@lisitsyn Okay so both SOBI and FFSep need a function that does this same thing and it has the same name for now. I thought the best solution would be the anon namespace. The other solution would be to have the function as part of the class but then I would either need to make it take SGMatrices etc and then there would be a lot more Eigen::Maps in the code and it would be messier or I would have to include Eigen3 typedefs in the header which I also wasn't wild about.

I thought anon namespace was the best solution, open to other ideas though!