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listiterationnetlogodistanceoperation

Iterate over a list of distances in Netlogo

I need help for the following issue. Basically, I have four turtles and a list of distances among them, let's say [ 0 1 2 3 ]. Zero is the distance of a turtle from itself. I want to obtein the following list [ 0, 1/5, 2/4, 3/3 ]. In other terms, I want to divide each number to the sum of all the other numbers. Can you help me?

Solution

  • The map primitive allows you to make a calculation for each item in a list separately and returns a new list of the results, as shown by the following examples from the Netlogo dictionary:

    show map round [1.1 2.2 2.7]
=> [1 2 3]
show map [ i -> i * i ] [1 2 3]
=> [1 4 9]

    Now applying this to your case, I let every item of the list be divided by the sum of all items in the list minus its own value:

    to test
  
  let the-list [ 0 1 2 3 ]
  let total sum the-list
  let new-list map [ x -> x / (total - x)] the-list
  
  show new-list
  ;=> [0 0.2 0.5 1]

end