probability for variable value in agentsets, netlo

问题:

I am trying to use probability to assign [0] or [1] individual values for a turtles-own variable in NetLogo, but have only found ways of printing or reporting probability outputs rather than using them to determine a variable value.

Example:

I am asking two turtles to check whether they each want to exchange information with each other, and have assigned a variable exchangeinfo. If exchangeinfo = 0, then no information exchange happens. If exchangeinfo = 1, then information exchange occurs.

Currently I've hard-coded [set exchangeinfo 1] as a placeholder.

But I'd like each turtle to have a 25% chance of exchangeinfo = 1, but I do not want to set variables one at a time.

Any suggestions?

回答1:

@Alan's comment will work. Here is a super simple model that will do what I think you're asking.

turtles-own[exchangeinfo]

to setup
  clear-all
  reset-ticks
  make_turtles
end

to go
  move
  tick
  if (ticks = 1) [inspect turtle 1]
end

to make_turtles
  create-turtles 10
  ask turtles
  [
    set color pink
    set size 2
    set xcor random max-pxcor
    set ycor random max-pycor
    set exchangeinfo 0
  ]
end

to move

  ask turtles
  [right random-float 270
    forward random-float 3
    if ((count (turtles in-radius 2)) > 0)
    [move-to one-of turtles in-radius 2]

  ]

  encounter ;<- this is the function that will decide whether or not to exchange info.

end

to encounter
  ask turtles[
    if (count turtles-here > 0)
    [ifelse (random-float 1 < 0.25)  ;note this is essentially @Alan's answer
      [set exchangeinfo 1]
      [set exchangeinfo 0]
    ]
  ]
end

I'm assuming you'll then want some sort of

ask turtles-here [if (exchangeinfo = 1) [do stuff]]

as well