ztrti2 (l) - Linux Manuals

ztrti2: computes the inverse of a complex upper or lower triangular matrix

NAME

ZTRTI2 - computes the inverse of a complex upper or lower triangular matrix

SYNOPSIS

SUBROUTINE ZTRTI2(
UPLO, DIAG, N, A, LDA, INFO )

    
CHARACTER DIAG, UPLO

    
INTEGER INFO, LDA, N

    
COMPLEX*16 A( LDA, * )

PURPOSE

ZTRTI2 computes the inverse of a complex upper or lower triangular matrix. This is the Level 2 BLAS version of the algorithm.

ARGUMENTS

UPLO (input) CHARACTER*1
Specifies whether the matrix A is upper or lower triangular. = aqUaq: Upper triangular
= aqLaq: Lower triangular
DIAG (input) CHARACTER*1
Specifies whether or not the matrix A is unit triangular. = aqNaq: Non-unit triangular
= aqUaq: Unit triangular
N (input) INTEGER
The order of the matrix A. N >= 0.
A (input/output) COMPLEX*16 array, dimension (LDA,N)
On entry, the triangular matrix A. If UPLO = aqUaq, 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 = aqLaq, 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 = aqUaq, 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) INTEGER
The leading dimension of the array A. LDA >= max(1,N).
INFO (output) INTEGER
= 0: successful exit
< 0: if INFO = -k, the k-th argument had an illegal value

Pages related to ztrti2

  • ztrti2 (3)
  • ztrtri (l) - computes the inverse of a complex upper or lower triangular matrix A
  • ztrtrs (l) - solves a triangular system of the form A * X = B, A**T * X = B, or A**H * X = B,
  • ztrttf (l) - copies a triangular matrix A from standard full format (TR) to rectangular full packed format (TF)
  • ztrttp (l) - copies a triangular matrix A from full format (TR) to standard packed format (TP)
  • ztrcon (l) - estimates the reciprocal of the condition number of a triangular matrix A, in either the 1-norm or the infinity-norm
  • ztrevc (l) - computes some or all of the right and/or left eigenvectors of a complex upper triangular matrix T
  • ztrexc (l) - reorders the Schur factorization of a complex matrix A = Q*T*Q**H, so that the diagonal element of T with row index IFST is moved to row ILST