Parallel Circuit With Collisions

breed [top-electrons top-electron]
breed [bottom-electrons bottom-electron]
breed [nuclei nucleus ]

globals [
  top-current bottom-current  ;; current measurements, accumulate for 100 ticks
  last-top-current last-bottom-current  ;; from previous 100 tick period
]

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;;; Setup Procedures ;;;
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to setup
  clear-all
  set-default-shape top-electrons "circle 2"
  set-default-shape bottom-electrons "circle 2"
  
  set-default-shape nuclei "circle 2"
  ;; create the top wire
  ask patches with [top-wire?]
    [ set pcolor gray ]
  ;; create the bottom wire
  ask patches with [not top-wire?]
    [ set pcolor gray + 3 ]

  ;; set up battery negative
  ask patches with [pxcor >= max-pxcor - 4]
    [ set pcolor red ]
  ask patch (max-pxcor - 1) (max-pycor / 2)
    [ set plabel "-" ]

  ;; set up battery positive
  ask patches with [pxcor <= min-pxcor + 4]
    [ set pcolor black ]
  ask patch (min-pxcor + 4) (max-pycor / 2)
    [ set plabel "+" ]

  ;; create electrons in top wire
  ask n-of (100000 / resistance-top-wire) patches with [top-wire?]
    [ sprout-top-electrons 1 [
        set color orange - 2
        set size 1
        if pcolor = black [
        set xcor xcor - 6
      ] ] ]
  ;; create electrons in bottom wire
  ask n-of (100000 / resistance-bottom-wire) patches with [not top-wire?]
    [ sprout-bottom-electrons 1 [
        set color orange - 2
        set size 1
        if pcolor = black [
        set xcor xcor - 6
      ] ] ]
  ask n-of (resistance-top-wire) patches with [top-wire? and pycor > (max-pycor / 2 + 0.1) and pcolor != black and pcolor != red]
    [ sprout-nuclei 1 [
        set color blue
        set size 1.5
         ] ]
  ask n-of (resistance-bottom-wire) patches with [not top-wire? and pycor < (max-pycor / 2 - 0.1) and pcolor != black and pcolor != red]
    [ sprout-nuclei 1 [
        set color blue
        set size 1.5
         ] ]
end 

to-report top-wire?  ;; turtle or patch procedure
  report pycor > max-pycor / 2
end 

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;;; Runtime Procedures ;;;
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to go
  ask top-electrons
    [ move-electron 
      ;; contribute to current measurement
      if pcolor = black [ pu 
        set top-current top-current + 1
        hatch 1
        [ setxy (xcor - 8) ycor
        set color orange - 2
        ]
        die
      ] ]
  ask bottom-electrons
    [ move-electron 
      ;; contribute to current measurement
      if pcolor = black [ pu 
        set bottom-current bottom-current + 1
        hatch 1
        [ setxy (xcor - 8) ycor
        set color orange - 2
        ]
        die
        
      ] ]
  tick
  ;if ticks mod 30 = 0 [ 
  update-plots 
  ;]
end 

;; perform simple point collisions
;; with nuclei in the wire and steadily drifting
;; forward due to the electric field

to move-electron 
let old-patch patch-here
let old-xcor xcor 
let old-ycor ycor 
ifelse not any? nuclei-on neighbors 
 [
   set heading 270 fd 0.5 * voltage 
   ;set heading random 360 fd 0.3 
 ]
 [
   ifelse random-float 1.0 > 0.5 
   [ set heading 2 * heading ;; change direction due to collision 
     fd 0.5 * Voltage       ;; after the collsion, move by the same amount prior to the collision
     set heading random 360 ;; these two rules are just so that electrons don't get trapped between nuclei 
     fd 0.01    
   ]
   [ set heading 180 - 2 * heading ;; change direction due to collision 
     fd 0.5 * Voltage       ;; after the collsion, move by the same amount prior to the collision
     set heading random 360 ;; these two rules are just so that electrons don't get trapped between nuclei 
     fd 0.01    
   ]
 ] 
  ;; have we entered the wrong wire? if so, wrap
  if top-wire? != [top-wire?] of old-patch
    [ setxy old-xcor old-ycor ]
end 

;;;;;;;;;;;;;;;;;;;;;;;;;
;; Plotting Procedures ;;
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to update-plots
  set-current-plot "Current in top wire"
  plotxy (ticks) (top-current / ticks)
;  set last-top-current top-current / 30
;  set top-current 0
;  let top-max plot-y-max
  set-current-plot "Current in bottom wire"
  plotxy (ticks) (bottom-current / ticks)
;  set last-bottom-current bottom-current / 30
;  set bottom-current 0
;  let bottom-max plot-y-max
;  ;; make sure both plots are scaled the same amount
;  set-current-plot "Current in top wire"
;  set-plot-y-range 0 max list top-max bottom-max
;  set-current-plot "Current in bottom wire"
;  set-plot-y-range 0 max list top-max bottom-max
end