strtri(3P) Sun Performance Library strtri(3P)NAMEstrtri - 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);
PURPOSEstrtri 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.
6 Mar 2009 strtri(3P)
