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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。' p! \' h5 \/ k+ ]8 n
netlogo自带的social science--traffic grid这一例子当中," W' s$ e ^ u" S" w7 K% ]
globals
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% }. [. o. k0 X7 z7 @ grid-x-inc ;; the amount of patches in between two roads in the x direction
- t: T. h7 }- B grid-y-inc ;; the amount of patches in between two roads in the y direction
7 m# N% Z! H- v6 Y acceleration ;; the constant that controls how much a car speeds up or slows down by if; n# O( L2 @$ m
;; it is to accelerate or decelerate5 ]$ `- E5 T7 I6 h
phase ;; keeps track of the phase2 z# Y2 N2 X7 g5 }; N4 V
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure) i& n9 ]; ~7 q/ N) w+ s
current-light ;; the currently selected light
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;; patch agentsets3 o" h3 s, J' V9 {: s
intersections ;; agentset containing the patches that are intersections
4 u7 x2 O, e1 E. \0 U- P$ R roads ;; agentset containing the patches that are roads& M. u+ i p- P6 @1 J+ B h
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turtles-own- [7 B! r8 ?+ q L2 v2 G& k3 O, k
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speed ;; the speed of the turtle
- u# d# R+ Y# C& n up-car? ;; true if the turtle moves downwards and false if it moves to the right
* s R! l* _; y1 O wait-time ;; the amount of time since the last time a turtle has moved
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patches-own3 \ A$ R" J. j9 ?) P
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intersection? ;; true if the patch is at the intersection of two roads
% M/ B0 Y: Z/ G, ~$ | green-light-up? ;; true if the green light is above the intersection. otherwise, false.. E8 I2 M# @7 n, b6 d* t
;; false for a non-intersection patches.+ O- G) Z+ K, {- D6 ?' \
my-row ;; the row of the intersection counting from the upper left corner of the
& c, H% F$ w7 O! A8 h6 E ;; world. -1 for non-intersection patches.4 M% x, a, U! C% d- O0 M" t, c: c
my-column ;; the column of the intersection counting from the upper left corner of the
5 b# @- H4 ^$ l! D ;; world. -1 for non-intersection patches.
) b- N {+ k' i K* R my-phase ;; the phase for the intersection. -1 for non-intersection patches.& s" X; ~ p2 `; s7 @! W7 y. H
auto? ;; whether or not this intersection will switch automatically.
( V6 l$ Z R* H4 R w ;; false for non-intersection patches. B# O1 y# j4 R5 C# Z" X9 P4 j
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;;;;;;;;;;;;;;;;;;;;;;
+ R; S, x8 t; l+ V3 G$ x;; Setup Procedures ;;
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% V: j1 w8 W; a8 d;; Initialize the display by giving the global and patch variables initial values.
1 [4 a2 Y |' \' ]6 w6 t;; Create num-cars of turtles if there are enough road patches for one turtle to
! O. D: W) q' W% g, u;; be created per road patch. Set up the plots.1 l: N/ Y+ `1 _
to setup
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setup-globals% d6 C1 m ?- D" A- g( ^
' X8 q0 R" t U! x* i5 W6 [ ;; First we ask the patches to draw themselves and set up a few variables9 f' n* D: [ m% W& W' H6 @# w
setup-patches
; \* C: e; F2 a& z5 t; V make-current one-of intersections
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set-default-shape turtles "car"9 D: V* m g, J5 h8 f6 t
! G" k6 w+ X$ w if (num-cars > count roads)' s6 C0 U I* X9 H, D
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) M. s8 K e: r/ I+ P+ ~ user-message (word "There are too many cars for the amount of "
! O7 C- D6 v# U! X* [ "road. Either increase the amount of roads "
! M" w. U: ]; @/ z) `2 r "by increasing the GRID-SIZE-X or "
+ y6 a' p# W) M "GRID-SIZE-Y sliders, or decrease the "
# q, S+ Z7 o# M2 ] "number of cars by lowering the NUMBER slider.\n"
3 Q6 v4 [. J: I8 ]) E; o "The setup has stopped.")( \4 N2 m* @0 Y( s* ], R
stop) S9 `! u9 r+ o( b
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7 _& [& b* T3 M& s; A ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color C# ]7 T! ?6 ]9 g+ y2 E' {
crt num-cars* ]/ E# m( U& p% `) h
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set-car-color
9 y8 u. W, ~; W: X3 ] record-data
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;; give the turtles an initial speed
* z/ d. Y9 |2 i- T( V: d7 E ask turtles [ set-car-speed ]
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reset-ticks
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+ T: o" F% K9 A1 };; Initialize the global variables to appropriate values
}9 X4 D+ N8 e. I& Jto setup-globals
; ]$ E; j5 x/ @+ T$ w% M& W2 N set current-light nobody ;; just for now, since there are no lights yet* C2 c! W# G$ |4 v
set phase 0$ o5 |7 }" [7 I+ w# p6 ^9 `
set num-cars-stopped 0
& i8 m+ k j1 ~9 J set grid-x-inc world-width / grid-size-x
0 U2 q) a, m- c+ C: J3 \ 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- \& Z. y# K8 _" X0 T- O- ^, X
set acceleration 0.0995 G* ]4 J; E: F7 l
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
; ^% L3 h% ^; U6 s;; and initialize the traffic lights to one setting0 x. N# _' Z1 G( z. f ?
to setup-patches" O# e. M& X9 z5 Q+ Y9 Y
;; initialize the patch-owned variables and color the patches to a base-color& z4 ~$ d d9 Z0 @+ m+ q8 u; \
ask patches+ i. m! B% C" K3 O2 n
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set intersection? false8 W% X: D; A/ k1 q0 L* [8 @' w; D
set auto? false
+ @- N9 f0 k: h, R1 N* R! w set green-light-up? true* v* [- E3 g* @9 J; T
set my-row -1
# s& i* q4 r. X& F1 f$ |7 u set my-column -1; ~4 t E. z( K% O
set my-phase -1
; [2 [* h# q# i; |( F, t0 c, B set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets. P3 ~8 H, E0 ]0 y( e! G( D
set roads patches with6 C4 I S& p. r J
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
, m% n5 a8 B9 f (floor((pycor + max-pycor) mod grid-y-inc) = 0)]# E: c4 q: m% K; e
set intersections roads with
5 T2 r: p& v c! J3 r+ G, p: D% ` [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and2 d1 t0 t! _. R( l1 p' l
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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* q5 \* o. D& j. x, W+ V, ] ask roads [ set pcolor white ]
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end9 K0 K( A" U8 I" h3 k- P! g C' f
其中定义道路的句子,如下所示,是什么意思啊?
% z. Z+ p! i' d' c9 G- h set roads patches with& |3 U- Y- q3 m" I" j
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 v* i3 T9 v1 D# C/ u
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
+ o6 r( O n t% 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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