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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。
* `0 D: r) {) r; ]1 O! ^netlogo自带的social science--traffic grid这一例子当中,9 }5 G# c8 L* }
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
* N2 n3 ?8 k4 I( C& z8 C grid-y-inc ;; the amount of patches in between two roads in the y direction
6 v8 m& ?+ `4 q2 ^9 _ acceleration ;; the constant that controls how much a car speeds up or slows down by if. j, `4 u$ |1 F* c# z
;; it is to accelerate or decelerate) y w2 @6 f# z1 i! F" x
phase ;; keeps track of the phase
7 W# B) `1 {4 z! W" Z1 e! D/ z num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure* a7 T/ ~3 R) a* j$ c8 y, g- Q' U
current-light ;; the currently selected light2 ~2 r' a$ x7 Z
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;; patch agentsets
0 T& g7 ]0 t& t6 j& {; d8 J intersections ;; agentset containing the patches that are intersections! `5 B5 i4 |/ v6 R6 P5 l2 K
roads ;; agentset containing the patches that are roads
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turtles-own9 M9 P7 n) q& j" \" j4 S
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speed ;; the speed of the turtle- K2 i/ y! O! p9 r2 t4 M4 U6 B
up-car? ;; true if the turtle moves downwards and false if it moves to the right
* D* e5 e! @8 r w/ x+ U8 @ wait-time ;; the amount of time since the last time a turtle has moved& \7 } [: Q/ g* @7 [, L* ?
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! Y3 Q/ X( D0 {( T1 b) Vpatches-own
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8 k0 w8 Z8 R# ^ intersection? ;; true if the patch is at the intersection of two roads
" q7 ^ Q* Y/ J, b& X# @ green-light-up? ;; true if the green light is above the intersection. otherwise, false.
7 f& P% e) j, Q" w+ {. Q3 ` ;; false for a non-intersection patches.
. y/ l! n! [! t+ Y3 @3 V/ u2 e my-row ;; the row of the intersection counting from the upper left corner of the0 y# m8 u4 a1 y$ H- E1 z0 U
;; world. -1 for non-intersection patches.
' T% ]! B! b2 n, k7 f my-column ;; the column of the intersection counting from the upper left corner of the5 z3 U. k- s) M1 M7 L( V- K
;; world. -1 for non-intersection patches.% K! h% v0 a# Z( U8 g
my-phase ;; the phase for the intersection. -1 for non-intersection patches., i7 K2 n$ }; N& u q5 q( ^
auto? ;; whether or not this intersection will switch automatically.
/ C/ N2 N' |3 y* X: n ;; false for non-intersection patches.# s8 J8 z8 E$ p" B) J' u) P
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;;;;;;;;;;;;;;;;;;;;;;
" r8 U L8 P7 `% a* Z1 [8 q;; Setup Procedures ;;+ H6 \, R; \9 D- B
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
m# l+ z. z) n% I. l' G. b;; Create num-cars of turtles if there are enough road patches for one turtle to
% J2 @4 u2 ~0 c1 @$ Y7 f;; be created per road patch. Set up the plots.$ b) [ n( D; g+ k& g% H3 `
to setup
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setup-globals' b D6 y# u3 f# I6 ]- ]
$ {- c& Q7 _5 K$ G8 k- u ;; First we ask the patches to draw themselves and set up a few variables
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make-current one-of intersections
% A; L3 S' v8 c label-current
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set-default-shape turtles "car"- U! F) ]. t2 k3 R/ p
4 X" c8 i/ j& H& o& v: [1 m if (num-cars > count roads); g$ ]' s' _2 B: ^; {
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user-message (word "There are too many cars for the amount of "$ u' U, A3 d$ @. |* ]1 O
"road. Either increase the amount of roads "" B+ @9 x! j# v' P( f
"by increasing the GRID-SIZE-X or "4 D2 p' o# m/ N8 R4 H: }) D# ` r
"GRID-SIZE-Y sliders, or decrease the "1 l, Z" c( H# M+ P8 |
"number of cars by lowering the NUMBER slider.\n", H2 x: C* G( W* f3 P/ c
"The setup has stopped.")
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color7 g1 y2 x6 [5 A8 k( H8 R2 q
crt num-cars
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setup-cars
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record-data+ _9 ^" \9 ]/ n& m- D
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;; give the turtles an initial speed
* ~' h# t% o+ @+ T) Y k; F1 b% c ask turtles [ set-car-speed ]5 @3 F8 {2 I1 b" Z r
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reset-ticks
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;; Initialize the global variables to appropriate values
+ x) ?5 [+ C0 Gto setup-globals5 g7 Z9 T/ P5 S! \6 v9 N( q% z
set current-light nobody ;; just for now, since there are no lights yet
. N$ t W* T% L J n0 u set phase 09 J) U1 Z, O1 I1 ~8 y- T* @
set num-cars-stopped 0
+ a6 [: V. k- E) _. y( B set grid-x-inc world-width / grid-size-x/ H$ S7 d3 S( o+ p* j: ^5 @* I
set grid-y-inc world-height / grid-size-y7 t! C. V, M* i0 f# e
3 G3 | D3 Z9 g ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
) G u D% H6 K2 K set acceleration 0.099
" N- v' ~6 G6 s4 T5 G, t9 A# {end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,+ A( `% ^9 g( ^0 [
;; and initialize the traffic lights to one setting! O& d J/ a' m X
to setup-patches# a) e8 {! S! _& U r: k
;; initialize the patch-owned variables and color the patches to a base-color
) o- U& _% E9 x ask patches' p8 {; I3 M7 d; ^
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set intersection? false
( \! K1 c, i* u# q5 Q set auto? false+ w( q3 ?; L8 y+ Z! e+ [2 a- B
set green-light-up? true
9 @; s6 `7 R8 R0 c& s. k) a! O2 ` set my-row -11 F* j: f2 I$ N6 z o
set my-column -1# q0 R6 F' o/ R$ R! v
set my-phase -1
) N' ~5 U7 f1 S; a) I8 |6 R) H( R set pcolor brown + 3% g/ q" r9 T: @7 g
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;; initialize the global variables that hold patch agentsets9 e$ I" X2 ~- M' F1 [3 |; S
set roads patches with
/ G* B+ k4 o3 c% q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or6 U O* d" U9 d4 ?- }
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% z' @8 P! Z- \; T- J set intersections roads with: `% \" T3 E8 E( U+ z" k
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and" \0 z( y$ m- G4 \& h! s/ W
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 d8 z( n' l) r6 J) t; Z
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ask roads [ set pcolor white ]2 X- E' M" D# f7 {" @5 N
setup-intersections
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/ ?+ ~. L5 [) l% z1 }# j: Z其中定义道路的句子,如下所示,是什么意思啊?6 ?1 O1 g/ v3 g4 v6 G6 F
set roads patches with
D& u4 j* i8 C$ b! @% p [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or# A0 b) k# T* |) S
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) H; u4 E2 }% {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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