More data sources

We've used only accelerometer, but we could use gyroscope and magnetometer also. This can be done in several ways: you can just merge three time series into one three-dimensional time series or you can train an ensemble of three independent classifiers.

We've also merged x, y, and z of accelerometer into one magnitude value, but you can try to use them as separate time series. In this case, for three motion sensors, you'd have nine time series.