Matching and indexing sequences of different lengths

In this paper, we consider the problem of efficient matching and retrieval of sequences of different lengths. Most of the previous research is concentrated on similarity matching and retrieval of sequences of the same length using Euclidean distance metric. For similarity matching of sequences, we use a modified version of the edit distance function, and consider two sequences matching if a majority of the elements in the sequences match. In the matching process a mapping among non-matching elements is created to check if there are unacceptable deviations among them. This means that two matching sequences should have lengths that are comparable. For efficient retrieval of matching sequences, we propose an indexing scheme which is totally based on lengths and relative distances between sequences. We use vp-trees as the underlying distance-based index structures in our method.