Unit tests for simulating data

[EtienneCmb]

@Mattehub I'm currently writing the unit tests of your function for simulating HOI using gaussians. Can you clarify why :

1. n_triplets = n_nodes / 3
2. Why hard coded values 12? What happens if n_nodes != 12?

[Mattehub]

Thanks, Etienne! I put 12 regions because discussing with you and Andrea if I remember well, we thought that by default the function could create 4 triplets, with syn and red or null interactions among them. In the default, 1 syn, 1 red, and 2 null.

I have a problem with this part, that I think we should discuss tomorrow: I think these functions for the simulation that I created at the beginning and Onur pushed, need to undergo some changes. They are very complex and not very meaningful, I think we should change this part, keeping only the simplest among these functions, in a simplified version. I can do this if for you it is. It should be pretty fast since it is about deleting functions. What do you think about it?

[EtienneCmb]

I completely agree. The code is very redundant and doesn't work as intended. Also, the use of triplet_charachter is not very intuitive.