Richardson derivative extrapolation

Richardson extrapolation of the 1st and 2nd derivative of a single-valued real function in a point.

Function RICHARDSONDER implements the Richardson extrapolation algorithm for the approximation of the 1st and 2nd derivative of the single-valued real function F in the point X0, given an initial step size H_IN for the central difference formulas and the order of the extrapolation N.
The outputs are the two tables of extrapolates for the 1st and 2nd derivative F_PRIME_X0 and F_SECOND_X0. The first column of each table is the array of different step values used, while the other columns contain the derivative extrapolates; each column starting from the 3rd one has a lower order of the error for fixed h than the one on its left (0 entries in the tables are not-computed values). The best approximation is thus the last element of each table (least error and smallest step size).
See RICHARDSONSCRIPT for an example of the usage of the function.