如何强迫海龟只在半个世界里活动

Question

我用命令ask patches with [ pxcor < 0] [set pcolor blue] ask patches with [pxcor > 0] [set pcolor green]创建了一个分为两部分的世界。其中一只海龟有100只，其中5只感染了病毒，另一只也感染了病毒。我的问题是强迫海龟只在它们所在的地方活动。所以我希望pcolor=蓝色的海龟在第二和第三象限(pxcor<0(随机移动，pcolor＝绿色的海龟在第一和第四象限(pxcor>0(。我该怎么办？

这是代码：

turtles-own
[
sick?
sick-time]

to setup
ca
ask patches with [ pxcor < 0 ] [set pcolor blue] ; we want divide the world in two parts: the blue one in the north of Italy
ask patches with [pxcor > 0  ] [set pcolor green]; the white one is the south of Italy
ask patches with [pxcor = 0 ] [set pcolor white ] ; represent the border

create-turtles 200 ; we create a population made up for 200 people
[ set size 1
set shape "person"
set sick-time 0
get-healthy]

ask n-of 100 turtles  ; 100 of this one live in north of Italy
[setxy 12  random-ycor ]

ask n-of 100 turtles ; another 100 in the south
[setxy -12 random-ycor   
]


ask n-of 5 turtles with [pcolor = blue] ; we want infect 5 people for each world
[get-sick ]

ask n-of 5 turtles with [pcolor = green]
[get-sick ]

reset-ticks
end

to get-healthy
set sick? false
set color white
end

to get-sick
set sick? true
set color yellow
set shape "circle"
set sick-time sick-time + 1
end

to go
ask turtles
[
move ]
tick
end

to move
rt random-float 360
fd 1
end

Answer 1

您的移动过程看起来像：

to move
right random-float 360
forward 1
end

如果你想让他们呆在原地，如果移动会让他们进入错误的一半，那么你可以使用patch-ahead来测试他们将要移动的补丁。我认为你想要的是他们不会去不同颜色的补丁。一种方法是：

to move
right random-float 360
if [pcolor] of patch-ahead 1 = pcolor [forward 1]
end

[pcolor] of patch-ahead 1返回前方一个距离单位的补丁的颜色，即乌龟试图移动到的位置。pcolor是乌龟当前站在的补丁的色彩。