Preserving sparsity in dynamic network computation

Francesca Arrigo, Desmond J. Higham

Research output: Chapter in Book/Report/Conference proceedingConference contribution book

1 Citation (Scopus)
11 Downloads (Pure)


Time sliced networks describing human-human digital interactions are typically large and sparse. This is the case, for example, with pairwise connectivity describing social media, voice call or physical proximity, when measured over seconds, minutes or hours. However, if we wish to quantify and compare the overall time-dependent centrality of the network nodes, then we should account for the global flow of information through time. Because the time-dependent edge structure typically allows information to diffuse widely around the network, a natural summary of sparse but dynamic pairwise interactions will generally take the form of a large dense matrix. For this reason, computing nodal centralities for a timedependent network can be extremely expensive in terms of both computation and storage; much more so than for a single, static network. In this work, we focus on the case of dynamic communicability, which leads to broadcast and receive centrality measures. We derive a new algorithm for computing time-dependent centrality that works with a sparsified version of the dynamic communicability matrix. In this way, the computation and storage requirements are reduced to those of a sparse, static network at each time point. The new algorithm is justified from first principles and then tested on a large scale data set. We find that even with very stringent sparsity requirements (retaining no more than ten times the number of nonzeros in the individual time slices), the algorithm accurately reproduces the list of highly central nodes given by the underlying full system. This allows us to capture centrality over time with a minimal level of storage and with a cost that scales only linearly with the number of time points.
Original languageEnglish
Title of host publicationComplex Networks & Their Applications V
Subtitle of host publicationProceedings of the 5th International Workshop on Complex Networks and their Applications (COMPLEX NETWORKS 2016)
EditorsHocine Cherifi, Sabrina Gaito, Walter Quattrociocchi, Alessandra Sala
Place of PublicationCham
Number of pages11
ISBN (Print)9783319509013
Publication statusPublished - 30 Nov 2016
Event5th International Workshop on Complex Networks and their Applications - Sala Napoleonica di Palazzo Greppi, Milan, Italy
Duration: 30 Nov 20162 Dec 2016

Publication series

NameStudies in Computational Intelligence
ISSN (Print)1860-949X


Conference5th International Workshop on Complex Networks and their Applications
Abbreviated titleComplex Networks 2016
Internet address


  • time sliced networks
  • human-human digital interactions
  • dynamic communicability
  • time-dependent centrality
  • dynamic broadcast centrality
  • dynamic receive centrality


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