SSIDI(3F)

NAME
     SSIDI   - SSIDI computes the determinant, inertia and inverse of a real
     symmetric matrix using the factors from SSIFA.


SYNOPSYS
      SUBROUTINE SSIDI(A,LDA,N,KPVT,DET,INERT,WORK,JOB)

DESCRIPTION
     On Entry

     A REAL(LDA,N)
        the output from SSIFA.

     LDA INTEGER
        the leading dimension of the array A.

     N INTEGER
        the order of the matrix A.

     KPVT INTEGER(N)
        the pivot vector from SSIFA.

     WORK REAL(N)
        work vector.  Contents destroyed.

     JOB INTEGER
        JOB has the decimal expansion  ABC  where
        If  C .NE. 0, the inverse is computed,
        If  B .NE. 0, the determinant is computed,
        If  A .NE. 0, the inertia is computed.
        For example, JOB = 111  gives all three.  On Return Variables not
     requested by JOB are not used.

     A contains the upper triangle of the inverse of
        the original matrix.  The strict lower triangle
        is never referenced.

     DET REAL(2)
        determinant of original matrix.
        Determinant = DET(1) * 10.0**DET(2)
        with 1.0 .LE. ABS(DET(1)) .LT. 10.0
        or DET(1) = 0.0.

     INERT INTEGER(3)
        the inertia of the original matrix.
        INERT(1)  =  number of positive eigenvalues.
        INERT(2)  =  number of negative eigenvalues.
        INERT(3)  =  number of zero eigenvalues.  Error Condition

     A division by zero may occur if the inverse is requested and  SSICO  has
     set RCOND .EQ. 0.0 or  SSIFA  has set  INFO .NE. 0 .  LINPACK.  This
     version dated 08/14/78 .  James Bunch, Univ. Calif. San Diego, Argonne
     Nat. Lab Subroutines and Functions BLAS SAXPY,SCOPY,SDOT,SSWAP Fortran
     ABS,IABS,MOD