使用 netlogo 的随机游走重新路由问题

Question

我使用以下代码创建了一个小型网络并实现了随机游走算法。我使用一些节点作为目标，其中步行者最初放置在一个节点上。我使用带有walker 的路径（walker-own 变量）列表来保存它的位置。

问题：如何防止 walker 不返回那些已经访问并列在其内存（列表）中的节点。 我是 Netlogo 的新手，无法实现这个逻辑。

breed [nodes node]
breed [walkers walker]

walkers-own [location path]  
nodes-own [ target? visited? ] 

to setup
  clear-all
  set-default-shape nodes "circle"
  create-nodes 30 [ 
    set color blue 
    set target? false
    set visited? false
  ]
  ask nodes [ create-link-with one-of other nodes ]
  repeat 500 [ layout ]
  ask nodes [ 
    setxy 0.95 * xcor 0.95 * ycor 
  ]
  ask n-of 5 nodes [
    set target? true
    set color white
  ]

  create-walkers 1 [
    set color red
    set location one-of nodes
    move-to location
    set path (list location path)
  ]
  reset-ticks
end

to layout
  layout-spring nodes links 0.5 2 1
end

to go
  ask links [ set thickness 0 ]
  ask walkers [
    let new-location one-of [link-neighbors] of location
    move-to new-location
    set location new-location
    set path lput location
    ;; This gets turtles to ask their current location 
    ;; to set visited and target to true.
    ask location [
      set visited? true
      if target? = true [
        set color red
      ]
    ]
  ]

  ;; Check for target nodes that have NOT been visited. 
  ;; If there aren't any, stop the model.
  if not any? nodes with [ target? = true and visited? = false ] [
   print ("All target nodes have been visited.")
   stop
  ] 
  tick
end

Answer 1

您可能想要let new-location one-of [link-neighbors] of location with [not visited] 之类的东西。但是，如果没有，这将产生错误。所以试试这样的。

to go
  ask links [ set thickness 0 ]
  ask walkers [
    let candidate-locations ([link-neighbors] of location) with [not visited?]
    ifelse any? candidate-locations
    [ let new-location one-of candidate-locations
      move-to new-location
      set location new-location
      set path lput location
      ;; This gets turtles to ask their current location 
      ;; to set visited and target to true.
      ask location [
        set visited? true
        if target? = true [ set color red ]
      ]
    ]
    [;;whatever you want to do if all possible paths are blocked
    ]
  ]

  ;; Check for target nodes that have NOT been visited. 
  ;; If there aren't any, stop the model.
  if not any? nodes with [ target? = true and visited? = false ] [
   print ("All target nodes have been visited.")
   stop
  ] 
  tick
end