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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。
! [- q' c# }/ e; c( D% hnetlogo自带的social science--traffic grid这一例子当中,0 m: }0 o n' b4 |: x4 G
globals
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$ I/ e* T7 J, H% r grid-x-inc ;; the amount of patches in between two roads in the x direction
/ a+ u; j( ~8 u9 Q( ~; q grid-y-inc ;; the amount of patches in between two roads in the y direction9 e2 S; v2 V9 T% I; d
acceleration ;; the constant that controls how much a car speeds up or slows down by if6 t, G" F7 t5 n
;; it is to accelerate or decelerate& h* x/ v4 v7 r5 T: l
phase ;; keeps track of the phase$ T' j& p) q r; a
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
& x5 Y5 @1 U" d# _3 [( X1 T current-light ;; the currently selected light d% q9 I4 L; H+ V$ |
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;; patch agentsets
! e- q. T( a) w( Y! a" c, d intersections ;; agentset containing the patches that are intersections1 h& k5 s; V4 e/ d" k* x. |! L) |
roads ;; agentset containing the patches that are roads, R9 F5 X8 P3 G6 X) P2 R
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8 y6 B; e3 f5 B: I; \8 zturtles-own/ ?4 T4 Q9 C; v+ B4 `) {
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* i" z, A0 v5 V, m" p. Q; V; p speed ;; the speed of the turtle
! k" s* _' L. P$ C% X up-car? ;; true if the turtle moves downwards and false if it moves to the right8 y/ } @' N4 `, p0 W' I B& u
wait-time ;; the amount of time since the last time a turtle has moved
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- {4 d ]' Y* ]. S# b! U3 Cpatches-own% m9 L" E, G& a/ `0 y1 p
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7 V" v* u' Z" j intersection? ;; true if the patch is at the intersection of two roads9 x' }+ j. `. k; \+ P {0 W
green-light-up? ;; true if the green light is above the intersection. otherwise, false., F- Q: D( H& ]# Q8 I7 F
;; false for a non-intersection patches.6 K; q' A4 u Y
my-row ;; the row of the intersection counting from the upper left corner of the2 n! L" a- M, Z2 w9 R1 s) [% r3 g$ B
;; world. -1 for non-intersection patches./ s3 ~1 e$ t! _* w$ D
my-column ;; the column of the intersection counting from the upper left corner of the5 Z9 f+ l2 }* Q3 a. H+ i4 Y9 Y2 ~
;; world. -1 for non-intersection patches.
9 R/ l0 o5 G0 |9 U9 P& h my-phase ;; the phase for the intersection. -1 for non-intersection patches.# c3 K9 H. O) z; H
auto? ;; whether or not this intersection will switch automatically.5 M" M5 Q, e( O0 m/ I
;; false for non-intersection patches.0 n- X; ?0 v, f9 Z# r1 S
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) M$ \" S6 T* f8 I2 T;;;;;;;;;;;;;;;;;;;;;;
; l0 u8 f8 F5 l0 G6 N;; Setup Procedures ;;# G) X8 X6 ?$ d+ V- O5 t
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;; Initialize the display by giving the global and patch variables initial values.6 z* x9 L y0 Z) R
;; Create num-cars of turtles if there are enough road patches for one turtle to
) i0 {. X( u* z2 _; i: U;; be created per road patch. Set up the plots.. A k0 I( a- _* X1 r5 M: s
to setup
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) x! }) t+ t, A7 s) g& d setup-globals
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; {: K# i b4 B; H& J ;; First we ask the patches to draw themselves and set up a few variables0 t3 s5 u, B+ R* {6 A9 r0 ?3 F
setup-patches
' r+ ]4 o! H% a9 f, Y4 L# Q make-current one-of intersections/ J! |5 |" t0 ~: O6 }
label-current5 @1 [1 w1 T4 L8 C
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set-default-shape turtles "car"
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if (num-cars > count roads)
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2 x$ X7 h' c4 x& K- F- H user-message (word "There are too many cars for the amount of "
& T3 n) C7 @+ y "road. Either increase the amount of roads "
: d6 F' T1 ]8 t6 z6 S0 a% v7 p- l "by increasing the GRID-SIZE-X or ") {2 l( l( A9 C1 l( }+ J
"GRID-SIZE-Y sliders, or decrease the ") ~1 I) u+ f4 P$ b0 ~
"number of cars by lowering the NUMBER slider.\n"
- r2 r. p; {4 d& B$ r: o+ ^6 V "The setup has stopped.")
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color2 }8 X7 q+ D& O; C
crt num-cars$ q8 Y; L( P+ N( N# l* V
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/ E- v) H! E# X7 d; b# J7 ^ setup-cars" v$ y# Z* g+ Z. m$ T4 b7 G
set-car-color
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" d3 t1 Y# s4 E, d ;; give the turtles an initial speed
?, A1 J4 \5 F8 \4 T) Y. g! K ask turtles [ set-car-speed ]
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* |# P0 |& ^2 w8 o' y, C0 @ y reset-ticks
5 d2 T; s+ k$ F- L \end& e$ P9 @; d2 J% c7 M) H% k0 J
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;; Initialize the global variables to appropriate values: T& [! o; ]/ n
to setup-globals
& b" b' A5 t; e. ~ set current-light nobody ;; just for now, since there are no lights yet
4 G' Q3 }1 d) V( d' ~. K: S set phase 0, N! T2 V: W9 c/ Q7 C! N% s
set num-cars-stopped 09 i( i6 e4 o! j v* b+ D! }) g3 U
set grid-x-inc world-width / grid-size-x
1 z( ^" f; k+ q/ v3 ^% h! S set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary4 O& ?& _. ]% x7 Q7 {3 x B0 H3 v
set acceleration 0.099
2 t9 u( A B! P, ]0 mend: ^+ ^- n9 I5 d- `
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
0 S6 E+ s; ~; b1 V;; and initialize the traffic lights to one setting
9 S4 u( h/ T. p, Ato setup-patches; A7 o% ~3 F" q% j" ?$ ]
;; initialize the patch-owned variables and color the patches to a base-color& j. O5 f# j. P4 P# [' Q
ask patches A' \% g* p/ s$ c, g
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8 f9 @) \) p. b+ Q' P) D set intersection? false; r, \# _2 Z, I) J% i. g! W, E
set auto? false
$ | L7 B- k1 l/ s W- N& Y set green-light-up? true
+ o# ?: M. }! g5 A set my-row -1& A& m/ S! T& v
set my-column -16 w7 \' Q1 g5 M$ P% \
set my-phase -1* s& g6 h1 o- h
set pcolor brown + 3& h; _+ }/ h. M# t! N" @
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;; initialize the global variables that hold patch agentsets
( T5 l+ k$ ]) f- U1 s/ P set roads patches with- ^+ {. `. u" ^' h( j
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or& d& }2 b8 z5 V* c. M
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 F' _5 F3 j4 ~; h4 X
set intersections roads with0 m( Y6 R, I Y: z% ]
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
, y* K* d6 |- a9 j* A (floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 Y+ a8 \: W4 f2 i T- {8 ~
2 ]6 e! ^; C8 r, I# Y( v% U ask roads [ set pcolor white ]
8 O- W6 B, [# A& }& u @ setup-intersections: u3 k0 q! ?% p3 r+ n! t
end
; ^9 w% Z6 X3 w7 q3 o# x3 C. G其中定义道路的句子,如下所示,是什么意思啊?
! y& z! N, c" B set roads patches with' [5 k9 X! f+ q. G J4 R, w( @% x
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! A( p( l8 p; x+ X( h/ c (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" E9 C M9 [# e& }( x* }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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