The problem is to predict metal or rock objects from sonar return data. Each pattern is a set of 60 numbers in the range 0.0 to 1.0. Each number represents the energy within a particular frequency band, integrated over a certain period of time. The label associated with each record contains the letter R if the object is a rock and M if it is a mine (metal cylinder).
The numbers in the features are in increasing order of aspect angle, but they do not encode the angle directly.
https://archive.ics.uci.edu/ml/datasets/Connectionist+Bench+(Sonar,+Mines+vs.+Rocks)