Haskell Data Analysis Cookbook

Representing a graph from a list of edges

A graph can be defined by a list of edges, where an edge is a tuple of vertices. In the Data.Graph package, a vertex is simply Int. In this recipe, we use the buildG function to construct a graph data structure out of a list of edges.

Getting ready

We will be constructing the graph represented in the following diagram:

How to do it...

Create a new file, which we will name Main.hs, and insert the following code:

1. Import the Data.Graph package:

   import Data.Graph

2. Construct a graph using the buildG function from the imported library:

   myGraph :: Graph myGraph= buildG bounds edges where bounds = (1,4) edges = [ (1,3), ...