Extracts the Backbone from Weighted Graphs

Provides methods for extracting from a weighted graph a binary or signed backbone that retains only the significant edges. The user may input a weighted graph, or a bipartite graph from which a weighted graph is first constructed via projection. Backbone extraction methods include the stochastic degree sequence model (Neal, Z. P. (2014). ), hypergeometric model (Neal, Z. (2013). ), the fixed degree sequence model (Zweig, K. A., and Kaufmann, M. (2011). ), fixed column model, fixed fill model, as well as a universal threshold method.