cpptri

NAME

cpptri - compute the inverse of a complex Hermitian positive definite matrix A using the Cholesky factorization A = U**H*U or A = L*L**H computed by CPPTRF

SYNOPSIS

  SUBROUTINE CPPTRI( UPLO, N, A, INFO)
  CHARACTER * 1 UPLO
  COMPLEX A(*)
  INTEGER N, INFO
 
  SUBROUTINE CPPTRI_64( UPLO, N, A, INFO)
  CHARACTER * 1 UPLO
  COMPLEX A(*)
  INTEGER*8 N, INFO

F95 INTERFACE

  SUBROUTINE PPTRI( UPLO, N, A, [INFO])
  CHARACTER(LEN=1) :: UPLO
  COMPLEX, DIMENSION(:) :: A
  INTEGER :: N, INFO
 
  SUBROUTINE PPTRI_64( UPLO, N, A, [INFO])
  CHARACTER(LEN=1) :: UPLO
  COMPLEX, DIMENSION(:) :: A
  INTEGER(8) :: N, INFO

C INTERFACE

#include <sunperf.h>

void cpptri(char uplo, int n, complex *a, int *info);

void cpptri_64(char uplo, long n, complex *a, long *info);

PURPOSE

cpptri computes the inverse of a complex Hermitian positive definite matrix A using the Cholesky factorization A = U**H*U or A = L*L**H computed by CPPTRF.

ARGUMENTS

* UPLO (input)

* N (input)

The order of the matrix A. N >= 0.

* A (input/output)

On entry, the triangular factor U or L from the Cholesky factorization A = U**H*U or A = L*L**H, packed columnwise as a linear array. The j-th column of U or L is stored in the array A as follows: if UPLO = 'U', A(i + (j-1)*j/2) = U(i,j) for 1<=i<=j; if UPLO = 'L', A(i + (j-1)*(2n-j)/2) = L(i,j) for j<=i<=n.

On exit, the upper or lower triangle of the (Hermitian) inverse of A, overwriting the input factor U or L.

* INFO (output)