I\'m implementing a nonlinear SVM and I want to test my implementation on a simple not linearly separable data. Google didn\'t help me find what I want. Can you please advise me
You can start with simple datasets like Iris or two-moons both of which are linearly non-separable. Once you are satisfied, you can move on to bigger datasets from the UCI ML repository, classification datasets.
Be sure to compare and benchmark against standard SVM solvers like libSVM and SVM-light.