The Data look something like this:
[0, ...., 0, 2.8, 10, 4.5,]
So there are a lot of zeros to predict. And just a few non zeroes.
Apllying R2 to a potentially predictive model for this kind of Data is not feaseable: The difference between all zero prediction and the expected values is not that big.
Is there a R2-like metric to aid this situation ?