dsptri (3p)

Name

dsptri - compute the inverse of a real symmetric indefinite matrix A in packed storage using the factorization A = U*D*U**T or A = L*D*L**T computed by DSPTRF

Synopsis

SUBROUTINE DSPTRI(UPLO, N, AP, IPIVOT, WORK, INFO)

CHARACTER*1 UPLO
INTEGER N, INFO
INTEGER IPIVOT(*)
DOUBLE PRECISION AP(*), WORK(*)

SUBROUTINE DSPTRI_64(UPLO, N, AP, IPIVOT, WORK, INFO)

CHARACTER*1 UPLO
INTEGER*8 N, INFO
INTEGER*8 IPIVOT(*)
DOUBLE PRECISION AP(*), WORK(*)




F95 INTERFACE
SUBROUTINE SPTRI(UPLO, N, AP, IPIVOT, WORK, INFO)

CHARACTER(LEN=1) :: UPLO
INTEGER :: N, INFO
INTEGER, DIMENSION(:) :: IPIVOT
REAL(8), DIMENSION(:) :: AP, WORK

SUBROUTINE SPTRI_64(UPLO, N, AP, IPIVOT, WORK, INFO)

CHARACTER(LEN=1) :: UPLO
INTEGER(8) :: N, INFO
INTEGER(8), DIMENSION(:) :: IPIVOT
REAL(8), DIMENSION(:) :: AP, WORK




C INTERFACE
#include <sunperf.h>

void dsptri(char uplo, int n, double *a, int *ipivot, int *info);

void dsptri_64(char uplo, long n, double *a, long *ipivot, long *info);

Description

Oracle Solaris Studio Performance Library                           dsptri(3P)



NAME
       dsptri - compute the inverse of a real symmetric indefinite matrix A in
       packed storage using the factorization A = U*D*U**T  or  A  =  L*D*L**T
       computed by DSPTRF


SYNOPSIS
       SUBROUTINE DSPTRI(UPLO, N, AP, IPIVOT, WORK, INFO)

       CHARACTER*1 UPLO
       INTEGER N, INFO
       INTEGER IPIVOT(*)
       DOUBLE PRECISION AP(*), WORK(*)

       SUBROUTINE DSPTRI_64(UPLO, N, AP, IPIVOT, WORK, INFO)

       CHARACTER*1 UPLO
       INTEGER*8 N, INFO
       INTEGER*8 IPIVOT(*)
       DOUBLE PRECISION AP(*), WORK(*)




   F95 INTERFACE
       SUBROUTINE SPTRI(UPLO, N, AP, IPIVOT, WORK, INFO)

       CHARACTER(LEN=1) :: UPLO
       INTEGER :: N, INFO
       INTEGER, DIMENSION(:) :: IPIVOT
       REAL(8), DIMENSION(:) :: AP, WORK

       SUBROUTINE SPTRI_64(UPLO, N, AP, IPIVOT, WORK, INFO)

       CHARACTER(LEN=1) :: UPLO
       INTEGER(8) :: N, INFO
       INTEGER(8), DIMENSION(:) :: IPIVOT
       REAL(8), DIMENSION(:) :: AP, WORK




   C INTERFACE
       #include <sunperf.h>

       void dsptri(char uplo, int n, double *a, int *ipivot, int *info);

       void dsptri_64(char uplo, long n, double *a, long *ipivot, long *info);



PURPOSE
       dsptri computes the inverse of a real symmetric indefinite matrix A  in
       packed  storage  using  the  factorization A = U*D*U**T or A = L*D*L**T
       computed by DSPTRF.


ARGUMENTS
       UPLO (input)
                 Specifies whether the details of the factorization are stored
                 as an upper or lower triangular matrix.  = 'U':  Upper trian-
                 gular, form is A = U*D*U**T;
                 = 'L':  Lower triangular, form is A = L*D*L**T.


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


       AP (input/output)
                 Double precision array, dimension (N*(N+1)/2) On  entry,  the
                 block  diagonal  matrix  D and the multipliers used to obtain
                 the factor U or L as computed by DSPTRF, stored as  a  packed
                 triangular matrix.

                 On exit, if INFO = 0, the (symmetric) inverse of the original
                 matrix, stored as a packed triangular matrix. The j-th column
                 of  inv(A)  is  stored  in the array AP as follows: if UPLO =
                 'U', AP(i + (j-1)*j/2) = inv(A)(i,j) for 1<=i<=j; if  UPLO  =
                 'L', AP(i + (j-1)*(2n-j)/2) = inv(A)(i,j) for j<=i<=n.


       IPIVOT (input)
                 Integer  array, dimension (N) Details of the interchanges and
                 the block structure of D as determined by DSPTRF.


       WORK (workspace)
                 Double precision array, dimension(N)

       INFO (output)
                 = 0: successful exit
                 < 0: if INFO = -i, the i-th argument had an illegal value
                 > 0: if INFO = i, D(i,i) = 0; the matrix is singular and  its
                 inverse could not be computed.




                                  7 Nov 2015                        dsptri(3P)