stptri

NAME

stptri - compute the inverse of a real upper or lower triangular matrix A stored in packed format

SYNOPSIS 

  SUBROUTINE STPTRI( UPLO, DIAG, N, A, INFO)
  CHARACTER * 1 UPLO, DIAG
  INTEGER N, INFO
  REAL A(*)
 
  SUBROUTINE STPTRI_64( UPLO, DIAG, N, A, INFO)
  CHARACTER * 1 UPLO, DIAG
  INTEGER*8 N, INFO
  REAL A(*)

F95 INTERFACE 

  SUBROUTINE TPTRI( UPLO, DIAG, N, A, [INFO])
  CHARACTER(LEN=1) :: UPLO, DIAG
  INTEGER :: N, INFO
  REAL, DIMENSION(:) :: A
 
  SUBROUTINE TPTRI_64( UPLO, DIAG, N, A, [INFO])
  CHARACTER(LEN=1) :: UPLO, DIAG
  INTEGER(8) :: N, INFO
  REAL, DIMENSION(:) :: A

C INTERFACE

#include <sunperf.h>

void stptri(char uplo, char diag, int n, float *a, int *info);

void stptri_64(char uplo, char diag, long n, float *a, long *info);

PURPOSE

stptri computes the inverse of a real upper or lower triangular matrix A stored in packed format.

ARGUMENTS

* UPLO (input)
* DIAG (input)

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

* A (input/output)
On entry, the upper or lower triangular matrix A, stored columnwise in a linear array. The j-th column of A is stored in the array A as follows: if UPLO = 'U', A(i + (j-1)*j/2) = A(i,j) for 1<=i<=j; if UPLO = 'L', A(i + (j-1)*((2*n-j)/2) = A(i,j) for j<=i<=n. See below for further details. On exit, the (triangular) inverse of the original matrix, in the same packed storage format.

* INFO (output)