NAME

SYNOPSIS

  SUBROUTINE DTRTI2( UPLO, DIAG, N, A, LDA, INFO)
  CHARACTER * 1 UPLO, DIAG
  INTEGER N, LDA, INFO
  DOUBLE PRECISION A(LDA,*)
 
  SUBROUTINE DTRTI2_64( UPLO, DIAG, N, A, LDA, INFO)
  CHARACTER * 1 UPLO, DIAG
  INTEGER*8 N, LDA, INFO
  DOUBLE PRECISION A(LDA,*)
 

F95 INTERFACE

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

C INTERFACE

void dtrti2(char uplo, char diag, int n, double *a, int lda, int *info);

void dtrti2_64(char uplo, char diag, long n, double *a, long lda, long *info);

PURPOSE

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)