I want to evaluate the performance of my model, but the problem I have is I have always used a confusion matrix because I have always done models with categorical output (classification). Now, I have this model with numerical output and I find neither a way nor explanation of how to evaluate his performance, and when I use other kernels codes they give me the % accuracy (if it is the accuracy?) and I can't find any references or infer how this % is computed.
So, with a model with output as numerical, how and where can I find techniques of evaluation? (and their explanation, because I don't like to use things I don't understand/know).
I'm working with python.