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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 H/ O8 k. r% n+ y9 O2 m- Xnetlogo自带的social science--traffic grid这一例子当中,
9 ~$ I& y& |0 E+ H' d( f/ oglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction( J$ u7 ?" `* T) V
grid-y-inc ;; the amount of patches in between two roads in the y direction
* w% `8 a& |" h2 J acceleration ;; the constant that controls how much a car speeds up or slows down by if
3 p) \( s( m5 h( K7 g+ b ;; it is to accelerate or decelerate
b) b" q% w x) x8 ~( [ phase ;; keeps track of the phase, O2 [# z' I6 Q, e) `. W
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure3 E' X7 c3 k2 d v
current-light ;; the currently selected light# E2 O1 v: r, V; ?0 V
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;; patch agentsets
+ ?5 ]+ U: ^0 q# g+ z6 ^- n intersections ;; agentset containing the patches that are intersections
8 s% z9 U- G- s roads ;; agentset containing the patches that are roads+ W) M5 B3 _- [6 q
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turtles-own
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speed ;; the speed of the turtle
2 e8 {7 L4 g6 @ X up-car? ;; true if the turtle moves downwards and false if it moves to the right
8 `1 u: `$ C& m+ X: J wait-time ;; the amount of time since the last time a turtle has moved6 V+ u( X1 j0 j! Z$ n8 a
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patches-own
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, ]3 n8 e2 u7 o( Q# w$ M intersection? ;; true if the patch is at the intersection of two roads
0 @+ k* _4 A m6 e2 b green-light-up? ;; true if the green light is above the intersection. otherwise, false.
5 ]& i6 \3 j: I6 z: @; { ;; false for a non-intersection patches.
" R5 N' g: R* f" O( U" N my-row ;; the row of the intersection counting from the upper left corner of the
4 P: h1 e( i( _# ^# G2 A( n ;; world. -1 for non-intersection patches.
) M P, C& H% c4 d7 o& J my-column ;; the column of the intersection counting from the upper left corner of the
* E4 Z. x1 r" {! h ;; world. -1 for non-intersection patches./ B- n& P) ?3 B1 b$ k c/ P" s
my-phase ;; the phase for the intersection. -1 for non-intersection patches.& W/ n8 X4 W5 I u0 y4 y, d7 \6 H) m
auto? ;; whether or not this intersection will switch automatically.% g( j* q+ M. d. R8 r" N3 u6 `3 @) D
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
2 j Y0 u4 Q N' w* r;; Setup Procedures ;;# i* u* R* @& U& \
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.0 t7 R1 M- p. y5 I. M, h
;; Create num-cars of turtles if there are enough road patches for one turtle to J9 M+ D0 I( ^- ~9 ]5 a
;; be created per road patch. Set up the plots.
2 L6 _4 c H( `5 K4 {3 _to setup' ` g; q9 m5 V8 ?
ca
# G3 ]' Y; ?2 Y9 U7 z setup-globals
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7 i- X/ i$ A. B* _" e* E- @ ;; First we ask the patches to draw themselves and set up a few variables. W6 N5 V; ~* p1 W; o/ ^* D2 Z1 A
setup-patches
: d8 f0 M$ g% `9 _( F make-current one-of intersections
' m2 \$ u4 Z7 T+ Q, r$ k4 @ label-current- @ X* ^ F ^7 L1 M& X: J# `1 W
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set-default-shape turtles "car") ?% C3 K9 F6 O+ \
$ \) B* V6 E" i5 A) f if (num-cars > count roads)0 T( \' H& x; T! O3 w
[
' }3 B5 v% |7 c0 m | d( @) ] user-message (word "There are too many cars for the amount of "+ W5 k/ N, `; k. w" U
"road. Either increase the amount of roads "2 a5 Q2 d; c# d% P
"by increasing the GRID-SIZE-X or "
) o3 O+ Q9 O( J "GRID-SIZE-Y sliders, or decrease the ". ?( B5 ^! l2 d0 A7 [7 T& U# C" w
"number of cars by lowering the NUMBER slider.\n"$ T9 X6 N$ U9 K
"The setup has stopped.")
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& O5 A7 E0 r- T ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
. F1 D/ J; a" K6 g5 _ crt num-cars
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/ [* M/ s3 ? H8 i setup-cars
- K. ]" @5 {( I* }- d5 V, g# u7 |# j1 F set-car-color4 @: v2 }' Q) M
record-data
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;; give the turtles an initial speed
: t j. l1 f; i. I ask turtles [ set-car-speed ]
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6 \4 U' c5 n3 z# W reset-ticks
( C5 i+ Z. o- B, Qend
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;; Initialize the global variables to appropriate values; [- j( S" l. E
to setup-globals3 o) N) m( ]$ ]$ D2 H7 ?% P/ n
set current-light nobody ;; just for now, since there are no lights yet
( j3 T4 b# Z( G set phase 0/ w+ G9 a9 f, q' Y) |1 k* M7 J5 o
set num-cars-stopped 0' h1 c1 @* M o0 A
set grid-x-inc world-width / grid-size-x
% b/ O1 v$ f4 q# M set grid-y-inc world-height / grid-size-y; b0 Y" {! p& @& z8 o
, [! _$ [1 O H& Y ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary) D- B5 U# _3 t" l9 V0 c2 r$ L
set acceleration 0.099
) f9 h: |0 n' X% e9 h. O. Oend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,8 S8 N N1 I: a* g8 O
;; and initialize the traffic lights to one setting3 _+ M6 p' @' C% s) L4 p i
to setup-patches
) v2 U7 S- Z3 L ;; initialize the patch-owned variables and color the patches to a base-color4 V2 E) E, _# v9 O
ask patches
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4 m$ i2 T( b: T& O+ x/ W* } set intersection? false
2 c# j) r4 T) Z0 j2 G% ` set auto? false& E3 ]; D& ?3 A* Q; V' f
set green-light-up? true* T8 G' c. J1 l9 j' [
set my-row -1
" l! u" |$ c, C+ [; _ set my-column -1. Z) t6 Q; N! F9 W: O/ C
set my-phase -1
, Q) c) w* j1 p5 F `: T2 @ set pcolor brown + 30 n' n# i* a8 Y. v0 k7 W
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5 V2 R$ z% T8 L! \$ @0 N ;; initialize the global variables that hold patch agentsets& }1 k O1 o. }
set roads patches with, Z3 j# C C" s6 I: \5 a
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" |; d" V9 P/ p6 M- r
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]' H& K. t- ]( O2 M6 N. z& `
set intersections roads with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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1 N8 I0 J/ ?0 e. r' P ask roads [ set pcolor white ]
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end
' n8 a8 e2 o. o5 N其中定义道路的句子,如下所示,是什么意思啊?$ \" |3 N! U0 e2 u
set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 Q% Z x! Q4 H4 _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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