TESTING/EIG/sget39.f(3)    Library Functions Manual    TESTING/EIG/sget39.f(3)

NAME
       TESTING/EIG/sget39.f

SYNOPSIS
   Functions/Subroutines
       subroutine sget39 (rmax, lmax, ninfo, knt)
           SGET39

Function/Subroutine Documentation
   subroutine sget39 (real rmax, integer lmax, integer ninfo, integer knt)
       SGET39

       Purpose:


            SGET39 tests SLAQTR, a routine for solving the real or
            special complex quasi upper triangular system

                 op(T)*p = scale*c,
            or
                 op(T + iB)*(p+iq) = scale*(c+id),

            in real arithmetic. T is upper quasi-triangular.
            If it is complex, then the first diagonal block of T must be
            1 by 1, B has the special structure

                           B = [ b(1) b(2) ... b(n) ]
                               [       w            ]
                               [           w        ]
                               [              .     ]
                               [                 w  ]

            op(A) = A or A', where A' denotes the conjugate transpose of
            the matrix A.

            On input, X = [ c ].  On output, X = [ p ].
                          [ d ]                  [ q ]

            Scale is an output less than or equal to 1, chosen to avoid
            overflow in X.
            This subroutine is specially designed for the condition number
            estimation in the eigenproblem routine STRSNA.

            The test code verifies that the following residual is order 1:

                 ||(T+i*B)*(x1+i*x2) - scale*(d1+i*d2)||
               -----------------------------------------
                   max(ulp*(||T||+||B||)*(||x1||+||x2||),
                       (||T||+||B||)*smlnum/ulp,
                       smlnum)

            (The (||T||+||B||)*smlnum/ulp term accounts for possible
             (gradual or nongradual) underflow in x1 and x2.)

       Parameters
           RMAX

                     RMAX is REAL
                     Value of the largest test ratio.

           LMAX

                     LMAX is INTEGER
                     Example number where largest test ratio achieved.

           NINFO

                     NINFO is INTEGER
                     Number of examples where INFO is nonzero.

           KNT

                     KNT is INTEGER
                     Total number of examples tested.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Definition at line 102 of file sget39.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0         TESTING/EIG/sget39.f(3)