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LAPACK
3.7.0
LAPACK: Linear Algebra PACKage
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subroutine dtrti2 | ( | character | UPLO, |
character | DIAG, | ||
integer | N, | ||
double precision, dimension( lda, * ) | A, | ||
integer | LDA, | ||
integer | INFO | ||
) |
DTRTI2 computes the inverse of a triangular matrix (unblocked algorithm).
Download DTRTI2 + dependencies [TGZ] [ZIP] [TXT]
DTRTI2 computes the inverse of a real upper or lower triangular matrix. This is the Level 2 BLAS version of the algorithm.
[in] | UPLO | UPLO is CHARACTER*1 Specifies whether the matrix A is upper or lower triangular. = 'U': Upper triangular = 'L': Lower triangular |
[in] | DIAG | DIAG is CHARACTER*1 Specifies whether or not the matrix A is unit triangular. = 'N': Non-unit triangular = 'U': Unit triangular |
[in] | N | N is INTEGER The order of the matrix A. N >= 0. |
[in,out] | A | A is DOUBLE PRECISION array, dimension (LDA,N) 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. |
[in] | LDA | LDA is INTEGER The leading dimension of the array A. LDA >= max(1,N). |
[out] | INFO | INFO is INTEGER = 0: successful exit < 0: if INFO = -k, the k-th argument had an illegal value |
Definition at line 112 of file dtrti2.f.