ergm-package: Fit, Simulate and Diagnose Exponential-Family Models for Networks

Description

ergm is a collection of functions to plot, fit, diagnose, and simulate from exponential-family random graph models (ERGMs). For a list of functions type: help(package='ergm')

For a complete list of the functions, use library(help="ergm") or read the rest of the manual. For a simple demonstration, use demo(packages="ergm").

When publishing results obtained using this package, please cite the original authors as described in citation(package="ergm").

All programs derived from this package must cite it.

Arguments

Details

Recent advances in the statistical modeling of random networks have had an impact on the empirical study of social networks. Statistical exponential family models (Strauss and Ikeda 1990) are a generalization of the Markov random network models introduced by Frank and Strauss (1986), which in turn derived from developments in spatial statistics (Besag, 1974). These models recognize the complex dependencies within relational data structures. To date, the use of stochastic network models for networks has been limited by three interrelated factors: the complexity of realistic models, the lack of simulation tools for inference and validation, and a poor understanding of the inferential properties of nontrivial models.

This manual introduces software tools for the representation, visualization, and analysis of network data that address each of these previous shortcomings. The package relies on the network package which allows networks to be represented in R. The ergm package implements maximum likelihood estimates of ERGMs to be calculated using Markov Chain Monte Carlo (via ergm). The package also provides tools for simulating networks (via simulate.ergm) and assessing model goodness-of-fit (see mcmc.diagnostics and gof.ergm).

A number of Statnet Project packages extend and enhance ergm. These include tergm (Temporal ERGM), which provides extensions for modeling evolution of networks over time; ergm.count, which facilitates exponential family modeling for networks whose dyadic measurements are counts; and ergm.userterms, which allows users to implement their own ERGM terms.

For detailed information on how to download and install the software, go to the ergm website: statnet.org. A tutorial, support newsgroup, references and links to further resources are provided there.

References

Admiraal R, Handcock MS (2007). networksis: Simulate bipartite graphs with fixed marginals through sequential importance sampling. Statnet Project, Seattle, WA. Version 1, statnet.org.

Bender-deMoll S, Morris M, Moody J (2008). Prototype Packages for Managing and Animating Longitudinal Network Data: dynamicnetwork and rSoNIA. Journal of Statistical Software, 24(7). http://www.jstatsoft.org/v24/i07/.

Besag, J., 1974, Spatial interaction and the statistical analysis of lattice systems (with discussion), Journal of the Royal Statistical Society, B, 36, 192-236.

Boer P, Huisman M, Snijders T, Zeggelink E (2003). StOCNET: an open software system for the advanced statistical analysis of social networks. Groningen: ProGAMMA / ICS, version 1.4 edition.

Butts CT (2006). netperm: Permutation Models for Relational Data. Version 0.2, http://erzuli.ss.uci.edu/R.stuff.

Butts CT (2007). sna: Tools for Social Network Analysis. Version 1.5, http://erzuli.ss.uci.edu/R.stuff.

Butts CT (2008). network: A Package for Managing Relational Data in R. Journal of Statistical Software, 24(2). http://www.jstatsoft.org/v24/i02/.

Butts CT, with help~from David~Hunter, Handcock MS (2007). network: Classes for Relational Data. Version 1.2, http://erzuli.ss.uci.edu/R.stuff.

Frank, O., and Strauss, D.(1986). Markov graphs. Journal of the American Statistical Association, 81, 832-842.

Goodreau SM, Handcock MS, Hunter DR, Butts CT, Morris M (2008a). A statnet Tutorial. Journal of Statistical Software, 24(8). http://www.jstatsoft.org/v24/i08/.

Goodreau SM, Kitts J, Morris M (2008b). Birds of a Feather, or Friend of a Friend? Using Exponential Random Graph Models to Investigate Adolescent Social Networks. Demography, 45, in press.

Handcock, M. S. (2003) Assessing Degeneracy in Statistical Models of Social Networks, Working Paper #39, Center for Statistics and the Social Sciences, University of Washington. www.csss.washington.edu/Papers/wp39.pdf

Handcock MS (2003b). degreenet: Models for Skewed Count Distributions Relevant to Networks. Statnet Project, Seattle, WA. Version 1.0, statnet.org.

Handcock MS, Hunter DR, Butts CT, Goodreau SM, Morris M (2003a). ergm: A Package to Fit, Simulate and Diagnose Exponential-Family Models for Networks. Statnet Project, Seattle, WA. Version 3, statnet.org.

Handcock MS, Hunter DR, Butts CT, Goodreau SM, Morris M (2003b). statnet: Software Tools for the Statistical Modeling of Network Data. Statnet Project, Seattle, WA. Version 3, statnet.org.

Hunter, D. R. and Handcock, M. S. (2006) Inference in curved exponential family models for networks, Journal of Computational and Graphical Statistics, 15: 565-583

Hunter DR, Handcock MS, Butts CT, Goodreau SM, Morris M (2008b). ergm: A Package to Fit, Simulate and Diagnose Exponential-Family Models for Networks. Journal of Statistical Software, 24(3). http://www.jstatsoft.org/v24/i03/.

Krivitsky PN, Handcock MS (2007). latentnet: Latent position and cluster models for statistical networks. Seattle, WA. Version 2, http://statnet.org.

Krivitsky PN (2012). Exponential-Family Random Graph Models for Valued Networks. Electronic Journal of Statistics, 2012, 6, 1100-1128. http://dx.doi.org/10.1214/12-EJS696{doi:10.1214/12-EJS696}

Morris M, Handcock MS, Hunter DR (2008). Specification of Exponential-Family Random Graph Models: Terms and Computational Aspects. Journal of Statistical Software, 24(4). http://www.jstatsoft.org/v24/i04/.

Strauss, D., and Ikeda, M.(1990). Pseudolikelihood estimation for social networks Journal of the American Statistical Association, 85, 204-212.