check_*_domain should fail when the same domain is given as a source and a target

[kachayev]

This check is currently not implemented.

[BuenoRuben]

hey, sorry but I'm not sure I understood what the function is exactly supposed to do:
is it supposed to check if two domains have the same name (1 and -1 as an exemple),
or is it supposed to check if two domains, one from target and another from source, have the same elements

[kachayev]

@BuenoRuben The idea here is that a specific domain should be included either as source or as a target. Which means that the domain id is either consistently positive or consistently negative. Let's say the id of the domain is 3. It should either be 3 (source) or -3 (target). There shouldn't be a situation where we have both 3 and -3 in the sample_domain.

[kachayev]

The one place where this happens (and is necessary) is Leave-One-Domain-Out splitter for model selection.

[BuenoRuben]

Thanks you for your answer, I will take a look at those functions