ctrti2


NAME

ctrti2 - compute the inverse of a complex upper or lower triangular matrix


SYNOPSIS

  SUBROUTINE CTRTI2( UPLO, DIAG, N, A, LDA, INFO)
  CHARACTER * 1 UPLO, DIAG
  COMPLEX A(LDA,*)
  INTEGER N, LDA, INFO
 
  SUBROUTINE CTRTI2_64( UPLO, DIAG, N, A, LDA, INFO)
  CHARACTER * 1 UPLO, DIAG
  COMPLEX A(LDA,*)
  INTEGER*8 N, LDA, INFO
 

F95 INTERFACE

  SUBROUTINE TRTI2( UPLO, DIAG, [N], A, [LDA], [INFO])
  CHARACTER(LEN=1) :: UPLO, DIAG
  COMPLEX, DIMENSION(:,:) :: A
  INTEGER :: N, LDA, INFO
 
  SUBROUTINE TRTI2_64( UPLO, DIAG, [N], A, [LDA], [INFO])
  CHARACTER(LEN=1) :: UPLO, DIAG
  COMPLEX, DIMENSION(:,:) :: A
  INTEGER(8) :: N, LDA, INFO
 

C INTERFACE

#include <sunperf.h>

void ctrti2(char uplo, char diag, int n, complex *a, int lda, int *info);

void ctrti2_64(char uplo, char diag, long n, complex *a, long lda, long *info);


PURPOSE

ctrti2 computes the inverse of a complex upper or lower triangular matrix.

This is the Level 2 BLAS version of the algorithm.


ARGUMENTS

* UPLO (input)
Specifies whether the matrix A is upper or lower triangular.

* DIAG (input)
Specifies whether or not the matrix A is unit triangular.

* N (input)
The order of the matrix A. N >= 0.

* A (input/output)
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 (input)
The leading dimension of the array A. LDA >= max(1,N).

* INFO (output)