I am working with legacy physical codes and I develop new ones based on the output of them. They all use their own internal normalization of variables (for example all distances are divided by the physical size of the simulation box) which leads to a mess... The goal, I think, is to have all variables near ~1. On the contrary, my code uses the international system of units to clarify this mess. Since I use floating point double precision, I do not have any problem of denormalization... But my colleagues continue to repeat to me that one should normalize its variables ... without being able to explain me the reasons.
Is it a legacy practice, or there are still excellent reasons to do this ?