Local Routing on Complex Network using Netlogo

Question

I created a small undirected network, where some nodes are as sources and some are targets. then I created walkers placed on source nodes. Now, I want to implement a very simple local routing algorithm using this network. Here, my algo steps;

1 go
2 get-list-of-neighbors
3 select one-of from list of neighbors
    check is-visited:
    if yes: [remove from the list 
           check is-loop
           if yes: Die
           else go to setp 3]

  4 else Move-to selected node
  5 check is-target?
    if yes: die 
    else add to list-of-visited and Go

Question: I'm new to Netlog, and don't know how to implement this algorithm. Here is my code.

to go
ask walkers[
set list-of-neighbors (list [link-neighbors] of location)
let selected-node one-of list-of-neighbors
if (visited?=true)[ set list-of-neighbors remove-duplicate list-of-neighbors
chek if loop? exist
     if yes:
     if no:
if(visited?=false)[ move-to selected-node]
set location selected-node
ask location[ ifelse target=true[die][set list-of-visited lput location 
go ]
end

Answer 1

My Question/ algorithm Description:

1. Walker Start from Source node
2. At each node, each walker chooses the next node of its neighbor's
3. If all the neighboring nodes have not been visited, then the next neighbor is chosen among the nodes that have not been visited
4. If all the neighboring nodes have been visited previously, then the next node is chosen uniformly among all the neighbors. The walker is forced to return to a previously visited node
5. If a cycle is detected, that is, the walker has to die
6. If all targets are visited, the model stops

Answer 2

My answer here is a slight modification to my answer to your other question. I'm not sure exactly what you mean by check is-loop, so in my solution I just have the walkers die if they have no neighboring nodes to which they can move (as they have already visited that node). Additionally, I'm suggesting a slightly different approach to accomplish the same idea as the algorithm you outline. The steps here are more like:

• Walker selects one of the neighbors to which it has not already moved
• If no such neighbor exists (as it has already visited all neighbors of its current location) the walker dies.
• If a neighbor that has not been visited does exist, the walker will move to that neighbor, and add its new location to its variable locations-list
• If the new location is a target:
  1. Target node is marked as visited
  2. Target node changes its color
  3. The walker dies
• If no walkers remain at the end of the go procedure, a new walker is spawned on the source node.
• If all targets are visited, the model stops

Obviously if there is a linear path with multiple target nodes on it, the walkers will die each time they come to the first target and so will never visit those nodes that are farther along- but this is just an example. Remove the die chunk or modify other things to play around.

Like I said, this is only a very small modification to the answer linked above, but I copy the whole code below for easy access.

breed [nodes node]
breed [walkers walker]

walkers-own [location locations-list]  
nodes-own [ source? target? visited? ] 

to setup
  clear-all
  set-default-shape nodes "circle"
  create-nodes 30 [ 
    set color blue 
    set target? false
    set source? 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 3 nodes [
    set target? true
    set color white
  ]

  ask n-of 1 nodes with [ target? = false ] [
    set source? true
    set color green
  ]

  spawn-walkers

  reset-ticks
end

to layout
  layout-spring nodes links 0.5 2 1
end

to spawn-walkers

    create-walkers 1 [
    set color red
    set location one-of nodes with [ source? ]
    move-to location
    set locations-list ( list location)
  ]

end

to go
  ask links [ set thickness 0 ]
  ask walkers [
    let new-location one-of ( [link-neighbors] of location ) with [ not member? self [locations-list] of myself ]
    ifelse new-location = nobody [
      print "I'm stuck!"
      die
    ]
    [
      move-to new-location
      set location new-location
      set locations-list lput location locations-list 
      ask location [ 
        set visited? true
        if target? = true [
          set color color + 1
          ask myself [
            die
          ]
        ]
      ]
    ]
  ]

  if not any? nodes with [ target? = true and visited? = false ] [
    print ("All target nodes have been visited.")
    stop
  ]

  if count walkers < 1 [
    spawn-walkers
  ]  

  tick
end