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HandyCodeSnippets

1. Testing code in the Observer area of the interface can be very frustrating because if there is an error, it eats the code instead of leaving it up on the screen. The better way is to create a test procedure, and a test button on the interface.

to test

  let x

; [code here]

  show x

end

From the Code Tab: Type your code, try to go to the Interface. If there is an error, NetLogo will flag it and stay on the Code tab. It it doesn't find an error, click the "test" button you created.

Even if NetLogo accepts it, it may not produce the results you expected. In that case, you can go back to the Code tab and refine it.

2. Create a sequential list

;; a useful tool to create a sequence ;; example: u-sequence 3 7 ;; output: [3 4 5 6 7] ;; example: reverse u-sequence 3 7 ;; output: [ 7 6 5 4 3]

to-report u-sequence [ m n ]

  let res []
  let i m
  while [i <= n] [
    set res (lput i res)
    set i (i + 1)
  ]
  report res

end

3. pick a number in a range

to-report pick-a-number [low high]

  ;;validate low <= high before running the report
  let x high - low
  let y random x
  let z y - high
  report z

end

4. to reverse the order of a csv data file requires CSV extension type 'u-reverse-csv' on the observer line overwrites 'reversed.csv' if it exists rename the file after it runs

to u-reverse-csv

  set data read-data user-file
  ;;remove the header and put it at the end
  let header first data
  set data butfirst data
  set data lput header data
  set data reverse data
  ;; Now save the data.  Manually rename the file to your choice when done
  csv:to-file "reversed.csv" data
  set data []
  print "done - changes saved to reversed.csv. Rename the file now."

end