title: Create simple graph object in Julia using Graphs.jl
body: <p>I am starting to study graph theory (I plan to use it in machine learning and/or bayesian inference). I want to code in Julia, and found the package <a href="http://julia.readthedocs.org/en/latest/packages/packagelist/#graphs-graphs-build" rel="nofollow noreferrer">Graphs</a>. But how can I use this package to create simple graphs? For example, this one:</p>
  
  <p><img src="https://i.stack.imgur.com/820Fl.png" alt="enter image description here"></p>
  
  <p>It would be very useful if I undertood how to create an Julia object that represents this graph using <code>Graphs</code>. Its documentation lacks examples so I can't get started.</p>