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.