I've been working on a machine learning project for a while and I've come up with an algorithm that does what I want it to do (predict some values). I wondered if it is possible to calculate R-squared for my results.
My results are like this (test):
Predictions Observations: 4.25 4.30 4.15 4.25 3.70 3.75 3.25 3.15 ...
How can I calculate R-squared for this?