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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。
! k% m' w* K. g6 t% A9 u( s6 Knetlogo自带的social science--traffic grid这一例子当中,
1 E ~. n4 t- n& M$ Dglobals$ o/ U$ v1 h' l4 S; I
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grid-x-inc ;; the amount of patches in between two roads in the x direction
8 r5 D& O$ c) z2 D grid-y-inc ;; the amount of patches in between two roads in the y direction
/ H% }2 M0 G" J7 e acceleration ;; the constant that controls how much a car speeds up or slows down by if; h+ x2 z; ]3 x
;; it is to accelerate or decelerate8 ~; W+ C' w2 `4 {" e
phase ;; keeps track of the phase
0 E& B0 d' n7 i$ a* ] num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure% r l) k' L8 b& |& j- s$ i, p
current-light ;; the currently selected light4 n7 V D( d! R! \, e7 J E
6 s ]* S( v3 n( s ;; patch agentsets! L2 G5 N# e& D7 x+ X% f
intersections ;; agentset containing the patches that are intersections
1 R: L! M& I. w roads ;; agentset containing the patches that are roads
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/ y W g& Y' f* f [ y3 ?: q# Nturtles-own
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speed ;; the speed of the turtle0 |% x8 P8 a8 c
up-car? ;; true if the turtle moves downwards and false if it moves to the right; B+ `" k; o9 e( k
wait-time ;; the amount of time since the last time a turtle has moved$ U1 O0 N: ^( |( c$ V! E4 h
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads8 E8 E1 D9 w2 s, M \7 U( ]
green-light-up? ;; true if the green light is above the intersection. otherwise, false.+ O5 r: O3 v9 ?, f3 [/ x h
;; false for a non-intersection patches.
* ~" I" E$ \; h" ~& W6 a my-row ;; the row of the intersection counting from the upper left corner of the
; K! S& d* X) T% x @3 I2 r ;; world. -1 for non-intersection patches.
7 g& ^, a. X. I my-column ;; the column of the intersection counting from the upper left corner of the; G1 @4 ~6 S' i* B9 t4 _
;; world. -1 for non-intersection patches.+ {: H, {3 S% E9 g0 q7 }' C
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
0 U5 \" e% p& @ auto? ;; whether or not this intersection will switch automatically.
5 }) X# ]0 A9 ~/ i9 d ;; false for non-intersection patches.& F( w5 a9 j) W! [- I
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8 O, [; Y8 l; J, y j% P8 g;;;;;;;;;;;;;;;;;;;;;;
7 ^7 b2 W( ~% N' z; v0 q;; Setup Procedures ;;: u2 a( Y% T' ^9 [
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.) q1 E( u3 T* r: e1 G
;; Create num-cars of turtles if there are enough road patches for one turtle to
6 T8 V% ~$ a9 Y8 h3 h( T: S5 N;; be created per road patch. Set up the plots.
2 t1 j. S; @3 m9 k# \- Q; B% @/ o4 Hto setup( [ [3 p& O6 g, p3 S- k! L
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setup-globals1 Y" P* D; c: ?8 h4 c
) b! H* Z" p7 E ;; First we ask the patches to draw themselves and set up a few variables* v6 i: E5 H' C8 A0 N2 H
setup-patches9 Z% j. Y) j6 P0 Z5 R! }
make-current one-of intersections
( M: I* @# c7 N3 L! A0 w* `# C label-current% A- Y) m: j; G, v {: S4 H
1 W6 i! |; ~1 R set-default-shape turtles "car", l/ a& Z" j+ z A& s- G- P; K
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if (num-cars > count roads)* ^! K4 n& E3 U) `: b, S/ ^
[
2 T* {. d+ l8 H: @- w user-message (word "There are too many cars for the amount of "6 K+ I* ?$ j7 h
"road. Either increase the amount of roads "% O1 h( V( J0 i' W: `/ W
"by increasing the GRID-SIZE-X or "% P" p; u$ m( d/ \: W
"GRID-SIZE-Y sliders, or decrease the "
5 n& m. r$ i ~5 w "number of cars by lowering the NUMBER slider.\n"
$ E6 L2 e5 z( P4 u3 y2 D0 h "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-color
+ P0 ~+ C7 m K1 t$ `, T% c crt num-cars
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setup-cars
2 V0 u! h Y5 } set-car-color- X# c v9 J2 R/ i0 F5 S, ~. \
record-data" n# s0 U* q6 F$ e
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4 ]/ U% J0 ^0 n) l! r6 L, M1 v ;; give the turtles an initial speed
% f# N' p5 f: D! }2 e7 ]& v7 ]# U$ h) i ask turtles [ set-car-speed ]
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8 ]# P U a E8 j8 H" l reset-ticks, S4 ?/ q2 W2 m4 T: ?
end* L1 q3 o5 i7 i) F4 q) U# l% ^$ ]8 K
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;; Initialize the global variables to appropriate values
2 N! ? @! F: u' zto setup-globals6 k/ B% }2 \+ t; m1 M, l7 i3 k! U
set current-light nobody ;; just for now, since there are no lights yet& H' f: O% ?# |/ ]; k0 H
set phase 0
* i2 l7 L0 u' G O set num-cars-stopped 0) `* `! J. ]# Z: K( X
set grid-x-inc world-width / grid-size-x
- m6 u* u# r6 L0 Y( Z8 U set grid-y-inc world-height / grid-size-y1 Y+ P0 C* c+ D$ K! G5 e* X7 | A
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
8 p3 k7 v! W' G+ S5 h9 d set acceleration 0.099
# m9 M: H, v }) d/ J6 M3 |end- a* ^% ^- J0 j1 v9 T3 S
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
& S+ ^9 f `2 a2 [/ Q;; and initialize the traffic lights to one setting9 n/ U* w5 G- b4 d
to setup-patches* V5 ~' n7 b2 ?3 l
;; initialize the patch-owned variables and color the patches to a base-color
n% _: o1 H6 r& \ ask patches
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. O& U, ]- a, l/ S8 z set intersection? false% z% P# H0 i& m" L4 y* v4 x
set auto? false. z, H3 \& w; [5 V9 t
set green-light-up? true
- _5 o( P" ^7 }: T M3 w, B+ H8 a set my-row -11 K& n& D+ F" B1 O
set my-column -1
! ~; [. A; x' n" X set my-phase -1* I/ T# E7 |1 g5 @2 A; [
set pcolor brown + 3! B3 f; B. u/ N; h. v/ i9 p" v; v
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;; initialize the global variables that hold patch agentsets2 v9 b1 C2 I6 ~* n9 j0 z
set roads patches with2 x; C) B3 }. H4 }
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 r; v# [* V- g1 B) Q: q# M
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: H9 X, B8 _ K: t) q! f- t1 b/ G set intersections roads with$ O+ Q/ w: F, E2 ^ q# F
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and; q# |! i8 G- ~& [/ ~9 F9 ]
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
2 h# W$ G, L7 f4 q7 c setup-intersections ^& F. C9 w! n! f1 P0 }- o, h
end
, }" S/ Q( ^# S0 [2 w其中定义道路的句子,如下所示,是什么意思啊? j% f2 [ d9 e7 E8 k% Z }& z
set roads patches with4 u7 j! S% p7 L
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or. w- ?. Y6 O2 w! y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 i/ O7 H# E- V1 U' Z
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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