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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。% a: U5 E, Y1 t+ u1 }' [# a
netlogo自带的social science--traffic grid这一例子当中,& ]) `8 h. }% Z) z X1 t) H
globals
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9 L- N& G7 D) y grid-x-inc ;; the amount of patches in between two roads in the x direction
" [+ A+ N. v+ h5 _ s+ D! } grid-y-inc ;; the amount of patches in between two roads in the y direction
3 k" X* w3 G5 Y, ]/ N. d acceleration ;; the constant that controls how much a car speeds up or slows down by if
% z% a- G6 p% ~% [4 i3 Y ;; it is to accelerate or decelerate+ A+ V$ A' u0 V
phase ;; keeps track of the phase# I: T4 s! T! a7 k8 S9 P( _+ Q
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure* T- f4 N1 ~% f* o8 z
current-light ;; the currently selected light
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;; patch agentsets
: b7 f2 i( p" [$ H9 | intersections ;; agentset containing the patches that are intersections
" ?6 W/ d0 x" | roads ;; agentset containing the patches that are roads
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8 }, _+ c3 H+ M+ ]2 i. l) @$ cturtles-own
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; X6 ]* X! ^; k speed ;; the speed of the turtle
9 n; d y/ j5 Y" }+ | up-car? ;; true if the turtle moves downwards and false if it moves to the right! S6 g% C" ?9 z1 }. K
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own1 v, B5 v3 s* |3 e" N1 b3 V) b
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1 C/ R, {3 s. [ intersection? ;; true if the patch is at the intersection of two roads8 d; V# z% F; X4 E* Q2 ~
green-light-up? ;; true if the green light is above the intersection. otherwise, false.& F" V0 \/ K1 E" Z6 _" O. Z5 ?
;; false for a non-intersection patches.2 ?2 E! I1 n y/ D( N% y
my-row ;; the row of the intersection counting from the upper left corner of the
6 x$ x9 m) }* l0 u4 {1 ?4 e ;; world. -1 for non-intersection patches.
& a; i- w" T5 Q, T2 f9 g my-column ;; the column of the intersection counting from the upper left corner of the
0 Z. S* p" s( G# { ;; world. -1 for non-intersection patches.
4 x$ @. z" \& {' `6 [ my-phase ;; the phase for the intersection. -1 for non-intersection patches.
+ s" S5 X* ~4 P* Q; o/ `# \ auto? ;; whether or not this intersection will switch automatically.& x( j& M9 a. Q# P
;; false for non-intersection patches.8 p% Y* i8 H) B% t
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5 G0 d% N& v; l) K;;;;;;;;;;;;;;;;;;;;;;$ Y2 P; u7 i1 k$ x/ \$ {5 t; z
;; Setup Procedures ;;" u' B# w( ]8 c7 J ~, c- H9 i
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;; Initialize the display by giving the global and patch variables initial values.% o$ D+ P$ Y7 g3 _
;; Create num-cars of turtles if there are enough road patches for one turtle to
( m% ]3 H" C" X;; be created per road patch. Set up the plots.
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setup-globals
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: ^; P/ k5 C+ n! |& V! I' i ;; First we ask the patches to draw themselves and set up a few variables' A& x$ [& z/ U2 F3 @
setup-patches
# A& E0 I- j' O. E! s# Y7 j- N make-current one-of intersections
- F4 b1 P k4 r& E label-current* A4 @" |1 m$ w U5 g
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set-default-shape turtles "car"$ B- g5 ]$ y6 I- ^* c& T
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if (num-cars > count roads)
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; j6 W3 G3 P( j. a1 g user-message (word "There are too many cars for the amount of " U, }+ u7 Z: G9 Z) m% g& `
"road. Either increase the amount of roads "
i' c, @ x0 C+ _# [ "by increasing the GRID-SIZE-X or "
( G7 L/ I+ |8 x$ K6 M "GRID-SIZE-Y sliders, or decrease the "
7 B, p2 R+ l+ x) f; L! W "number of cars by lowering the NUMBER slider.\n"; ~1 k3 _# U( t. e
"The setup has stopped.")! S7 L0 o! l4 Z1 Z
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
; }$ e: L; E7 q/ k crt num-cars' m% M+ V! m' i! p5 W
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2 t- n! K0 c) a/ R* W+ ^ setup-cars; N- L2 v5 J/ w4 ~
set-car-color- }* y9 S. m" H& h6 M
record-data Y, f8 E6 X7 B( k; r) U5 y- e, a
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0 A! h6 @: V! c( }4 X! t! E ;; give the turtles an initial speed3 ~# ^; B) g$ v8 P- P( z" g2 s
ask turtles [ set-car-speed ]
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( _# g6 [8 ?9 u" W! W+ l* X reset-ticks
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" F. j& @$ T1 P3 j1 E" I;; Initialize the global variables to appropriate values
7 `+ ~4 J0 u/ g- p7 Rto setup-globals
6 r' G% o# o& @2 k" h( j* P T set current-light nobody ;; just for now, since there are no lights yet# F/ K. D9 K' z+ e% V, g- B1 g- S
set phase 0
9 t8 U2 M1 X8 ^; w set num-cars-stopped 0+ o. b& L: h2 c }0 }
set grid-x-inc world-width / grid-size-x& A1 N3 O/ Q" m' c
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 boundary8 ?$ e8 ^) B; L: j; E; g
set acceleration 0.099
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4 N* o) c: V) c1 P4 ~;; Make the patches have appropriate colors, set up the roads and intersections agentsets,7 ?4 E' R/ t0 e; Z6 }: j6 v3 q
;; and initialize the traffic lights to one setting
+ u! D5 w: h3 R' T7 H7 Ato setup-patches
3 F+ `* f1 }8 Y! p ;; initialize the patch-owned variables and color the patches to a base-color: J9 }9 [3 s, u) b
ask patches
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set intersection? false5 E# N) d* o4 ]& T
set auto? false
" {+ M4 Y% [( k$ d9 R$ T set green-light-up? true
8 [7 m9 P/ y6 t |1 e2 r set my-row -1
% X& c! Y, G! C* q) g set my-column -1. T( [; l7 P- W& ?
set my-phase -1
; l2 K9 n- U8 V" v; v; u0 l; d set pcolor brown + 3! @- Y% e7 v- y' M7 r7 Q! A) f
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;; initialize the global variables that hold patch agentsets
- Q: b- p4 k& x set roads patches with/ G( w1 M5 f% Y; e# }4 c0 `" U
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or. d8 F4 T0 p ]5 g% Y" o' Q
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 ~! ~# w0 e2 K
set intersections roads with2 {! a! R4 s% v4 k' a+ s1 n- l
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
7 L" f, w6 h8 V; O6 t: E (floor((pycor + max-pycor) mod grid-y-inc) = 0)]. V5 s' ?8 g0 o- J& u/ L1 m' p3 ?
% E% j( j7 @3 ^5 m- W; i ask roads [ set pcolor white ]; {* b5 O; J8 J: S- j! F; o4 `
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?+ a& _, K* i2 ^5 U) L# H4 Q
set roads patches with
( H( \$ a( g" E) A. [ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or( B$ ^6 c# S, w1 C0 a1 d$ F
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 B2 z0 p6 Q& b( Q( p+ W
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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