1. A computer-executable method for generating a classifier, the method comprising: receiving a data sequence that includes location coordinates of a moving object over a period of time; grouping contiguous members of the data sequence into an individual feature vector, wherein a respective feature vector corresponds to a respective instance of a sliding time window sliding across the data sequence; generating a feature sequence that includes a plurality of feature vectors, wherein a respective feature vector has dimensionality higher than that of the corresponding individual location coordinates of the data sequence; generating a graph, wherein a respective node of the graph corresponds to a feature vector, and each edge of the graph connects a pair of feature vectors that are adjacent in the feature sequence; converting the generated graph into a two-dimensional graph; displaying, to a user, the two-dimensional graph; receiving user input indicating that a region including two or more nodes of the two-dimensional graph corresponds to a user-specified pattern of motion; and generating a classifier that classifies the two or more nodes as corresponding to the user-specified pattern of motion.