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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。9 U8 m% A; g- O) z, o$ g9 Z3 |
netlogo自带的social science--traffic grid这一例子当中,
! f$ C3 s* x4 \) N' a$ E' S! a1 c. A- Gglobals
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9 b6 n- O# f6 f& d8 K3 ~ grid-x-inc ;; the amount of patches in between two roads in the x direction. A. _8 l A; U* x
grid-y-inc ;; the amount of patches in between two roads in the y direction
: F! w) H& x4 _: _6 t acceleration ;; the constant that controls how much a car speeds up or slows down by if
5 P. }! n, ]; m' S' | ;; it is to accelerate or decelerate; N! h Z+ @; P
phase ;; keeps track of the phase3 k! k9 `4 A4 {# H7 i
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
' G2 Y+ a/ {& B current-light ;; the currently selected light' |, k. C+ y, F% Q* d* p7 G% ?5 G
@" B/ V6 e D1 t ;; patch agentsets4 m7 ]0 K% D4 n. N% A& r& [
intersections ;; agentset containing the patches that are intersections
( N @) Q Y& _3 I- n& p roads ;; agentset containing the patches that are roads
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turtles-own
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5 \$ ?& W: p- m( p& Q speed ;; the speed of the turtle
7 S- |: ?0 h( b$ P% u4 Q up-car? ;; true if the turtle moves downwards and false if it moves to the right- j- w) h: E2 M% i
wait-time ;; the amount of time since the last time a turtle has moved1 K* I( X8 s9 e6 g) u T( C0 q% n. d
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads) p3 ^9 ~( n8 [$ G6 A( p, ^
green-light-up? ;; true if the green light is above the intersection. otherwise, false.& N9 y0 Q; f$ G& O- L
;; false for a non-intersection patches.7 E7 h- B2 Z5 a9 I
my-row ;; the row of the intersection counting from the upper left corner of the
# b9 P8 b: q8 c ;; world. -1 for non-intersection patches.
8 b/ c; j( }0 f3 C. ]1 H my-column ;; the column of the intersection counting from the upper left corner of the
! d% j6 X- v) O2 w! D! s2 |4 p ;; world. -1 for non-intersection patches.
$ |! ~1 s8 C! `6 J; B my-phase ;; the phase for the intersection. -1 for non-intersection patches.
9 |% R8 f8 m: H+ D9 s auto? ;; whether or not this intersection will switch automatically.
2 j4 [" M) o+ a! `: c6 q ;; false for non-intersection patches.9 M1 g( X2 b) s+ ]$ N
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;;;;;;;;;;;;;;;;;;;;;;
; j4 r0 x& k' B# a) V* W; a+ w: x;; Setup Procedures ;;
/ B$ t' l1 f9 ^ U: q+ L- e& Q;;;;;;;;;;;;;;;;;;;;;;
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! ^; F: O- o/ f# N& j4 z;; Initialize the display by giving the global and patch variables initial values./ R: W9 J" ^8 Y% T* R! N+ x
;; Create num-cars of turtles if there are enough road patches for one turtle to7 a3 \: H) a* `* x
;; be created per road patch. Set up the plots.! M; A: g8 c/ Z! k8 \. t
to setup
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setup-globals3 m0 F* y8 K" F' T% e B
# S$ \+ @) H' d; G% O ;; First we ask the patches to draw themselves and set up a few variables3 K3 H6 l+ k+ c4 d
setup-patches
8 a2 u* B% x! x- Z: m# @& G make-current one-of intersections
9 n$ l3 G- K9 j( | label-current' s3 P1 n4 s8 g6 `
( y9 J! w6 X7 Z/ F4 X U set-default-shape turtles "car"
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if (num-cars > count roads)
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% V0 e5 |* w, W( J+ g' l3 u7 S% h user-message (word "There are too many cars for the amount of "
+ ?7 v7 Q! }) v9 r, U, e/ O! I "road. Either increase the amount of roads "
* B9 @) e/ t# A4 `' | "by increasing the GRID-SIZE-X or "
: c+ B S* g! S) O- U/ { "GRID-SIZE-Y sliders, or decrease the "6 L: R$ Y+ A' z8 ~3 _/ _& V# R0 T. M
"number of cars by lowering the NUMBER slider.\n"8 U7 k/ o- o% [+ G% T) n: v1 Y
"The setup has stopped.")' \! o h+ P) e2 a( L5 G9 n0 T( m
stop
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: ?$ [: K3 v8 `/ e ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
5 Q8 F+ H- U# T5 ~ crt num-cars
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setup-cars
7 z: Q+ ^: {' ^) y/ V set-car-color9 _ V; @# ~: S6 P
record-data
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;; give the turtles an initial speed: A; i& @4 B; K5 z% P) t
ask turtles [ set-car-speed ]
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7 V* Y* _( D& Q- N+ z5 r2 J reset-ticks2 |) f N: D; ]
end Z6 a/ c0 n/ w
/ p! D4 Q4 \: M, Y \& S;; Initialize the global variables to appropriate values
, [ P/ s/ h5 S0 [4 ~4 h! [1 ato setup-globals
9 ~- w7 E' t* X$ S& m2 S set current-light nobody ;; just for now, since there are no lights yet/ t5 R7 Z( ^) X
set phase 02 x: v; ?. D. S( h, e- X
set num-cars-stopped 0
4 O1 J% D* V {( P set grid-x-inc world-width / grid-size-x2 ?' K) x4 q5 G2 M& }/ J
set grid-y-inc world-height / grid-size-y* m5 K3 h* {; ^/ g: h+ i7 {7 g
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary# v# l7 i2 A3 h; r
set acceleration 0.099% B2 v& { X9 _" \
end
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' h& `" D; s- [7 N8 p' g7 };; Make the patches have appropriate colors, set up the roads and intersections agentsets,
; c' i) ]: o2 l9 H;; and initialize the traffic lights to one setting
9 v, h; ] n/ U8 Gto setup-patches
- |+ C) ?! j. B, O+ o ;; initialize the patch-owned variables and color the patches to a base-color; L( b2 w* E& e. q- k! @4 ]& s
ask patches
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, H( `0 k$ k: V7 Y, t; | set intersection? false
' n3 R! k; Z: H" b' l, z# ~ set auto? false% L. ^9 L" o; ~# W8 ?, I
set green-light-up? true
T8 G; i, P6 E% h" B set my-row -1
+ E' R! o: R$ t2 I8 A1 X9 k# { set my-column -1
# q) h3 s+ J4 f. p! U- e1 z/ ^ set my-phase -19 t5 \+ T c1 L2 f9 X' {* X
set pcolor brown + 3
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, E; B9 h" r% |5 V ;; initialize the global variables that hold patch agentsets
8 |1 a6 i5 \* ?) F: X set roads patches with" N1 W! O+ k/ _. c( o
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or* o) m, G. S. g: y" v
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 r) `# `9 X% s5 F$ `- Q
set intersections roads with
* E( l3 p" R+ |/ m1 O+ J" t [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and4 C* R2 u" q! | H' g& s
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]1 x8 @7 _6 ^8 E% P5 M
setup-intersections9 J; o. C( m! t- X; p: t( ^. Z
end
1 k5 X8 h( Z: Q1 q& v其中定义道路的句子,如下所示,是什么意思啊?
) B. P- m! Y4 T8 L( {4 A set roads patches with
. D! Z- G1 E0 T6 _3 n [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: Q' f' W( D: y: { (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: t2 Z. x. ^2 m; Q* _ j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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