zppfa


NAME

zppfa - (obsolete) compute a Cholesky factorization of a symmetric positive definite matrix A in packed storage. It is typical to follow a call to CPPFA with a call to CPPSL to solve Ax = b or to CPPDI to compute the determinant and inverse of A.


SYNOPSIS

  SUBROUTINE ZPPFA( A, N, INFO)
  DOUBLE COMPLEX A(*)
  INTEGER N, INFO
 
  SUBROUTINE ZPPFA_64( A, N, INFO)
  DOUBLE COMPLEX A(*)
  INTEGER*8 N, INFO
 

C INTERFACE

#include <sunperf.h>

void zppfa(doublecomplex *a, int n, int *info);

void zppfa_64(doublecomplex *a, long n, long *info);


ARGUMENTS

* A (input/output)
On entry, the upper triangle of the matrix A. On exit, a Cholesky factorization of the matrix A.

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

* INFO (output)
On exit:

INFO = 0 Subroutine completed normally.

INFO > 0 Returns a value k if U(k,k) = 0 to indicate that CPPSL will divide by zero if called.