How to solve Repeated column in Grails mapping for entity?

Machine Learning: How does machine learning solve inverse mapping problem?

• If an algorithm can learning the mapping from x to y, e.g. y=f(x), can ML learn the inverse mapping from from y to x? For example, the mapping from y to x1, x2... where, f(x1)=f(x2)=y. Can ML learn g(y) = x1 and g(y) = x2? Normally, the ML would probably generalize the pairs that, g(y) = (x1+x2)/2. Is it a good way to solve that?

• Answer:

  In the typical machine learning problem, xxx is a vector with a bunch of entries, and yyy is either zero or one.  That gives you one covariate with two values and a bunch of labels for your training data, and that's not something that you're going to do well with. If you're trying to learn an invertible function, then you can make this work.  But that's a very special case, and not relevant for most problems.