turtle粘合patch的运动问题

lincw

请问：
随机产生的turtle 已经在patch的坐标上上下左右一格格运动，当turtle碰到一个随即分布的patch以一定概率粘合,patch变色，其他turtle经过也还是以一定概率粘合的，粘合后turtle的能量就会转变到patch上，并且以一定速率消耗它，怎么编写这个过程？下面是我编写的，运行时就出错了。怎么改正呢？
9 U( M, d$ V8 t+ n
% m- b! A* [8 }
1 z" ]3 i, S2 f) I9 W2 h& vturtles-own [ energy ]
to setup
1 X; _$ |; a* pclear-all
, o8 y7 I; L) n0 u4 uset-default-shape turtles "square"
) e  w3 |% _$ icrt nutrition
- k" m1 \( f  a; wask turtles[
    set color white
7 ?7 O" M$ O+ Z8 [3 }5 k2 T, B! D    setxy random-pxcor random-pycor]
7 [, N! D5 G% ?$ p  
ask n-of microbes-initialization patches
/ N1 {# r) }. m5 z    [ set pcolor green]
* B8 Z6 O# ~( Y# V6 l- D ask turtles [set energy  1]
end

to go
    ask turtles [set heading 90 * random 4    fd 1]
     ask patches  with [ any? turtles-here]
    [  if pcolor = green and random 100 < chance-of-congregating [tt ]]
     ask turtles [ if energy = 0  [die ]]
! `' X/ d' @4 A$ p# T& l end
- `0 h7 y. J+ d; u
to tt
3 m3 S. C- o% s6 d/ D( gask patches [set pcolor gray ]
ask  turtles [set energy energy - 1]
end

lincw

谢谢楼上两位，后来自己用两种turtle来表示暂时把问题解决了，以后再出现难题再向你们请教啊