title: Netlogo: How can I ask the specific patch changes the color (black) only for a specific ticks with the timing of Poisson distribution?
body: <p>How can I ask the specific patch changes the color (black) only for a specific ticks with the timing of Poisson distribution? I am a beginner of Netlogo. The following is a sample program. But in this program the patch has been white colored all the time. Thank you.</p>
  
  <pre><code>ask patch max-pxcor 0 [
  set poisson poisson - 1
  if poisson &lt; 0 [ ;I have no idea of the good condition setting.
    set poisson random-poisson (stop-ticks)
    set pcolor black 
  ]
    set pcolor white
  ]
  </code></pre>