dtrtri.f File Reference

Go to the source code of this file.

Functions/Subroutines
subroutine	dtrtri (UPLO, DIAG, N, A, LDA, INFO)
	DTRTRI More...

Function/Subroutine Documentation

dtrtri()

subroutine dtrtri	(	character	UPLO,
		character	DIAG,
		integer	N,
		double precision, dimension( lda, * )	A,
		integer	LDA,
		integer	INFO
	)

DTRTRI

Download DTRTRI + dependencies [TGZ] [ZIP] [TXT]

Purpose:

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

 This is the Level 3 BLAS version of the algorithm.

Parameters

[in]	UPLO	UPLO is CHARACTER*1 = 'U': A is upper triangular; = 'L': A is lower triangular.
[in]	DIAG	DIAG is CHARACTER*1 = 'N': A is non-unit triangular; = 'U': A is 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 = -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.

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date

December 2016

Definition at line 110 of file dtrtri.f.

References dtrmm(), dtrsm(), dtrti2(), and xerbla().

Here is the call graph for this function:

Here is the caller graph for this function: