More explanatory names for some functions #292
Description
Functions should have a self-explanatory name, especially if one would like to reorganize the library and to locate files in the right places. For example there are several MATLAB source files that are related to nodal coordinates and they should be together.
On the other hand, there are functions such: DI2, DI3, GI1, GI13, GI2, boundaryIdx2D, tfi, ttm, for which it is difficult to guess their value (most of them do not have comments about what they do) in the repository, if they need to be under utilities, if they replicate functionality that already exists, etc.