dget39()

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

[out]	RMAX	RMAX is DOUBLE PRECISION Value of the largest test ratio.
[out]	LMAX	LMAX is INTEGER Example number where largest test ratio achieved.
[out]	NINFO	NINFO is INTEGER Number of examples where INFO is nonzero.
[out]	KNT	KNT is INTEGER Total number of examples tested.

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.