title: Fixing a variable in JuMP / Julia
body: <p>I have an AMPL code like this:</p>
  
  <pre><code>param N;
  set R := 1..N;
  set V := 1..N;
  initializeSendPrepareReq{i in R, v in V}: SendPrepReq[1, i, v] = 0;
  </code></pre>
  
  <p>I need to write it in Julia using JuMP.</p>
  
  <pre><code>N = 10
  R = 1:N
  V = 1:N
  ?
  </code></pre>
  
  <p>I know I probably need to use JuMP.fix() but don't know how. Thank you</p>