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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。
" h6 N, S) ]& X5 | c: Lnetlogo自带的social science--traffic grid这一例子当中,
! Y- }8 Q% i' l3 L; ]9 {globals
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. C6 Q+ V& U/ Y5 h grid-x-inc ;; the amount of patches in between two roads in the x direction
- s7 [7 n, F o grid-y-inc ;; the amount of patches in between two roads in the y direction
( }. M- K: A2 {! v8 C: p acceleration ;; the constant that controls how much a car speeds up or slows down by if, }% o$ v- y) X. h7 S7 z
;; it is to accelerate or decelerate" S/ \4 `( M% _8 Q
phase ;; keeps track of the phase9 L# D* Z$ a! N
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure% ^0 G& O/ k2 q! z$ @
current-light ;; the currently selected light1 l. H6 T& y( E9 S
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;; patch agentsets# \1 T# C' F! n7 D
intersections ;; agentset containing the patches that are intersections- ~4 n% [# ?7 @4 [/ M. D4 U
roads ;; agentset containing the patches that are roads- q, `& p+ u+ S5 Q' p
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9 ?4 p# ] s1 F5 l- dturtles-own
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speed ;; the speed of the turtle
]% K' b! N( a% t9 W up-car? ;; true if the turtle moves downwards and false if it moves to the right
S1 P: A7 n+ N4 t wait-time ;; the amount of time since the last time a turtle has moved$ R2 ^" E2 d) [, _# B- X& V
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
, t, Y, h/ r+ M5 A e- B9 ~ green-light-up? ;; true if the green light is above the intersection. otherwise, false.
0 ~; V/ e5 L: w% J' r6 o3 J6 V8 C ;; false for a non-intersection patches.
% x9 x8 Q, N% d b- W my-row ;; the row of the intersection counting from the upper left corner of the
# A3 a# Y9 P) T# K+ a6 ^ ;; world. -1 for non-intersection patches.1 u9 s1 Y, O' w7 s. }) S8 L
my-column ;; the column of the intersection counting from the upper left corner of the
; e0 J( y) y$ B5 Z" F( U ;; world. -1 for non-intersection patches.
+ _* R8 a4 s( {! r7 |" q my-phase ;; the phase for the intersection. -1 for non-intersection patches.
8 z% U& b0 j) F9 R auto? ;; whether or not this intersection will switch automatically.8 p. ~6 y# ?9 _# {, K6 I
;; false for non-intersection patches." s! p8 a* L" x# g z
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. K$ _" B7 W# G/ t& F;;;;;;;;;;;;;;;;;;;;;;
* ?. @. Q6 ^% @& }8 z5 i! r;; Setup Procedures ;;
& |& s/ o1 a' c+ P8 Q& V2 L;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values." n+ g" [. _- z( n& R/ H, F
;; Create num-cars of turtles if there are enough road patches for one turtle to6 P p0 l V# R, o$ c g% i5 R
;; be created per road patch. Set up the plots.
# }% R2 C" I5 o/ sto setup
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. Z' U% o* l* n$ d% p, p ;; First we ask the patches to draw themselves and set up a few variables
6 a- V! Z* `6 r5 p& M% L7 K setup-patches2 Z9 }9 u2 F5 |0 M& V% {& O6 \
make-current one-of intersections
" A4 G' I3 k, G, l, W# L% m% j* G# J label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)# l# i& x8 @& U6 A# P8 P
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user-message (word "There are too many cars for the amount of "
# e+ ~$ r$ H$ i/ T5 [- g "road. Either increase the amount of roads "4 a+ k6 o( ]9 M
"by increasing the GRID-SIZE-X or "# Z; r) r' t/ Y: `- d
"GRID-SIZE-Y sliders, or decrease the "* ]4 A3 \2 u$ ^
"number of cars by lowering the NUMBER slider.\n"7 L& S' Z, d9 O
"The setup has stopped.")
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# o" T1 q S2 e, ?9 G8 ]" m; s ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
' @- n9 H: C+ `+ ?* ] d crt num-cars
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/ M1 k+ u( a# v L& V8 I4 ~ setup-cars" s1 w, z [" ^& r
set-car-color
5 X) B& K5 _/ F6 x; h record-data
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" u d; s+ Q7 ~7 U( \ ;; give the turtles an initial speed* R& C( }; |0 v, Z- m
ask turtles [ set-car-speed ]' c& h. x' W( h% E4 l6 C+ n% v' N# ^
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reset-ticks
5 P- ?, A# o* v3 z8 Iend
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;; Initialize the global variables to appropriate values
; U9 l. o7 C+ l9 c: f% n0 F. ]to setup-globals: E' R/ i3 @+ a- N5 j* b- l/ N
set current-light nobody ;; just for now, since there are no lights yet L& ]/ X7 |7 G& L7 L) E
set phase 0
3 D3 H/ ?, e9 L1 S8 r, R+ ] set num-cars-stopped 0 |& C: D- C6 ~& y [3 t
set grid-x-inc world-width / grid-size-x
2 i4 f; v- A, b i F1 E 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 boundary
$ ]5 L- j& r2 }% ]* p0 z& X. C0 g set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
( y% b$ R5 x9 R N;; and initialize the traffic lights to one setting
9 I0 Q7 ^' O3 [% C9 d, z( M rto setup-patches
+ o# B' N) Y+ O/ ~, X) M ;; initialize the patch-owned variables and color the patches to a base-color
; O4 \' J' \& i7 C F( l8 k4 t) ~ ask patches
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set intersection? false# G& Q9 T7 W$ s% w
set auto? false
[" \ B* |8 \6 a set green-light-up? true7 @ r0 b6 w9 m, q/ h: k
set my-row -1
- G6 E8 L- t3 N/ p set my-column -1
2 W# N% s; U& D+ t& n) c set my-phase -1- n: t* P4 D3 S8 N# k- E. F- |
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets l/ Y! p7 {: }; V' c2 q
set roads patches with/ p, b0 r6 e% z3 {0 D, d( l
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
\# z4 r: }4 \) q4 H. j6 n (floor((pycor + max-pycor) mod grid-y-inc) = 0)]( m+ Z% o; l; p: O
set intersections roads with. |" v. q; X& B
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and* F" b" G7 B+ l0 Q! k9 `: t
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]! E K) B2 H! {; b6 D4 X1 R9 B
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ask roads [ set pcolor white ]
) `6 h/ x' T& P8 z8 Y8 j) b setup-intersections9 y1 d- r- I& J3 ~. V3 v
end) P9 \! {* q; e& _) M
其中定义道路的句子,如下所示,是什么意思啊?
1 b* y( k% C( {# k( W, l% X set roads patches with; S/ U6 w2 K; c# N! B$ x. m
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or9 @: c8 e; G+ |4 s
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
( z5 q s& a$ a% o, }& p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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