[ новости /+++ | форум | теги | ]

NAME
     zpptri - 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 ZPPTRF

SYNOPSIS
     SUBROUTINE ZPPTRI( UPLO, N, AP, INFO )

     CHARACTER UPLO

     INTEGER INFO, N

     COMPLEX*16 AP( * )



     #include <sunperf.h>

     void  zpptri(char  uplo,  int  n,  doublecomplex  *zap,  int
               *info);

PURPOSE
     ZPPTRI 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 ZPPTRF.


ARGUMENTS
     UPLO      (input) CHARACTER*1
               = 'U':  Upper triangular factor is stored in AP;
               = 'L':  Lower triangular factor is stored in AP.

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

     AP        (input/output)   COMPLEX*16    array,    dimension
               (N*(N+1)/2)
               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 AP as fol-
               lows:  if UPLO = 'U', AP(i + (j-1)*j/2)  =  U(i,j)
               for 1<=i<=j; if UPLO = 'L', AP(i + (j-1)*(2n-j)/2)
               = L(i,j) for j<=i<=n.

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

     INFO      (output) INTEGER
               = 0:  successful exit
               < 0:  if INFO =  -i,  the  i-th  argument  had  an
               illegal value
               > 0:  if INFO = i, the (i,i) element of the factor
               U  or L is zero, and the inverse could not be com-
               puted.

Партнёры:

Хостинг: