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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。5 [% q% H. o% ~% R X0 R: }
netlogo自带的social science--traffic grid这一例子当中,; Z# m8 M4 s2 c4 C& K8 C/ u5 P& U
globals
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4 V3 o$ B, s- j# t* c grid-x-inc ;; the amount of patches in between two roads in the x direction
# P# `4 h& U7 Z' R; s3 w. |9 w! a grid-y-inc ;; the amount of patches in between two roads in the y direction
; \. |6 s+ z, ?- } acceleration ;; the constant that controls how much a car speeds up or slows down by if
9 Q3 K* j) n+ p. Z( v$ I ;; it is to accelerate or decelerate
- i9 m) u3 `& O: K* H phase ;; keeps track of the phase
- F0 M' ]* ?3 D5 M% ?9 w2 G num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure; b( B8 \3 L) T$ z5 Y6 n9 s& o( k
current-light ;; the currently selected light* E! y. O! ^9 _7 }
$ R5 Z4 @5 D! A. ~+ ^ ;; patch agentsets% P( d: ?4 Z8 F- e: l* l
intersections ;; agentset containing the patches that are intersections* e2 T+ k# t& | s7 D
roads ;; agentset containing the patches that are roads
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: Z% R- {% u9 Q, v$ wturtles-own
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speed ;; the speed of the turtle
" B" w3 L9 [3 l/ ~+ q p7 }' D$ c up-car? ;; true if the turtle moves downwards and false if it moves to the right
% Y3 L8 C* w& v$ @; P wait-time ;; the amount of time since the last time a turtle has moved/ Q! h+ R3 P% b5 p2 K p4 n; @2 E$ ?
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patches-own
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8 Q% I7 v% `3 W! { intersection? ;; true if the patch is at the intersection of two roads
9 ^6 x L7 O' u2 H green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! T! F m" v/ I% @9 P ;; false for a non-intersection patches.9 i' w% D: `5 y i
my-row ;; the row of the intersection counting from the upper left corner of the0 l t& O! U6 j9 f: f
;; world. -1 for non-intersection patches.
% L; ]; ]: Q/ D- \: c( v+ m5 w my-column ;; the column of the intersection counting from the upper left corner of the
2 m" L8 p$ q, M ;; world. -1 for non-intersection patches.
* w2 {7 g+ [9 G# X1 Q2 q9 I2 v, D my-phase ;; the phase for the intersection. -1 for non-intersection patches.
6 F' i$ D4 Y& ]/ D auto? ;; whether or not this intersection will switch automatically.
& g$ B$ m' C2 ^ ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
! L+ ^4 ?" m* r7 k; u;; Setup Procedures ;;+ J- C0 S1 i7 R, g
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;; Initialize the display by giving the global and patch variables initial values.
1 P' z. o( q; M# ?% ~* ?;; Create num-cars of turtles if there are enough road patches for one turtle to
0 H( `% p' {1 K: ]( {) z" C;; be created per road patch. Set up the plots.
6 I; B2 D1 {; W I0 t$ {7 R* Y( \to setup
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
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make-current one-of intersections
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4 h1 H% M( b0 j+ @7 R: m set-default-shape turtles "car"/ U, U! i5 O5 M6 d4 j$ l
! Y) R) H; m/ f( V; G; K, z) v if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "# T0 ~4 ~( b4 B# N! ~
"road. Either increase the amount of roads "
% f) a5 o' G! V "by increasing the GRID-SIZE-X or "% b2 i! ~9 f1 I3 h
"GRID-SIZE-Y sliders, or decrease the "9 x$ f, U1 Z9 T! }/ o1 v
"number of cars by lowering the NUMBER slider.\n"! ?" O1 e& f) {8 i+ I9 [+ B% t
"The setup has stopped.")
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' E* e7 \; B N9 x: C ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color' n1 V3 h& o" i: E Y
crt num-cars
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) `* g2 e [4 j; p! O: V4 } setup-cars
0 ? P, \0 }/ B% g set-car-color" {) g, t( ~# B% ?/ n6 P* a) |2 ?5 q
record-data
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;; give the turtles an initial speed4 ~8 @" y# S4 D4 s( v$ ]
ask turtles [ set-car-speed ]( G% J- G, {( [' Z, l6 p
: G1 ?# T& v7 N g9 {& ~ reset-ticks' x' U! }" r1 G4 q: G
end) z7 i" w7 {/ R" [
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet1 v$ p3 F4 U0 T
set phase 03 g# T+ G _- D$ y7 z' b
set num-cars-stopped 0/ c( y/ c+ k( J; @% p& n
set grid-x-inc world-width / grid-size-x
7 g/ f2 H* B4 V' S2 x set grid-y-inc world-height / grid-size-y m1 i$ W" T( Y* V! }) c/ A8 I: F6 a
% S8 l# w: @: v- _, { ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary5 b$ K7 ^6 T) w: e
set acceleration 0.099! v, P! O$ Z1 L- m8 h3 X( j
end; R2 j9 P/ b0 n; F2 ?. O+ M
+ C0 B ^ l! l;; Make the patches have appropriate colors, set up the roads and intersections agentsets,* }3 E, i8 s/ X" p' F. a
;; and initialize the traffic lights to one setting
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;; initialize the patch-owned variables and color the patches to a base-color6 R$ D6 `7 P1 S- p$ b" U) C
ask patches
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set intersection? false) L7 Z& P% u* u, R/ {, t7 b8 h( ^
set auto? false" \' Y7 P$ ~* ^) u: b1 r
set green-light-up? true
* M9 p# V3 i* Z. I' u, s7 @ set my-row -1% C: p% _7 U3 b* k, p O- t
set my-column -1
8 M1 R) l' T3 D2 o# m4 S set my-phase -1( G" e4 t' t/ L& h% z& Y z; a8 e
set pcolor brown + 38 b) j% V0 @4 w; m; Q5 J
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;; initialize the global variables that hold patch agentsets* \( j1 J: D6 q# a! i
set roads patches with
: \, }- P) C5 O) o8 ? [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or/ y9 y) T/ J: z( }8 D7 ^8 g
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 n$ \5 e3 @7 ^+ Z
set intersections roads with
! S8 J( z) ]' T2 y) d& K5 i [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and5 U$ x, U' W7 p5 @2 ?/ O+ b# Z: R
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 J; e5 ^1 H+ `+ n$ s4 G* z( Y( W
! N# I- ~7 V5 I/ D ask roads [ set pcolor white ]) [! _' Q: [& H
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?
i Y+ l+ [' C set roads patches with1 T3 }, Q& _7 C! a6 h
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or4 F0 |, l3 k8 V2 N0 n# {$ E' P5 Q
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]& a9 n) n* ]8 f) i' n4 Q1 X. v
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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