The numerical differentiation in the method `ni_pendulum`, part of `models.py` is artisanal and open to improvement. Implement a standard method. More information [here](https://docs.sympy.org/0.7.6/modules/mpmath/calculus/differentiation.html).
The numerical differentiation in the method
ni_pendulum, part ofmodels.pyis artisanal and open to improvement.Implement a standard method. More information here.