SpeedUp: New data structures

[JanGaertner]

Storing Volume Integrals

Storing the volume integrals required in equation (4) and (9) of the SoftwareX paper had been done by a List<List<List<Type>>> object. While this is a straight forward approach it is not known to be efficient ([1]).

With the aim to improve efficiency a new data structure List3D is written that uses one large array to store the data. This then also allows to create lists without setting an initial value. However, this is not often used as in most functions an initial value of zero is assumed. For this the function setZero() is used.

A comparison of the new structure with the old implementation however did not show a significant improvement in running time, see attached plot. The dashed line are the results with the new implementation and the solid line the old one.

Most of the time is needed in the calculation of the coefficients which require a lot of operations for the matrix multiplication.
If anyone knows a way to improve this please post an idea :)