I have a multi-class classification problem with circular and linear data. For example a feature vector contains 20 circular ($\theta \in [0,2\pi)$) and two linear ($\in (0,1)$) variables. I plan to transform $\theta$ into $(\sin\theta,\cos\theta)$ and apply any traditional classifier (MLP, SVM). In fact my data appear to be linearly separable, so I try Perceptron also. I don't find any specific classifier that handles $\theta$ directly. So, is my planning okay? $\sin\theta$ and $\cos\theta$ seem to be highly correlated. Does that create a problem for a classifier?
I appreciate any help and any reference on this issue.