我该如何解决该错误（您不能在补丁程序上下文中使用my_区域，它仅适用于乌龟）？

Posted 2021-03-27

如果我之前定义的批次，我希望海龟再次回到它们的区域。问题是我遇到了错误

you can not use my_ area in a patch context, it is a turtle-only 

按钮是

to back_from_event

  ask turtles with [ area = 1 ]  [ move-to one-of patches with [ (not any? other turtles-here) and ( area = my_area )  ] ]

end

如下定义的斑块和海龟在区域（2,3,4,5）中，并移至区域1，我需要它们再次回到该区域：

to define_areas

  ask patches with [ (pxcor > -3) and (pxcor < 3) and (pycor > -3) and (pycor < 3) ] [  set pcolor white set area 1    ]
  ask patches with [ (pxcor > 5 ) and (pxcor < 16 ) and (pycor > 4) and (pycor < 16) ] [  set pcolor white set area 2     ]
  ask patches with [ (pxcor < -5 ) and (pxcor > -16 ) and (pycor > 4) and (pycor < 16) ] [  set pcolor white set area 3    ]
   ask patches with [ (pxcor < -5 ) and (pxcor > -16 ) and (pycor < -4) and (pycor > -16) ] [  set pcolor white set area 4    ]
  ask patches with [ (pxcor > 5 ) and (pxcor < 16 ) and (pycor < -4) and (pycor > -16) ] [  set pcolor white set area 5   ]

end

答案

您将'area'作为补丁变量，将'my_area'作为turtle变量。

您需要意识到的是，要修补的乌龟是唯一的，因为一次只能将一只乌龟放在一个地方。因此，乌龟无需指定补丁即可访问其所坐补丁所拥有的变量。这样的代码就可以了：

ask turtles with [area = 1] [ ]

这是因为它等效于：

ask turtles with [ [area] of patch-here = 1] [ ]

但是，一个补丁无法访问一个乌龟拥有的变量，因为同一补丁上可能有多个乌龟。例如，如果您要求某个色块将其pcolor设置为color，并且该色块上有红色乌龟和蓝色乌龟，它怎么知道要选择哪种颜色？

您的错误说：“您不能在补丁程序上下文中使用my_area，它仅适用于乌龟”。就是说，您尝试使用my_area变量来打补丁，但该变量归海龟所有。因此，您没有告诉它从哪只乌龟那里获得my_area。
这是您拥有的：
to back_from_event
  ask turtles with [ area = 1 ]
  [ move-to one-of patches with [(not any? other turtles-here) and (area = my_area)] 
  ]
end

我假设您希望补丁的面积与执行询问的乌龟的my_area相同。那就是myself的目的。

to back_from_event
  ask turtles with [ area = 1 ]
  [ move-to one-of patches with [(not any? other turtles-here) and (area = [my_area] of myself)] 
  ]
end