AbstractsComputer Science

Compressing sparse graphs to speed up Dijkstra’s shortest path algorithm

by Johan Bergdorf

Institution: KTH Royal Institute of Technology
Year: 2015
Keywords: Natural Sciences; Computer and Information Science; Computer Science; Naturvetenskap; Data- och informationsvetenskap; Datavetenskap (datalogi)
Record ID: 1358308
Full text PDF: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-166730


One of the problems that arises from the continuously growing amount of data is that it slows down and limits the uses of large graphs in real world situations. Because of this, studies are being done to investigate the possibility of compressing data in large graphs. This report presents an investigation on the usefulness of compressing sparse graphs and then applying Dijkstra’s shortest path algorithm. A minimal spanning tree algorithm was used to compress a graph and compared with a self-implemented compression algorithm. The minimal distances and how long time it takes for Dijkstra's algorithm to find the shortest path between nodes are investigated. The results show that it is not worth compressing the type of sparse graphs used in this study. It is hard to compress the graph without losing too much of the edges that preserve the shortest paths. The time gained when running Dijkstra's algorithm on the compressed graphs is not enough to compensate for the lack of getting a good shortest path solution.