將烏龜分配給烏龜自己的變量時出錯

Question

我有一隻烏龜的視錐被定義爲5,120。現在，我希望烏龜用與其朋友相同的顏色分配最近的烏龜。我的代碼返回錯誤

this code can't be run by a patch 

這是我的代碼

turtles-own [ friend ] 

to-report checkForAttraction [ agent ] 
    if [color] of one-of turtles-on empty-patches = [color] of agent [ 
    set friend min-one-of other turtles-on empty-patches with [color = [color] of agent ] [ distance myself ] 
    set attracted? 1 
    ] 
    report actualVelocity 
end 

誤差在

[color = [color] of agent ] 

在第三行顯示出來。這裏有什麼問題？

Answer 1

問題行是with被解析有empty-patches作爲它的代理集參數。由於補丁沒有color變量，因此您無法測試empty-patches的color = [color] of agent，因此出現此錯誤。

但是你不要想測試empty-patches對於那個：你想測試turtles-on empty-patches！

並與一些知名置於括號，您可以：

set friend min-one-of other (turtles-on empty-patches) with [color = [color] of agent ] [ distance myself ]