- vectorize energy computations
- abstract away inertial force (input: old DOF, velocity, acceleration)
- remove external force in different file than TimeStepper
- check about energy initialization
- boundary condition est functions (have time as input ? -- ABAQUS disp())
- different types of integration schemes (Newmark Beta??)
- pardiso ? (pip install)
- beforeTimestep fn ?
- standardize spring convention
- natural and incremental strain (spring wise)
- allow spring changes in before_step to propogate to energies
- create external force abstract class
- streamline aerodynamic calculations (for sparse)
- Dictionary access to energy objects
- Line search
- Make it both python and ipynb friendly