There are known finite difference approximations for derivatives of first few orders. They are in three groups. Forward, Backward and central.
1. Forward difference gives derivative at the leftmost of points involved in the formula.
2. Backward difference gives derivative at the rightmost of points involved in the formula.
3. central difference gives derivative at the center of points involved in the formula.
I want to know of any known finite difference formula (of any convergence order) that gives derivative(of any order) at any of the points involved.