TESTING/EIG/dget39.f(3)

NAME
TESTING/EIG/dget39.f

SYNOPSIS

  Functions/Subroutines
subroutine dget39 (rmax, lmax, ninfo, knt)
DGET39

Function/Subroutine Documentation

  subroutine dget39 (double precision rmax, integer lmax, integer ninfo, integer knt)

DGET39

Purpose:

     DGET39 tests DLAQTR, 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 DTRSNA.
     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 DOUBLE PRECISION
              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 dget39.f.

Author

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