title: Rotating a turtle through cone of vision
body: <p>I wish to write to where I have a cone-of-vision <strong>cone angle</strong> for the turtle.</p>
  
  <p>And I rotate the turtle through the cone-of-vision.</p>
  
  <p>Therefore, first it's heading the start of cone-of-vision and with a increment of 0.05 degree it changes till it reaches the end of cone-of-vision</p>
  
  <pre><code>  let max-head heading + (cone-angle / 2)
    set heading subtract-headings heading (zero-dash / 2)
  
    while[(subtract-headings heading max-head ) &lt; 0]
    [
    set heading heading + .05
    ;wait 0.1
    ]
  </code></pre>
  
  <p>The above code I wrote isnt correct. But I can't find the mistake.</p>