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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。- T2 V+ V" G9 a
netlogo自带的social science--traffic grid这一例子当中, O, `& n/ R. Z s" Z
globals) r1 I. h8 ~4 x& g) q( r
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grid-x-inc ;; the amount of patches in between two roads in the x direction
3 c: H' R/ ~9 k, ]& q grid-y-inc ;; the amount of patches in between two roads in the y direction
; x1 x- K8 U2 m) O6 b) i5 f acceleration ;; the constant that controls how much a car speeds up or slows down by if
* B1 U7 a; f+ c7 M8 p X ;; it is to accelerate or decelerate6 P8 b" G: d3 m* T
phase ;; keeps track of the phase
& K$ v6 [& c' O/ h2 M num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure& ^. C$ ]9 o3 Z0 j
current-light ;; the currently selected light
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$ G0 I2 v6 N) S+ g4 k9 h( C ;; patch agentsets- ] k! q/ b6 R& u5 f: n
intersections ;; agentset containing the patches that are intersections$ R$ X& u Z6 T
roads ;; agentset containing the patches that are roads
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3 d/ O6 m( `7 k: s$ Z3 qturtles-own
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" I# Q3 B% I" X' k speed ;; the speed of the turtle' n- P/ i7 n3 _) B2 m
up-car? ;; true if the turtle moves downwards and false if it moves to the right h) s3 v0 ^- ]" [2 v. G
wait-time ;; the amount of time since the last time a turtle has moved
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" h2 c% e: u2 \/ ?6 Kpatches-own
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, x& [" {& l# ~& O3 }5 l intersection? ;; true if the patch is at the intersection of two roads
, {- _; j* ~. m5 T" y' X green-light-up? ;; true if the green light is above the intersection. otherwise, false./ M( p p8 H. G$ e5 l0 _+ r; S
;; false for a non-intersection patches./ ~; d Y) m# ]$ E
my-row ;; the row of the intersection counting from the upper left corner of the
, q/ c3 ]! [6 n ;; world. -1 for non-intersection patches.
) g- _8 ^6 a6 r# L6 C- [ my-column ;; the column of the intersection counting from the upper left corner of the R9 s: h5 N; {3 m9 `
;; world. -1 for non-intersection patches.) \& `9 s( m1 G2 c9 v' y
my-phase ;; the phase for the intersection. -1 for non-intersection patches.) G2 ]0 u) n1 S& U8 F' _2 z$ ]; @! }
auto? ;; whether or not this intersection will switch automatically.
, Z+ t$ [& n' ]1 q/ X1 E7 K+ t ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
6 T4 a4 a5 C! S) r' Q4 };; Setup Procedures ;;
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6 [6 Y9 e; K2 Q) ];; Initialize the display by giving the global and patch variables initial values.2 _" I1 J. T1 j# [
;; Create num-cars of turtles if there are enough road patches for one turtle to
0 f# H! G4 a) }1 x; A;; be created per road patch. Set up the plots." B/ c& _6 S, A
to setup, {' H6 R u& N. |
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
2 v- T( D, I; r1 l) y setup-patches ]& H; }* P& J# P ?
make-current one-of intersections9 E: j# }5 W5 a& j' A; m; E: p; ?
label-current# k2 x1 D. \' ~5 i0 D O
' f% I. X K6 B/ ?% b set-default-shape turtles "car"
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if (num-cars > count roads)
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9 R p! h; h I2 U. D! \6 w user-message (word "There are too many cars for the amount of "
% B: u& e/ S0 Q$ G! v "road. Either increase the amount of roads "
6 F- O" s- L6 `# T8 z7 u/ p9 U* a: L "by increasing the GRID-SIZE-X or "
3 h0 ]2 [3 x$ {# s "GRID-SIZE-Y sliders, or decrease the "
% p) Z; S% |: I s$ E7 t, }% V "number of cars by lowering the NUMBER slider.\n"
! Y# w2 V7 y. @5 W) K P1 b0 H "The setup has stopped."). x$ M1 b/ O G- w
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
6 {" V9 q; N- _* j5 E crt num-cars! {% @+ e6 ?: j6 {5 i j; b. d
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setup-cars' y0 J5 y" e; n; H
set-car-color: c) U' e5 i. @! M6 M
record-data
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;; give the turtles an initial speed
5 V' r$ N+ p0 r- V1 Y1 B$ w ask turtles [ set-car-speed ]
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reset-ticks
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' r/ E9 l. s1 U# L) w;; Initialize the global variables to appropriate values n. u! O% R2 h n6 ]* _$ `& B) i3 a
to setup-globals( h# `/ w$ V2 d* [$ U0 f9 l: z
set current-light nobody ;; just for now, since there are no lights yet) ]4 A, s3 ~, A3 c) a! K# S" R( {
set phase 0
9 T* w1 ^+ }+ N; G3 K/ e* ? set num-cars-stopped 0+ ^! O, p( }! m$ h& N- O2 K
set grid-x-inc world-width / grid-size-x7 v8 s2 w: C4 D% A* B2 {: E; b
set grid-y-inc world-height / grid-size-y" e7 g- s" Z- n- K# L
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
/ D6 W" v$ n7 T# b( r( L set acceleration 0.099 {- t0 r/ J" G! X$ W9 _
end
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+ i# j! H" ~9 p' S, r2 P. u;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
} D: ?& N/ K1 o% P9 ^;; and initialize the traffic lights to one setting
3 }& n( |7 i8 Y$ G+ t! sto setup-patches+ j. s, Y5 ~/ P" m6 g5 b7 r
;; initialize the patch-owned variables and color the patches to a base-color
. f' h6 v* Y/ y2 N ask patches
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set intersection? false
) j, p- p: M, @- a! s, q set auto? false5 M6 i# [0 I1 H5 H
set green-light-up? true
( s e0 F5 K1 v! }* w: c; A6 B- p0 y set my-row -1( e8 c; Q6 j- ?0 o
set my-column -1
* |8 a, A: l( X+ u* S. g$ {, h set my-phase -1. I* T+ L; R4 M1 u, z6 \: J4 R
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
/ [9 e0 }6 R# r4 a" f set roads patches with: a: p# h4 S/ C6 R$ Z n0 ?
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or. E& O$ {5 C2 j: T7 ` Z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, G' w6 Z0 L$ O, J+ D# d" u6 q' H set intersections roads with
% Z" j# { u6 {/ L J) c5 Z( m [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and1 A# ^" m# u* I/ \+ Q
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]' g K# F- S6 i8 a6 h9 s) A
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ask roads [ set pcolor white ]( {$ I( j8 Y% _4 Y# j/ k8 u1 d9 g
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?
. w0 f, f ^6 g0 h( E set roads patches with1 m# Z- |$ g5 z9 g, J+ ]' w$ V
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, Z( X. h$ a o- K
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
4 \) A7 I& P0 C+ \6 Y) x/ O8 N( N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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