DPOFA(3F)

NAME
     DPOFA   - DPOFA factors a double precision symmetric positive definite
     matrix.

     DPOFA is usually called by DPOCO, but it can be called directly with a
     saving in time if  RCOND  is not needed.  (time for DPOCO) = (1 +
     18/N)*(time for DPOFA) .


SYNOPSYS
      SUBROUTINE DPOFA(A,LDA,N,INFO)

DESCRIPTION
     On Entry

     A DOUBLE PRECISION(LDA, N)
        the symmetric matrix to be factored.  Only the
        diagonal and upper triangle are used.

     LDA INTEGER
        the leading dimension of the array  A .

     N INTEGER
        the order of the matrix  A .  On Return

     A an upper triangular matrix  R  so that  A = TRANS(R)*R
        where  TRANS(R)  is the transpose.
        The strict lower triangle is unaltered.
        If  INFO .NE. 0 , the factorization is not complete.

     INFO INTEGER
        = 0  for normal return.
        = K  signals an error condition.  The leading minor
        of order  K  is not positive definite.  LINPACK.  This version dated
     08/14/78 .  Cleve Moler, University of New Mexico, Argonne National Lab.
     Subroutines and Functions BLAS DDOT Fortran DSQRT