Contents
strti2 - compute the inverse of a real upper or lower tri-
angular matrix
SUBROUTINE STRTI2(UPLO, DIAG, N, A, LDA, INFO)
CHARACTER * 1 UPLO, DIAG
INTEGER N, LDA, INFO
REAL A(LDA,*)
SUBROUTINE STRTI2_64(UPLO, DIAG, N, A, LDA, INFO)
CHARACTER * 1 UPLO, DIAG
INTEGER*8 N, LDA, INFO
REAL A(LDA,*)
F95 INTERFACE
SUBROUTINE TRTI2(UPLO, DIAG, [N], A, [LDA], [INFO])
CHARACTER(LEN=1) :: UPLO, DIAG
INTEGER :: N, LDA, INFO
REAL, DIMENSION(:,:) :: A
SUBROUTINE TRTI2_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 strti2(char uplo, char diag, int n, float *a, int lda,
int *info);
void strti2_64(char uplo, char diag, long n, float *a, long
lda, long *info);
strti2 computes the inverse of a real upper or lower tri-
angular matrix.
This is the Level 2 BLAS version of the algorithm.
UPLO (input)
Specifies whether the matrix A is upper or lower
triangular. = 'U': Upper triangular
= 'L': Lower triangular
DIAG (input)
Specifies whether or not the matrix A is unit tri-
angular. = 'N': Non-unit triangular
= 'U': 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 leading 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 = -k, the k-th argument had an ille-
gal value