dpofa

NAME

dpofa - (obsolete) compute a Cholesky factorization of a symmetric positive definite matrix A. It is typical to follow a call to SPOFA with a call to SPOSL to solve Ax = b or to SPODI to compute the determinant and inverse of A.

SYNOPSIS

  SUBROUTINE DPOFA( A, LDA, N, INFO)
  INTEGER LDA, N, INFO
  DOUBLE PRECISION A(LDA,*)
 
  SUBROUTINE DPOFA_64( A, LDA, N, INFO)
  INTEGER*8 LDA, N, INFO
  DOUBLE PRECISION A(LDA,*)

C INTERFACE

#include <sunperf.h>

void dpofa(double *a, int lda, int n, int *info);

void dpofa_64(double *a, long lda, 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. The strict lower triangle of A is not referenced.

* LDA (input)

Leading dimension of the array A as specified in a dimension or type statement. LDA >= max(1,N).

* 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 the leading minor of order k is not positive definite.