nag_numdiff_fwd (d04aac) Example Program Results

Four separate runs to calculate the first four odd order derivatives of
   f(x) = 0.5*exp(2.0*x-1.0) at x = 0.5.
The exact results are 1, 4, 16 and 64

Input parameters common to all four runs
  xval = 0.500000     nder = -7
(User-supplied callback f, first invocation.)

with step length   0.5000  the results are
Order        Derivative       Questionable?
 1             ---------           Yes
 3             ---------           Yes
 5             ---------           Yes
 7             ---------           Yes

with step length   0.0500  the results are
Order        Derivative       Questionable?
 1             1.000e+00            No
 3             4.000e+00            No
 5             1.600e+01            No
 7             6.400e+01            No

with step length   0.0050  the results are
Order        Derivative       Questionable?
 1             1.000e+00            No
 3             4.000e+00            No
 5             1.600e+01            No
 7             6.404e+01            No

with step length   0.0005  the results are
Order        Derivative       Questionable?
 1             1.000e+00            No
 3             4.000e+00            No
 5             1.599e+01            No
 7             ---------           Yes