title: NetLogo - compare single agent against many agents (expected input not list)
body: <p>I am first time poster, six month reader. I love this site and am grateful for the vast array of topics covered. Now that I am feeling a bit more competent using NetLogo, I've tried some harder stuff and got stuck...</p>
  
  <p>Basically, I have created a membership function which measures agents against one another on a vector containing two variables (opinions on rock and hip-hop):</p>
  
  <pre><code>to-report membership [ agent1 agent2 ]
  let w 0.5
  let w2 sq w
  report exp (- d2 agent1 agent2 / w2)
  end
  </code></pre>
  
  <p>where</p>
  
  <pre><code>;;;;;;;;;;;;;;Shortcut functions;;;;;;;;;;;;;;;;;;;;;;;;;;;
  
  to-report d2 [agent1 agent2 ]
    report ( (sq ([rock] of agent1 - [rock] of agent2)) + (sq ([hip-hop] of agent1 - [hip-hop] of agent2)) )
  end
  
  to-report sq [ x ]
    report x * x
  end
  </code></pre>
  
  <p>This all works fine, and I am able to compare any two agents without problem.
  However, my trouble arises when I try to compare a single agent [agent1] with all of the agents within his neighbourhood.</p>
  
  <pre><code>to go
      ask turtles [
      let neighbours turtle-set turtles in-radius neighbourhood
      show membership self neighbours] 
  end
  </code></pre>
  
  <p>Whenever I run this model I receive an error that the d2 reporter expected an input not a list - which I theoretically understand - by having a neighbourhood of 1+ agent(s), the calculation is receiving for example [0.1 0.8] [0.2 0.4] [0.5 0.6].............. </p>
  
  <p>I was just wondering, is there any way that the procedure can consider all of the neighbours and arrive at one single membership number? I have searched extensively through posts and a couple of netlogo books I have, but no luck so far. Thank you for taking the time to read this post and for any helpful comments.</p>