In one embodiment, a method includes receiving real-time sensor data from N sensors on the computing device. The real-time sensor data corresponds to a transition in a physical state of the computing device caused by a user of the computing device. The method also includes applying a linear function to the real-time sensor data from each of the N sensors; determining a vector based on an N-tuple comprising the derivatives; comparing the vector with a pre-determined hyperplane with N−1 dimensions; and determining based on the comparison whether the transition is an event corresponding to any of one or more pre-determined imminent uses of the computing device by the user or a non-event not corresponding to any of the pre-determined imminent uses of the computing device by the user.