subroutine ztrtri (UPLO, DIAG, N, A, LDA, INFO)
subroutine ztrtri (characterUPLO, characterDIAG, integerN, complex*16, dimension( lda, * )A, integerLDA, integerINFO)ZTRTRI Purpose:
ZTRTRI computes the inverse of a complex upper or lower triangular matrix A. This is the Level 3 BLAS version of the algorithm.
UPLO is CHARACTER*1 = 'U': A is upper triangular; = 'L': A is lower triangular.DIAG
DIAG is CHARACTER*1 = 'N': A is non-unit triangular; = 'U': A is unit triangular.N
N is INTEGER The order of the matrix A. N >= 0.A
A is COMPLEX*16 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.LDA
LDA is INTEGER The leading dimension of the array A. LDA >= max(1,N).INFO
INFO is INTEGER = 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.
Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd.Date:
November 2011Definition at line 110 of file ztrtri.f.