ztbcon ztbtrs ztpcon ztptri ztptrs ztrcon ztrtri ztrtrs

ztrtri() void ztrtri ( char  uplo, char  diag, int  n, int  lda, doublecomplex  a[], int *  info  ) Inverse of a complex triangular matrix Purpose This routine computes the inverse of a complex upper or lower triangular matrix A. This is the Level 3 BLAS version of the algorithm. Parameters [in] uplo = 'U': A is upper triangular. = 'L': A is lower triangular. [in] diag = 'N': A is non-unit triangular. = 'U': A is unit triangular. (Diagonal elements of a[][] are not referenced and are assumed to be 1) [in] n Order of the matrix A. (n >= 0) (If n = 0, returns without computation) [in] lda Leading dimension of the two dimensional array a[][]. (lda >= max(1, n)) [in,out] a[][] Array a[la][lda] (la >= n) [in] n x n triangular matrix A. Only the upper or lower triangular part is to be referenced in accordance with uplo. [out] The (triangular) inverse of the original matrix. [out] info = 0: Successful exit = -1: The argument uplo had an illegal value (uplo != 'U' nor 'L') = -2: The argument diag had an illegal value (diag != 'N' nor 'U') = -3: The argument n had an illegal value (n < 0) = -4: The argument lda had an illegal value (lda < max(1, n)) = i > 0: The i-th diagonal element of A is exactly zero. The triangular matrix is singular and its inverse can not be computed. Reference LAPACK