TESTING/EIG/dget31.f(3)

NAME
TESTING/EIG/dget31.f

SYNOPSIS

  Functions/Subroutines
subroutine dget31 (rmax, lmax, ninfo, knt)
DGET31

Function/Subroutine Documentation

  subroutine dget31 (double precision rmax, integer lmax, integer, dimension( 2 ) ninfo, integer knt)

DGET31

Purpose:

    !>
    !> DGET31 tests DLALN2, a routine for solving
    !>
    !>    (ca A - w D)X = sB
    !>
    !> where A is an NA by NA matrix (NA=1 or 2 only), w is a real (NW=1) or
    !> complex (NW=2) constant, ca is a real constant, D is an NA by NA real
    !> diagonal matrix, and B is an NA by NW matrix (when NW=2 the second
    !> column of B contains the imaginary part of the solution).  The code
    !> returns X and s, where s is a scale factor, less than or equal to 1,
    !> which is chosen to avoid overflow in X.
    !>
    !> If any singular values of ca A-w D are less than another input
    !> parameter SMIN, they are perturbed up to SMIN.
    !>
    !> The test condition is that the scaled residual
    !>
    !>     norm( (ca A-w D)*X - s*B ) /
    !>           ( max( ulp*norm(ca A-w D), SMIN )*norm(X) )
    !>
    !> should be on the order of 1.  Here, ulp is the machine precision.
    !> Also, it is verified that SCALE is less than or equal to 1, and that
    !> XNORM = infinity-norm(X).
    !>

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 array, dimension (2)
    !>          NINFO(1) = number of examples with INFO less than 0
    !>          NINFO(2) = number of examples with INFO greater than 0
    !>

    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 90 of file dget31.f.

Author

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