 
      SUBROUTINE SPODI(A,LDA,N,DET,JOB)
C***BEGIN PROLOGUE  SPODI
C***DATE WRITTEN   780814   (YYMMDD)
C***REVISION DATE  820801   (YYMMDD)
C***CATEGORY NO.  D2B1B,D3B1B
C***KEYWORDS  DETERMINANT,FACTOR,INVERSE,LINEAR ALGEBRA,LINPACK,MATRIX,
C             POSITIVE DEFINITE
C***AUTHOR  MOLER, C. B., (U. OF NEW MEXICO)
C***PURPOSE  Computes the determinant and inverse of a certain
C            REAL SYMMETRIC POSITIVE DEFINITE matrix (see abstract)
C            using the factors computed by SPOCO, SPOFA or SQRDC.
C***DESCRIPTION
C
C     SPODI computes the determinant and inverse of a certain
C     real symmetric positive definite matrix (see below)
C     using the factors computed by SPOCO, SPOFA or SQRDC.
C
C     On Entry
C
C        A       REAL(LDA, N)
C                the output  A  from SPOCO or SPOFA
C                or the output  X  from SQRDC.
C
C        LDA     INTEGER
C                the leading dimension of the array  A .
C
C        N       INTEGER
C                the order of the matrix  A .
C
C        JOB     INTEGER
C                = 11   both determinant and inverse.
C                = 01   inverse only.
C                = 10   determinant only.
C
C     On Return
C
C        A       If SPOCO or SPOFA was used to factor  A , then
C                SPODI produces the upper half of INVERSE(A) .
C                If SQRDC was used to decompose  X , then
C                SPODI produces the upper half of INVERSE(TRANS(X)*X),
C                where TRANS(X) is the transpose.
C                Elements of  A  below the diagonal are unchanged.
C                If the units digit of JOB is zero,  A  is unchanged.
C
C        DET     REAL(2)
C                determinant of  A  or of  TRANS(X)*X  if requested.
C                Otherwise not referenced.
C                Determinant = DET(1) * 10.0**DET(2)
C                with  1.0 .LE. DET(1) .LT. 10.0
C                or  DET(1) .EQ. 0.0 .
C
C     Error Condition
C
C        A division by zero will occur if the input factor contains
C        a zero on the diagonal and the inverse is requested.
C        It will not occur if the subroutines are called correctly
C        and if SPOCO or SPOFA has set INFO .EQ. 0 .
C
C     LINPACK.  This version dated 08/14/78 .
C     Cleve Moler, University of New Mexico, Argonne National Lab.
C
C     Subroutines and Functions
C
C     BLAS SAXPY,SSCAL
C     Fortran MOD
C***REFERENCES  DONGARRA J.J., BUNCH J.R., MOLER C.B., STEWART G.W.,
C                 *LINPACK USERS  GUIDE*, SIAM, 1979.
C***ROUTINES CALLED  SAXPY,SSCAL
C***END PROLOGUE  SPODI
 
 
