nag_numdiff_1d_real (d04aac) Example Program Results

Four separate runs to calculate the first four odd order derivatives of
   fun(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 fun, first invocation.)

with step length 0.500000   the results are
Order        Derivative       Error estimate
 1            1.3919e+03           -1.0734e+05
 3           -3.1386e+03           -1.4378e+05
 5            8.7619e+03           -2.4790e+05
 7           -2.4753e+04           -4.4838e+05

with step length 0.050000   the results are
Order        Derivative       Error estimate
 1            1.0000e+00            1.5294e-11
 3            4.0000e+00            2.1125e-09
 5            1.6000e+01            3.8149e-07
 7            6.4000e+01            7.3845e-05

with step length 0.005000   the results are
Order        Derivative       Error estimate
 1            1.0000e+00            1.2768e-14
 3            4.0000e+00            4.1903e-10
 5            1.6000e+01            1.4629e-05
 7            6.4039e+01            2.9729e-01

with step length 0.000500   the results are
Order        Derivative       Error estimate
 1            1.0000e+00            1.4266e-13
 3            4.0000e+00            3.0869e-07
 5            1.5988e+01            6.3314e-01
 7            3.8249e+04           -1.9644e+06