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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。
6 f7 D+ J: F R2 bnetlogo自带的social science--traffic grid这一例子当中,
* ]( ~% `& g+ Z( f2 e. [globals( w& ~; ?6 B+ r9 X$ A
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grid-x-inc ;; the amount of patches in between two roads in the x direction
3 D' I# `; B0 `/ D" v9 o grid-y-inc ;; the amount of patches in between two roads in the y direction6 J1 P9 W% q; s
acceleration ;; the constant that controls how much a car speeds up or slows down by if1 d& U [2 u# Y# x
;; it is to accelerate or decelerate
$ w7 q: M- i. R) X4 E phase ;; keeps track of the phase
: x8 ?0 ?3 s8 C2 p' o, H8 S. i$ Z num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
% Y0 t# L g+ R) e current-light ;; the currently selected light
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! G5 T. ]* @$ M( t3 g( J& y ;; patch agentsets, G W9 Y" n( u. F. j/ a1 P
intersections ;; agentset containing the patches that are intersections
7 a5 X a2 t! |# R) y0 w" X3 `" ]. ^ roads ;; agentset containing the patches that are roads: V# ?) k/ p* f6 T& R
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$ b4 Q: t. A7 Yturtles-own
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^/ L6 |2 V/ Q7 i speed ;; the speed of the turtle
6 g0 {" Q* D- L- W L up-car? ;; true if the turtle moves downwards and false if it moves to the right3 y3 v" W) }1 L$ i" h0 j+ C9 c
wait-time ;; the amount of time since the last time a turtle has moved O( W' U: q$ P" n# b) X
]
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patches-own: a6 r0 X$ G/ _, V
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intersection? ;; true if the patch is at the intersection of two roads
, h4 p1 L. U3 i green-light-up? ;; true if the green light is above the intersection. otherwise, false.
" f0 E1 ~& v0 o/ t1 ~! y1 I ;; false for a non-intersection patches.6 V& S/ A4 ]0 S
my-row ;; the row of the intersection counting from the upper left corner of the
( ~) I" O8 [7 ^. l$ O: I5 O ;; world. -1 for non-intersection patches.# v$ A" F9 e, F) o* g% f
my-column ;; the column of the intersection counting from the upper left corner of the
0 f% h8 q& @! X+ i6 q ;; world. -1 for non-intersection patches.
7 v" }/ Y& R: }8 t" x* a my-phase ;; the phase for the intersection. -1 for non-intersection patches.
9 c9 j7 f. e' U8 j- {0 C i auto? ;; whether or not this intersection will switch automatically.
$ g* j# I* U9 P; i1 R A, E; g ;; false for non-intersection patches.
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; N- v/ z1 C7 L$ s u4 P;;;;;;;;;;;;;;;;;;;;;;
$ Z7 _% x I9 f" j# n! C4 l;; Setup Procedures ;;4 B$ O+ z( Y# V8 I' C' [$ S0 w
;;;;;;;;;;;;;;;;;;;;;;
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1 {: j- n5 Y9 d$ F;; Initialize the display by giving the global and patch variables initial values.
# y6 V, ]) I4 Y) R0 S" w m! G2 V;; Create num-cars of turtles if there are enough road patches for one turtle to+ Z( x) \) J5 i5 {6 y
;; be created per road patch. Set up the plots.$ W2 t: E. S: r( r7 w# v
to setup
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setup-globals; T; K- j6 w, z
) m! e6 w% ?. g3 @; G ;; First we ask the patches to draw themselves and set up a few variables
- N6 X+ \* p$ x setup-patches
3 r+ M, H7 W" m9 O s* x make-current one-of intersections
- t; K/ E& _$ t& P+ ? k& r label-current
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set-default-shape turtles "car"
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, Q) \9 P1 }" i. T2 n, S* t( L6 h) f if (num-cars > count roads): _$ B4 Z7 B% v6 x1 y
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user-message (word "There are too many cars for the amount of "
9 n( o$ j* c' \4 j! M' j1 ^2 f9 W- x "road. Either increase the amount of roads "6 H: C+ P/ a; c9 W4 j# |, _+ `
"by increasing the GRID-SIZE-X or "
- O; Y9 K. u6 l! e. c% N4 [$ \ "GRID-SIZE-Y sliders, or decrease the "
! H" H& K L+ S! t( I "number of cars by lowering the NUMBER slider.\n"
8 O3 i) K- L5 F "The setup has stopped.") A( p+ W- T1 r2 q# h' G
stop2 w$ m. @! B+ Y i. G
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- j7 C4 j( ?2 y9 n" C/ x ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color# E! ^! J1 n; @ O; ~) }" a9 X
crt num-cars/ k/ E) S+ x4 p
[
7 Y4 J0 u: n7 |1 [/ G2 N setup-cars
* r5 \2 P* @. a) i set-car-color
! ~0 R/ t; Y3 d% J9 Y record-data
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;; give the turtles an initial speed1 O! a% P" P4 l$ r; t" y1 P
ask turtles [ set-car-speed ]
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reset-ticks) p3 r8 H8 C" D5 d( v8 L& G# {0 p3 f
end4 H$ i1 w9 h) \ n0 L* W1 {" @- n
' q& @ B/ F9 G! b;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
s. p- ^4 _& l5 Z3 k set phase 0
' r8 i8 }! a; Z9 g" t: q/ E set num-cars-stopped 0: r! m. n4 F* q8 r! I$ E T
set grid-x-inc world-width / grid-size-x T$ c& @% s# V. y# h6 S
set grid-y-inc world-height / grid-size-y6 E* r. r% x& V4 d l4 ?7 w g
$ b6 S! Y r" y# Y8 [# N0 g8 H ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
- m$ [4 u/ a [, H" C" L v+ g set acceleration 0.099
$ v% O; ]! [* V) p) ]! e( Lend4 I, g; v- o$ P# A7 N: p/ d
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,( |# D1 V! ~1 d3 z+ ~0 j0 r
;; and initialize the traffic lights to one setting/ Q4 G6 e/ `2 @. D
to setup-patches# C& x2 l* r6 g3 j
;; initialize the patch-owned variables and color the patches to a base-color
/ ~2 r8 i; i/ B( t ask patches
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set intersection? false
5 y4 H: [* C' Q3 W# K: E# F set auto? false3 _) `: z% E/ j* U+ ?" o/ d; ~
set green-light-up? true
/ i; D8 W& J/ q, r3 @ set my-row -1& p7 u: J* E/ L! b
set my-column -1
+ b" }, m- n% A f. ^ set my-phase -1
( z. |) s9 Z1 D$ C& w' o0 Y, h# T! R set pcolor brown + 3
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* s0 Y! V( o) t+ _! Z7 G4 |. s ;; initialize the global variables that hold patch agentsets
/ r% L3 s" X. e) f set roads patches with+ T) z: Y: ~* q- Z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 N& G, L# Y' z* } (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" w9 x; P+ Q# K3 _ set intersections roads with4 t/ Q. A( J% c% v0 ?
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and3 y/ V0 Y1 ^. n+ m% H1 A/ _+ Z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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' G4 a% w8 L# D! I7 x- n ask roads [ set pcolor white ]
d9 K' B: \4 P setup-intersections P6 A/ k( e& m0 z' d) i! b
end
8 d, W2 @' d! N d0 A其中定义道路的句子,如下所示,是什么意思啊?2 l+ Q @3 k1 p D/ ]
set roads patches with! j x1 O' p; G9 P5 `4 V. n7 H* r
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! {( `" q, k# ? (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 Y# \; k7 l4 w* u$ N+ N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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