracle Solaris Studio Performance Library                            dptsv(3P)



NAME
       dptsv - compute the solution to a real system of linear equations A*X =
       B, where A is an N-by-N symmetric positive definite tridiagonal matrix,
       and X and B are N-by-NRHS matrices


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

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

       SUBROUTINE DPTSV_64(N, NRHS, D, E, B, LDB, INFO)

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




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

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

       SUBROUTINE PTSV_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  dptsv(int  n, int nrhs, double *d, double *e, double *b, int ldb,
                 int *info);

       void dptsv_64(long n, long nrhs, double *d, double *e, double *b,  long
                 ldb, long *info);



PURPOSE
       dptsv  computes the solution to a real system of linear equations A*X =
       B, where A is an N-by-N symmetric positive definite tridiagonal matrix,
       and X and B are N-by-NRHS matrices.

       A  is factored as A = L*D*L**T, and the factored form of A is then used
       to solve the system of equations.


ARGUMENTS
       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.


       D (input/output)
                 On  entry,  the n diagonal elements of the tridiagonal matrix
                 A.  On exit, the n diagonal elements of the diagonal matrix D
                 from the factorization A = L*D*L**T.


       E (input/output)
                 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.)


       B (input/output)
                 On  entry,  the N-by-NRHS right hand side matrix B.  On exit,
                 if INFO = 0, the N-by-NRHS solution 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
                 > 0:  if INFO = i, the leading minor of order i is not  posi-
                 tive  definite,  and the solution has not been computed.  The
                 factorization has not been completed unless i = N.




                                  7 Nov 2015                         dptsv(3P)