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.)

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.

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.