nag_ddot (f16eac) Example Program Data
   5                                       : first dot product, n
   1    -1                                 : incx and incy
   0.3                                     : alpha
   1.0   2.0   3.0   4.0   5.0             : Vector x
  -5.0  -4.0   3.0   2.0   1.0             : Vector y

   4                                       : second dot product, n
  -2    -1                                 : incx and incy
  -7.0                                     : alpha
   0.4   0.3   0.2   0.1                   : Vector x
   0.4   0.3   0.2   0.1                   : Vector y