# 2: Graphs

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The next three chapters are about systems made up of components and connections between components. For example, in a social network, the components are people and connections represent friendships, business relationships, etc. In an ecological food web, the components are species and the connections represent predator-prey relationships.

In this chapter, I introduce NetworkX, a Python package for building models of these systems. We start with the Erdős-Rényi model, which has interesting mathematical properties. In the next chapter we move on to models that are more useful for explaining real-world systems.

The code for this chapter is in chap02.ipynb in the repository for this book. More information about working with the code is in Section 0.3.

This page titled 2: Graphs is shared under a CC BY-NC-SA 3.0 license and was authored, remixed, and/or curated by Allen B. Downey (Green Tea Press) .