title: How to ask turtles to avoid a patch with specific color at patch-ahead 1 but turtles move forward by bigger number (not fd 1) in one step in NetLogo
body: <p>I am trying to ask turtles with any heading (random 360) to avoid the patches with red color. But, I observed that if a turtle is asked to move " fd 1 + random-float 2.0" then sometime turtles turns (set heading heading - 180) when there is a red patch ahead and sometimes(even most of the times) do not turn. Also when I ask the turtles to move " fd 1 " or " fd 0.1 + random-float 0.9 " the code works all fine. <em>Hopefully the reason behind is the number of patches I am asking the turtles to move in one step.</em> What will be the next patch for the move "fd 0.1 + random-float 0.9" and how could I make this working with patch-ahead 1. My code and the interface is  added. </p>
  
  <p><a href="https://i.stack.imgur.com/5U7HL.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/5U7HL.png" alt="enter image description here"></a></p>
  
  <pre><code>to setup
      clear-all
      ask patches [set pcolor green ]
      ask patches with [pycor = 3] [set pcolor red]
  
     create-turtles 40      
     [ 
        set color blue
        set xcor random-pxcor
        set ycor random-pycor
        set heading random 360
        set size 1
        set speed 1 + random-float 2.0
    ]
  end
  
  to go
    ask turtles [
      fd speed
      avoid-walls
    ]
  end
  
  to avoid-walls
     if [pcolor] of patch-ahead 1 = red [set heading heading - 180]
  end
  </code></pre>