# ctrtri.f - Man Page

SRC/ctrtri.f

## Synopsis

### Functions/Subroutines

subroutine ctrtri (uplo, diag, n, a, lda, info)
CTRTRI

## Function/Subroutine Documentation

### subroutine ctrtri (character uplo, character diag, integer n, complex, dimension( lda, * ) a, integer lda, integer info)

CTRTRI

Purpose:

``` CTRTRI computes the inverse of a complex upper or lower triangular
matrix A.

This is the Level 3 BLAS version of the algorithm.```
Parameters

UPLO

```          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 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.```
Author

Univ. of Tennessee

Univ. of California Berkeley

NAG Ltd.

Definition at line 108 of file ctrtri.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page ctrtri(3) is an alias of ctrtri.f(3).

Tue Nov 28 2023 12:08:41 Version 3.12.0 LAPACK