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Updated: June 2017
 
 

strtri (3p)

Name

strtri - compute the inverse of a real upper or lower triangular matrix A

Synopsis

SUBROUTINE STRTRI(UPLO, DIAG, N, A, LDA, INFO)

CHARACTER*1 UPLO, DIAG
INTEGER N, LDA, INFO
REAL A(LDA,*)

SUBROUTINE STRTRI_64(UPLO, DIAG, N, A, LDA, INFO)

CHARACTER*1 UPLO, DIAG
INTEGER*8 N, LDA, INFO
REAL A(LDA,*)




F95 INTERFACE
SUBROUTINE TRTRI(UPLO, DIAG, N, A, LDA, INFO)

CHARACTER(LEN=1) :: UPLO, DIAG
INTEGER :: N, LDA, INFO
REAL, DIMENSION(:,:) :: A

SUBROUTINE TRTRI_64(UPLO, DIAG, N, A, LDA, INFO)

CHARACTER(LEN=1) :: UPLO, DIAG
INTEGER(8) :: N, LDA, INFO
REAL, DIMENSION(:,:) :: A




C INTERFACE
#include <sunperf.h>

void strtri(char uplo, char diag, int n, float *a, int lda, int *info);

void  strtri_64(char  uplo, char diag, long n, float *a, long lda, long
*info);

Description

Oracle Solaris Studio Performance Library                           strtri(3P)



NAME
       strtri - compute the inverse of a real upper or lower triangular matrix
       A


SYNOPSIS
       SUBROUTINE STRTRI(UPLO, DIAG, N, A, LDA, INFO)

       CHARACTER*1 UPLO, DIAG
       INTEGER N, LDA, INFO
       REAL A(LDA,*)

       SUBROUTINE STRTRI_64(UPLO, DIAG, N, A, LDA, INFO)

       CHARACTER*1 UPLO, DIAG
       INTEGER*8 N, LDA, INFO
       REAL A(LDA,*)




   F95 INTERFACE
       SUBROUTINE TRTRI(UPLO, DIAG, N, A, LDA, INFO)

       CHARACTER(LEN=1) :: UPLO, DIAG
       INTEGER :: N, LDA, INFO
       REAL, DIMENSION(:,:) :: A

       SUBROUTINE TRTRI_64(UPLO, DIAG, N, A, LDA, INFO)

       CHARACTER(LEN=1) :: UPLO, DIAG
       INTEGER(8) :: N, LDA, INFO
       REAL, DIMENSION(:,:) :: A




   C INTERFACE
       #include <sunperf.h>

       void strtri(char uplo, char diag, int n, float *a, int lda, int *info);

       void  strtri_64(char  uplo, char diag, long n, float *a, long lda, long
                 *info);



PURPOSE
       strtri computes the inverse of a real upper or lower triangular  matrix
       A.

       This is the Level 3 BLAS version of the algorithm.


ARGUMENTS
       UPLO (input)
                 = 'U':  A is upper triangular;
                 = 'L':  A is lower triangular.


       DIAG (input)
                 = 'N':  A is non-unit triangular;
                 = 'U':  A is unit triangular.


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


       A (input/output)
                 On  entry, the triangular matrix A.  If UPLO = 'U', the lead-
                 ing N-by-N upper triangular part of the array A contains  the
                 upper  triangular  matrix,  and the strictly lower triangular
                 part of A is not referenced.  If UPLO = 'L', the  leading  N-
                 by-N  lower triangular part of the array A contains the lower
                 triangular matrix, and the strictly upper triangular part  of
                 A is not referenced.  If DIAG = 'U', the diagonal elements of
                 A are also not referenced and are assumed to be 1.  On  exit,
                 the  (triangular) inverse of the original matrix, in the same
                 storage format.


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


       INFO (output)
                 = 0: successful exit
                 < 0: if INFO = -i, the i-th argument had an illegal value
                 > 0: if INFO = i, A(i,i) is  exactly  zero.   The  triangular
                 matrix is singular and its inverse can not be computed.




                                  7 Nov 2015                        strtri(3P)