Consider a set of 7D vectors. Each vector belongs to one of four classes.
After mapping to 3D with PCA and coloring each point according its class the dataset looks like as shown below:
For the animated GIF version, click here https://docs.google.com/open?id=0B26-1RYIJR_oOWRmSXZyWUl4M2M
What classification technique would be suitable for this dataset (e.g. decision trees, neural networks, etc) ?