SPODI(3F)

NAME
     SPODI   - SPODI computes the determinant and inverse of a certain real
     symmetric positive definite matrix (see below) using the factors computed
     by SPOCO, SPOFA or SQRDC.


SYNOPSYS
      SUBROUTINE SPODI(A,LDA,N,DET,JOB)

DESCRIPTION
     On Entry

     A REAL(LDA, N)
        the output  A  from SPOCO or SPOFA
        or the output  X  from SQRDC.

     LDA INTEGER
        the leading dimension of the array  A .

     N INTEGER
        the order of the matrix  A .

     JOB INTEGER
        = 11   both determinant and inverse.
        = 01   inverse only.
        = 10   determinant only.  On Return

     A If SPOCO or SPOFA was used to factor  A , then
        SPODI produces the upper half of INVERSE(A) .
        If SQRDC was used to decompose  X , then
        SPODI produces the upper half of INVERSE(TRANS(X)*X),
        where TRANS(X) is the transpose.
        Elements of  A  below the diagonal are unchanged.
        If the units digit of JOB is zero,  A  is unchanged.

     DET REAL(2)
        determinant of  A  or of  TRANS(X)*X  if requested.
        Otherwise not referenced.
        Determinant = DET(1) * 10.0**DET(2)
        with  1.0 .LE. DET(1) .LT. 10.0
        or  DET(1) .EQ. 0.0 .  Error Condition

     A division by zero will occur if the input factor contains a zero on the
     diagonal and the inverse is requested.  It will not occur if the
     subroutines are called correctly and if SPOCO or SPOFA has set INFO .EQ.
     0 .  LINPACK.  This version dated 08/14/78 .  Cleve Moler, University of
     New Mexico, Argonne National Lab.  Subroutines and Functions BLAS
     SAXPY,SSCAL Fortran MOD