Calculates finite difference weights for numerical derivatives, including order 0, which amounts to interpolation.
target_point - the point at which the derivative is required grid_points - the points at which the function is given max_order - maximum derivative order
w - finite difference coefficient array with the coefficients for the succes- sive derivatives in rows
Point weights for central schemes on a three-point stencil, where the value is required at the centre:
>> fdweights(0,[-1 0 1],2) ans = 0 1.0000 0 -0.5000 0 0.5000 1.0000 -2.0000 1.0000
The three rows are for interpolation, first derivative and second derivative respectively.
Version 2.2, authors: Bengt Fornberg, Ilya Kuprov