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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。; L- o/ ^* `/ @
netlogo自带的social science--traffic grid这一例子当中,
! z- N& P. y. _ n1 k; F& eglobals
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5 P6 K2 M, S, F1 U2 i; v. k grid-x-inc ;; the amount of patches in between two roads in the x direction: O9 L7 ]# |+ s2 [) A
grid-y-inc ;; the amount of patches in between two roads in the y direction
9 B* H! L. @! G6 G' G acceleration ;; the constant that controls how much a car speeds up or slows down by if4 x) p" b8 x( e
;; it is to accelerate or decelerate
# R9 w& G' w. r! J phase ;; keeps track of the phase2 ]2 o; H C6 J. F
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure ^( |/ j. V e: _2 a, _; e
current-light ;; the currently selected light
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/ C2 }% B* `0 U& M$ N ;; patch agentsets
' l# U0 ^* {' @3 ^ H% U# } intersections ;; agentset containing the patches that are intersections# u" @: F* P7 z% W
roads ;; agentset containing the patches that are roads+ m0 c$ v9 v4 t4 \: Z( z
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turtles-own
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speed ;; the speed of the turtle& v# `1 J/ e3 c5 x3 \3 a
up-car? ;; true if the turtle moves downwards and false if it moves to the right
* |: M$ z' _6 `# N# U wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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" e1 Q0 L% V8 E& k intersection? ;; true if the patch is at the intersection of two roads
2 K7 L8 E# a# o! X5 A# c4 J: o$ f green-light-up? ;; true if the green light is above the intersection. otherwise, false.
8 s* v0 \$ ^- L8 E ;; false for a non-intersection patches.0 \8 ]3 j. d3 D% r
my-row ;; the row of the intersection counting from the upper left corner of the, K* v5 m/ `- O3 A% }
;; world. -1 for non-intersection patches.
2 z J7 O- t7 i/ F% p/ t my-column ;; the column of the intersection counting from the upper left corner of the
7 u& Z/ M. f' `2 z7 x ;; world. -1 for non-intersection patches.7 P" e% `- u6 k3 V% S" b2 o k) n
my-phase ;; the phase for the intersection. -1 for non-intersection patches., t! b) v) }0 E# v" f9 N
auto? ;; whether or not this intersection will switch automatically.! F0 h& I. b3 S% j
;; false for non-intersection patches.( Y( e2 M$ ~2 _8 Z/ [
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D- I {: E1 ?. l;;;;;;;;;;;;;;;;;;;;;;$ _" V, a8 i; O% h. R& ]/ L$ R
;; Setup Procedures ;;( T$ `) P$ K; h4 h1 _4 K, C
;;;;;;;;;;;;;;;;;;;;;;
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' h }/ ^- P+ i- x6 c; b;; Initialize the display by giving the global and patch variables initial values.
, \) N: X/ l) m# R* i) E;; Create num-cars of turtles if there are enough road patches for one turtle to
0 _9 U2 J- d4 a;; be created per road patch. Set up the plots.% s' o# ~% l7 k. B r' ~
to setup
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setup-globals/ B7 |. M; p: m$ i
1 ~, m- i# D; n, @ ;; First we ask the patches to draw themselves and set up a few variables
( Y* m. [5 }+ `7 u, A setup-patches+ r! R; `' b A8 q, L% G2 H
make-current one-of intersections
; l+ d' b+ G* y# L$ @9 k label-current; C& E2 R5 b- b3 B; P
7 P9 d' u8 l0 D. S1 q" \ set-default-shape turtles "car"
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% A% M% I8 }6 g1 N) t( X, L if (num-cars > count roads)7 ]6 b0 _+ V0 e
[
( g. O* R6 U# c Y. ] user-message (word "There are too many cars for the amount of "
6 @3 T! Y6 g9 T U& z! \ "road. Either increase the amount of roads "" ?7 D4 T5 Y# b
"by increasing the GRID-SIZE-X or "
8 }! N9 c- V2 M* c "GRID-SIZE-Y sliders, or decrease the "
: Y1 B0 T; ~( M, `0 f "number of cars by lowering the NUMBER slider.\n"
8 ?* {! y! ?7 K+ p1 {$ U "The setup has stopped.")2 Z) ~2 E2 x* c1 X. l$ N
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
/ B/ Z& H2 e# `. Y7 A crt num-cars4 I- E& T) |$ J6 f6 u; L- k
[
6 E0 [: ]6 `7 V setup-cars6 [& U2 m* \5 r1 G+ m' t
set-car-color
* `/ A4 P( M# A/ l/ o; Z record-data3 j! C2 W/ U% j- s$ [/ E9 H
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) K' ~" W6 W* }1 _2 R" m- f ;; give the turtles an initial speed- {# |7 Z0 t3 o3 a9 ~. O
ask turtles [ set-car-speed ]$ |# m+ { @: l/ ]0 ~9 }
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reset-ticks
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;; Initialize the global variables to appropriate values
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; u) n! A9 Q7 t set current-light nobody ;; just for now, since there are no lights yet; X- g3 \4 C1 w3 w, c: W
set phase 0 E& E6 v' I0 |" o" I. ?
set num-cars-stopped 0( _. m. w( n' |+ S0 ] o y
set grid-x-inc world-width / grid-size-x$ {" n3 T% g9 @$ @1 ^( F1 w
set grid-y-inc world-height / grid-size-y
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$ j9 D+ m+ i. W ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary0 W3 h: c9 B- }4 S8 v# F' ~' O& G i
set acceleration 0.0997 c7 c) a. q: S5 z7 P n
end( r6 _, t) ~7 N. D& ^$ `, Y
3 M0 a- `7 B( I/ V4 a2 {3 r;; Make the patches have appropriate colors, set up the roads and intersections agentsets,0 b/ C& G3 i# x
;; and initialize the traffic lights to one setting' D" Z1 A C5 A* Q" D7 M1 i
to setup-patches
" L1 s& @* }6 e2 x. c5 i& ?8 E ;; initialize the patch-owned variables and color the patches to a base-color
* C D) L0 S4 w2 N ask patches# D) [! ^/ ?! l& F( P
[
( h6 v. s2 t$ y' u set intersection? false
`' z+ D0 ?2 T, V% L( c( K set auto? false
# i+ t; h2 K8 [ set green-light-up? true8 B+ Z; w# y" {6 H3 o3 C9 \% t
set my-row -1
3 y* ]. ?$ v! @ H set my-column -1) h" j& e# j) G* J$ d
set my-phase -1" W' o0 s4 e. M
set pcolor brown + 30 E% _6 q3 L& u0 V3 U/ n9 N# U
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;; initialize the global variables that hold patch agentsets
$ `+ ^2 j1 E2 J H% ]$ x4 T- s+ j$ M set roads patches with
3 w3 I' O; C/ o2 ~, M# N [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" \) b( m0 Z1 {1 E4 D (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
- r9 y/ x. c+ B: M set intersections roads with
8 j7 }7 L% x! _3 U R [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and J6 |( u% A) k4 \
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
! {$ C9 [' r1 {$ n( A \ setup-intersections
0 {9 L8 o& ?4 |% x, uend
8 n9 ?8 c6 ?9 M* v2 Z. t9 s3 Y7 l其中定义道路的句子,如下所示,是什么意思啊?
. l5 {3 F: {* o( [ set roads patches with! `6 Q3 x w8 Q# T3 S! f
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) p5 q, h r+ Y$ T6 I& R
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" i- Z5 }% ]0 h2 j# M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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