dtrti2.f man page

dtrti2.f —

Synopsis

Functions/Subroutines

subroutine dtrti2 (UPLO, DIAG, N, A, LDA, INFO)
DTRTI2 computes the inverse of a triangular matrix (unblocked algorithm).

Function/Subroutine Documentation

subroutine dtrti2 (characterUPLO, characterDIAG, integerN, double precision, dimension( lda, * )A, integerLDA, integerINFO)

DTRTI2 computes the inverse of a triangular matrix (unblocked algorithm).

Purpose:

DTRTI2 computes the inverse of a real upper or lower triangular
matrix.

This is the Level 2 BLAS version of the algorithm.

Parameters:

UPLO

UPLO is CHARACTER*1
Specifies whether the matrix A is upper or lower triangular.
= 'U':  Upper triangular
= 'L':  Lower triangular

DIAG

DIAG is CHARACTER*1
Specifies whether or not the matrix A is unit triangular.
= 'N':  Non-unit triangular
= 'U':  Unit triangular

N

N is INTEGER
The order of the matrix A.  N >= 0.

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.

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 = -k, the k-th argument had an illegal value

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

September 2012

Definition at line 111 of file dtrti2.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

dtrti2(3) is an alias of dtrti2.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK