title: declare default value for variables in ampl
body: <p>Now I have variable set x in my ampl model, and I want to define a default value for each x.</p>
  
  <pre><code>set N := 1..10;
  var x {i in N} default 0;
  </code></pre>
  
  <p>If I build the model like this, the initial value of all x would be set as 0. How can I set different value for each x, like [0,0,0,0,0,1,1,1,1,1]?</p>