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新手,在看netlogo自带的例子时,有几行程序看不懂,希望高手能够指点。# y! ?6 U6 P9 h4 I, |8 C
netlogo自带的social science--traffic grid这一例子当中,
; \ j; i% S8 H8 C5 |; @% iglobals
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, [2 X% V3 ^: L0 b grid-x-inc ;; the amount of patches in between two roads in the x direction
+ u( L* l/ t1 h/ F! |: P grid-y-inc ;; the amount of patches in between two roads in the y direction: S- w: T, t3 e/ V. \6 h
acceleration ;; the constant that controls how much a car speeds up or slows down by if# |; c3 o7 I2 z9 }" w/ s* X7 F
;; it is to accelerate or decelerate
1 o& C+ I' m, x phase ;; keeps track of the phase M$ M) n# [) @* ^8 R8 v
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
+ g& B; F% }8 m& ` current-light ;; the currently selected light# E4 o8 I: {7 u. x5 v! J+ y
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;; patch agentsets; ?/ C* u0 g! l* [1 ]" g
intersections ;; agentset containing the patches that are intersections* e+ V8 M! l" v( t( T
roads ;; agentset containing the patches that are roads# S. P @, O5 o
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j& {- q* Y$ K; r& |8 K/ Gturtles-own: e( |+ H- L. J6 b5 e- W9 E4 @& S& R E
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& `% r* l a# P* m% ^ speed ;; the speed of the turtle3 I9 R( s' }# O! P/ j0 ]6 j
up-car? ;; true if the turtle moves downwards and false if it moves to the right
5 f4 s& I% L% {4 l8 Q& b c wait-time ;; the amount of time since the last time a turtle has moved) a1 s9 ^% a8 c* @
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patches-own# T7 j* l- ~( P
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intersection? ;; true if the patch is at the intersection of two roads
9 L+ ]$ N; M5 f" k3 ~% W. ^ green-light-up? ;; true if the green light is above the intersection. otherwise, false.3 Z! g1 Y+ b% u3 }
;; false for a non-intersection patches.: P2 k( m, z0 R0 A J* f. q
my-row ;; the row of the intersection counting from the upper left corner of the
* a5 J# W6 C5 G/ x6 I+ f ;; world. -1 for non-intersection patches.
7 a, w, X5 @8 `# c5 W2 Q& Y my-column ;; the column of the intersection counting from the upper left corner of the0 A$ g8 { G' {) |/ U! c
;; world. -1 for non-intersection patches.
0 F- ` i0 f/ j6 b2 j% z my-phase ;; the phase for the intersection. -1 for non-intersection patches.
, M+ q1 U& d& c3 l8 ] auto? ;; whether or not this intersection will switch automatically.
& O+ Z2 H# ^$ H7 C ;; false for non-intersection patches.
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3 e* W! k8 [" \1 Q;;;;;;;;;;;;;;;;;;;;;;+ Q) v8 M* C, Z* n% @% m- ]
;; Setup Procedures ;;4 ]! F% s# {6 X
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.% R5 N9 S+ s* Y, F2 G* a
;; Create num-cars of turtles if there are enough road patches for one turtle to
3 Y, Y7 X; i2 x;; be created per road patch. Set up the plots.
* L+ Y, H# V1 e0 z1 k g0 ?to setup
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6 {8 Z2 z# o* E1 D) |" { setup-globals2 p! A! H" F3 y+ Q% o
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;; First we ask the patches to draw themselves and set up a few variables5 P$ A+ e. i5 A8 `
setup-patches
* S$ q: s% G9 X# o% f3 W9 b \ make-current one-of intersections- n6 N6 h/ w. D# \; r Y: q
label-current- v. f& B& O( \1 Z' A( ^1 e4 v
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set-default-shape turtles "car"
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, c) K% ?& ] @8 ]: h if (num-cars > count roads)2 P; Q- L- X8 j' v; @
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user-message (word "There are too many cars for the amount of " V" v0 x# l( [# q$ S# s
"road. Either increase the amount of roads "
% w7 m! O2 f: R r5 X5 } "by increasing the GRID-SIZE-X or "
0 d9 A& _" `4 R6 c "GRID-SIZE-Y sliders, or decrease the "
8 J6 L; X- U& ~6 o "number of cars by lowering the NUMBER slider.\n"$ i! \3 O& E5 Z2 C, m
"The setup has stopped.")! p* R% e P3 n- s
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
: p1 r8 c$ d& q4 p) g5 F9 R/ W crt num-cars7 s4 i9 n+ l" w5 V
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; Z5 @" z/ K/ F4 Z# l6 m. i$ s setup-cars: y7 L: a$ `- r& C0 @' ^
set-car-color
8 e! Y' A7 b* f2 y& g0 y" M record-data) Z7 L" P/ S# x' @3 f
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;; give the turtles an initial speed
# e1 E6 m# ?' o! ]$ n, p ask turtles [ set-car-speed ]' ^" X# l) A* d' J) Z5 @
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reset-ticks* `* i# G$ Q2 b
end. X) L$ S; e+ b
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;; Initialize the global variables to appropriate values. k( Z! T- a7 j8 R5 D
to setup-globals
2 z) D; F2 G4 E* L set current-light nobody ;; just for now, since there are no lights yet
' [, n. ~9 _9 }! U set phase 03 W+ c, i0 F$ o6 m
set num-cars-stopped 0
) v H; l, P) ]( L- h) X2 ?5 A$ E- m set grid-x-inc world-width / grid-size-x) `' p( v* h8 h F0 Q6 H) w
set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
! J! G, x! N. R u( W set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets, u5 q3 P1 ?8 j" C! Y
;; and initialize the traffic lights to one setting* w4 [6 E; I8 A1 h- i4 V# l
to setup-patches5 C$ S% @; K) G) N0 R6 ^# a
;; initialize the patch-owned variables and color the patches to a base-color* Y% e( R" q8 p% p6 S
ask patches
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set intersection? false
8 M/ k% K, z5 ^; V set auto? false7 s- T3 J! A, m+ m/ z2 J( }: b
set green-light-up? true# z& v* O2 H; e7 d" k# G) _; d7 c, P' `
set my-row -1
% `# z. n; _( X2 f# J) ^ set my-column -1
7 p* I+ r( k( M. j set my-phase -16 {9 i: P; ~7 S3 D& e% R0 l
set pcolor brown + 3! h3 m6 y# h8 H8 D
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;; initialize the global variables that hold patch agentsets2 B# Z8 m: Y0 f' k0 R* L% r
set roads patches with% W0 Q) T$ B+ x" t, {" k
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
) s8 ~" Y' L9 q4 q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 [- Y) f, A- y& [5 j3 q' i7 i' I
set intersections roads with
( p$ _' _* L7 x7 ^8 v [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and9 d8 a! v" A+ M
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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/ ]# r% I5 ]8 |3 m( W5 y ask roads [ set pcolor white ]/ n4 \ @" F% u4 ~3 D- }
setup-intersections/ A' L4 R% }% H* Y/ w G- N/ C
end- J$ Z. W9 Q# A2 F; y$ {
其中定义道路的句子,如下所示,是什么意思啊?7 L/ g7 U3 N( u$ o1 O* d
set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]) q6 S. C& E g$ Y- O
谁能帮我解释一下[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0)是什么意思吗? |
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