Netlogo list updated in time

问题

I'm writing up a code in Netlogo that basically should do the following:

Amongst directed links, interact and seek out their cooperative behavior (coop_b).
Store coop_b in a list variable together with the time of the interaction (reputation_now)
Every interaction, add the reputation_now to a bigger list, reputation_h (reputation history)
- Now, add a time-weight to the reputation, so that the more recently had interactions weigh more in the total reputation. I do this by dividing the encounter time of an interaction by the current time tick, then multiplying that with the coop_b to retrieve a weighted reputation for each interaction. This is stored in the list reputation_h_w (historic reputations weighted). The thing is, this list should be updated every time the members interact, so that earlier additions to the list are now updated to the new time tick. My hunch is this is where my code goes in the mist (problems depicted below the code section).

My code:

to horizontal_interact
  ask members [
    ;set random example variable for coop_b
    set coop_b random-float 5 ; coop-b stands for cooperation behavior
    if ticks > 0 [
    ask my-out-links [ ;there are directed links between all members
      set reputation_now (list [coop_b] of end2 ticks) ;list of coop_b and encounter time
      set reputation_h lput reputation_now reputation_h ; history of reputations, a list of all reputation_now recorded
      foreach reputation_h [ x ->

        let cooperative_behavior item 0 x
        let encounter_time item 1 x

        let reputation_now_w (list cooperative_behavior encounter_time (encounter_time / ticks ))


       ]
    ]
   ]
  ]

end

If I test the content of reputation_h and reputation_h_w with 2 members, I get:

reputation_h is the coop_b variable of the member and the tick of encounter

links> show reputation_h
(link 1 0): 
[[4.0900840358972825 1] 
[0.8885953841506328 2] 
[0.47017368072392984 3]]

(link 0 1): [[3.6805257472366164 1] 
[3.6805257472366164 2] 
[3.4201458793705326 3]]

reputation_h_w (containing the member's coop_b variable, the encounter time and the encounter time divided by the ticks):

links> show reputation_h_w

(link 0 1): [[3.6805257472366164 1 1] 
[3.6805257472366164 1 0.5] 
[3.6805257472366164 2 1] 
[3.6805257472366164 1 0.3333333333333333] 
[3.6805257472366164 2 0.6666666666666666] 
[3.4201458793705326 3 1]]

(link 1 0): [[4.0900840358972825 1 1] 
[4.0900840358972825 1 0.5] 
[0.8885953841506328 2 1] 
[4.0900840358972825 1 0.3333333333333333] 
[0.8885953841506328 2 0.6666666666666666] 
[0.47017368072392984 3 1]]

The problem is that reputation_h_w doesn't make sense to me - firstly there's six inputs instead of three, and secondly, the encounter time (item 1) and the encounter time/ticks (item 2) is off.

What am I doing wrong here?

回答1:

Not sure where you update reputation_h_w in your code, but I'm guessing that you are not resetting it to a blank list before running your foreach loop again. So, it's lput-ing the values at the end of the list, which is not blank anymore.

Example setup:

breed [ as a ]
as-own [ coop_b ]
links-own [ reputation_now reputation_history reputation_history_w]

to setup
  ca
  create-as 2 [
    set coop_b who + 1
    setxy random-pxcor random-pycor
  ]
  while [ any? as with [ not any? my-in-links ] ] [
    ask one-of as with [ not any? my-out-links ] [
      create-link-to one-of other as with [ not any? my-in-links ] [
        set reputation_now []
        set reputation_history []
      ]
    ]  
  ]
  reset-ticks
end

Note that here I will set reputation_history [] right before the foreach chunk runs:

to interact 
  if ticks > 0 [
    ask links [
      set reputation_now ( list [coop_b] of end2 ticks )
      set reputation_history lput reputation_now reputation_history

      ; reset reputation history to a blank list, as you are
      ; recalculating the weighted value at each tick
      set reputation_history_w []
      foreach reputation_history [ x ->
        let behavior item 0 x
        let encounter_time item 1 x
        let fraction encounter_time / ticks
        set reputation_history_w lput ( 
          list behavior encounter_time fraction ) reputation_history_w
      ]       
      show ( word "Current reputation: " reputation_now )
      show ( word "Reputation history: " reputation_history )
      show ( word "Weighted history rep list: " reputation_history_w )
    ]  
  ]
  tick
end

As far as why your ticks are off, I'd guess it's because you are calling tick after you run your horizontal_interact procedure. With the example above, my output looks like:

(link 0 1): "Current reputation: [2 2]"
(link 0 1): "Reputation history: [[2 1] [2 2]]"
(link 0 1): "Weighted history rep list: [[2 1 0.5] [2 2 1]]"
(link 1 0): "Current reputation: [1 2]"
(link 1 0): "Reputation history: [[1 1] [1 2]]"
(link 1 0): "Weighted history rep list: [[1 1 0.5] [1 2 1]]"

even though the ticks read 3. If you run it with tick at the start of the procedure, that might sort out your expected output.

来源：https://stackoverflow.com/questions/47720730/netlogo-list-updated-in-time

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