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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。
) S, e, u# {3 Onetlogo自带的social science--traffic grid这一例子当中,1 i- N k+ {* W5 Q S1 M o
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction7 O% ~( W7 Y- c m0 O9 _- P- l& x
grid-y-inc ;; the amount of patches in between two roads in the y direction
9 ~) r z, x! t$ O2 { acceleration ;; the constant that controls how much a car speeds up or slows down by if
% f- C" w5 a" q- m0 \0 o ;; it is to accelerate or decelerate5 u! {) n* x( ~
phase ;; keeps track of the phase- j1 a: H# j* z; D) T# d
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
9 c. m" m( G/ G+ g8 F9 h current-light ;; the currently selected light
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1 B! D# c; O4 G/ Y1 l ;; patch agentsets: g& S& u! k$ \; l3 B' y
intersections ;; agentset containing the patches that are intersections
$ d2 A1 \" _" }5 {6 d3 H1 N roads ;; agentset containing the patches that are roads
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4 U! e3 N& p5 [turtles-own! m+ S" B! Z( K' t P
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speed ;; the speed of the turtle
8 X* u1 K; J2 c1 W" O! {- _ up-car? ;; true if the turtle moves downwards and false if it moves to the right
, L& s' w. _- Q, n3 T* D, W wait-time ;; the amount of time since the last time a turtle has moved& `$ \" r O. S r9 d7 b+ p+ q( H
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! v7 x0 ~% C6 @; U, R9 U7 {patches-own
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intersection? ;; true if the patch is at the intersection of two roads
. T: X; h1 H6 `* N green-light-up? ;; true if the green light is above the intersection. otherwise, false.
' d3 r' y; l9 i8 v! f ;; false for a non-intersection patches.
1 t, z D: t6 _% K' j( W: W& J- b. t& n my-row ;; the row of the intersection counting from the upper left corner of the
! j+ P7 U1 i; K ;; world. -1 for non-intersection patches.7 h4 s' g, y4 S3 F
my-column ;; the column of the intersection counting from the upper left corner of the2 s- }8 ?2 e; S2 V
;; world. -1 for non-intersection patches.
; M K: p( n0 V! B0 Z0 h/ i my-phase ;; the phase for the intersection. -1 for non-intersection patches." N0 a0 m+ N% t- [2 I
auto? ;; whether or not this intersection will switch automatically.9 k c B; k* d8 v2 S
;; false for non-intersection patches.
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2 Q0 r; \' u+ J6 g$ p;;;;;;;;;;;;;;;;;;;;;;
* Z9 R5 B9 i4 w2 j9 E$ i! B' s, e( B;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.8 R& F+ X# V3 ~& a; s- b* o2 e
;; Create num-cars of turtles if there are enough road patches for one turtle to& V& }; _* b4 [; f6 F- N* r4 t+ h
;; be created per road patch. Set up the plots.) t# }6 W+ M% g/ N. v4 d% v! F8 i
to setup' n) a, E% L6 j' c. `) w
ca
$ |. d; v8 C" ]: ^# s7 t setup-globals0 \7 C; R5 P( E" G# d" a) I; I
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;; First we ask the patches to draw themselves and set up a few variables
: T8 `+ C& H: @( P1 @# W$ V* u setup-patches
- I# x! f5 [% L, v make-current one-of intersections" X' A1 @, b; Y! D( y$ x
label-current r( f: D( Y, {; g/ b
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set-default-shape turtles "car"
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if (num-cars > count roads)
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; X! a4 H) o* B user-message (word "There are too many cars for the amount of "! R! `8 Q! I. s% i
"road. Either increase the amount of roads "
: d/ Z7 P2 M% H0 C; f "by increasing the GRID-SIZE-X or "
, W, ]7 B C) M) c& t9 m0 o "GRID-SIZE-Y sliders, or decrease the "
% `0 a8 E* Y [( k "number of cars by lowering the NUMBER slider.\n"
o) P5 i$ m5 N/ r: o4 f) r1 d "The setup has stopped."), `( Z7 }% Y/ \; |* o8 I2 e3 ^
stop- m/ ^, @% U& g; t6 q+ R
]
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color8 _' @! {, u( A9 k( }- F
crt num-cars8 `; Z# W9 T7 B7 D1 U) f5 h
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setup-cars6 H6 z" |: {- k! d) J
set-car-color% \6 n5 \0 u T6 J
record-data
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& b/ Q. @5 @: s' q# R# c) J ;; give the turtles an initial speed
6 R1 O2 G% R2 K1 Q2 l ask turtles [ set-car-speed ]
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reset-ticks
( M" S; ]; m% @3 eend
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/ Q. H' W6 u" L4 S;; Initialize the global variables to appropriate values; V7 m7 E, l9 l: q6 k) P$ e
to setup-globals: l4 l4 ?4 V8 Q9 t
set current-light nobody ;; just for now, since there are no lights yet" `' Q5 f9 y+ j) q# X, X$ B
set phase 0
( ^; h! ~9 V6 s. Q. `& [3 x7 {% j set num-cars-stopped 0( V1 x( q, \6 f
set grid-x-inc world-width / grid-size-x
( ^5 j2 M8 Y9 R* ` set grid-y-inc world-height / grid-size-y8 I+ t2 }4 b. y8 b# ~4 ~' x: S
2 c0 Q: k: F3 G& `# Y: r" Y ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
* I& t- P% I; t- ^& c7 j3 O6 G set acceleration 0.0994 n& Z1 ?9 Z+ r5 k
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
( @& m4 q6 [* e( ?& |;; and initialize the traffic lights to one setting. o6 R" I7 q) l& X
to setup-patches1 Z4 d1 K$ D9 J/ `* Z
;; initialize the patch-owned variables and color the patches to a base-color
3 a F% d( X S4 f! @* { ask patches$ H) K* d" S( P; r- u; h
[
+ u! v+ `7 z. [8 e' w set intersection? false
$ y2 {, g+ x0 k0 \/ ]+ G set auto? false
6 i. h4 d4 c! s3 G+ w" ^" m; O& ~ set green-light-up? true
( V1 w7 ] G! k h" \ set my-row -1
7 Q, s! y% m" }7 k6 a) b set my-column -17 T) I9 n2 i r0 S
set my-phase -1; ?+ [* ?; Y% B3 w
set pcolor brown + 3, o3 c6 }) M9 X, B
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;; initialize the global variables that hold patch agentsets# L8 C' G, J/ N) s
set roads patches with; n' D9 p2 N! L% z1 g
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or9 Q& D& `' T5 H9 {1 p% l5 c
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 H4 t" \1 r; l: k4 J' ?
set intersections roads with
2 Z s+ n1 ]# q1 X. e9 {3 D: u [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
) _* t9 z3 L0 B' a' h: m (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 T4 J T) X [# {
( g1 _# N; r( I! b ask roads [ set pcolor white ]1 g, P% O) |" Q4 J$ ~
setup-intersections
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9 X' y6 W. V( L, [* R! v其中定义道路的句子,如下所示,是什么意思啊?* K& F# n: _4 W
set roads patches with
9 \% J/ R; r; \* U9 c [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
+ }( R8 z9 d: U! W. r" p (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 c$ o) d* p5 }: ~! O( q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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