Markus Holzer authored 4 years ago and Dominik Thoennes committed 4 years ago

also clean up some old leftovers nearby

The default target of \file is the current file.

- checking order of integrator
- checking energy conservation
- added semi implicit euler
- improved documentation
- playground for integrator analysis

How could this have been working until now?
We should not call `cudaFree` on uninitialized memory.

We have to free the old pointers before resize. This also prevents
memory leakage in case the vector gets shrinked.

Apparently the previous code relied on the fact that `resize` somehow
initialized the memory to null pointers or that `cudaFree` just ignores
pointers it didn't allocate.

If load balancing changes the neighborhood, caching of receive
buffers can lead to dead locks.