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SPPDI

       SUBROUTINE SPPDI(AP,N,DET,JOB)
       INTEGER N,JOB
       REAL AP(1)
       REAL DET(2)
 C
 C     SPPDI COMPUTES THE DETERMINANT AND INVERSE
 C     OF A REAL SYMMETRIC POSITIVE DEFINITE MATRIX
 C     USING THE FACTORS COMPUTED BY SPPCO OR SPPFA .
 C
 C     ON ENTRY
 C
 C        AP      REAL (N*(N+1)/2)
 C                THE OUTPUT FROM SPPCO OR SPPFA.
 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        AP      THE UPPER TRIANGULAR HALF OF THE INVERSE .
 C                THE STRICT LOWER TRIANGLE IS UNALTERED.
 C
 C        DET     REAL(2)
 C                DETERMINANT OF ORIGINAL MATRIX 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