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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。$ j' N1 j' u" F; g- u
netlogo自带的social science--traffic grid这一例子当中,, c2 j4 A4 s$ J
globals
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& g. N0 L* n8 \# c0 F grid-x-inc ;; the amount of patches in between two roads in the x direction
D* t8 Y9 l; v4 C4 A+ J grid-y-inc ;; the amount of patches in between two roads in the y direction
- ^. \) R5 _' H, B! ?7 ~ acceleration ;; the constant that controls how much a car speeds up or slows down by if
& i$ `5 S* k7 G8 F$ S2 N ;; it is to accelerate or decelerate
1 }% w3 D: F4 O# K" C/ C7 B% m p phase ;; keeps track of the phase/ r9 C5 S& Q. D4 a% x# g
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
, _: }* p* I7 I+ y current-light ;; the currently selected light
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0 x) m* h. N- M ;; patch agentsets" h0 {' C8 |8 t8 ]
intersections ;; agentset containing the patches that are intersections- N6 C: w7 n) h: A% i2 }' h
roads ;; agentset containing the patches that are roads
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9 ~/ x9 x7 m x; c% F) vturtles-own
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( r5 H) v. }7 T$ n; ]# k2 G speed ;; the speed of the turtle
$ k3 G4 {# {- |8 ?; b up-car? ;; true if the turtle moves downwards and false if it moves to the right% G: d. I. O( O/ h$ l- F% O
wait-time ;; the amount of time since the last time a turtle has moved
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9 l; }2 r4 B7 `$ n4 _patches-own
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) h: B# i4 h& |% \) {7 h+ h intersection? ;; true if the patch is at the intersection of two roads f; \0 l; |* x1 J- |
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
4 W+ v2 U( A8 x( Y! M. { [) W ;; false for a non-intersection patches.2 h5 a! r: s( v
my-row ;; the row of the intersection counting from the upper left corner of the W% g# i; Q/ ^9 Q
;; world. -1 for non-intersection patches.; I& @5 ? r; Z- h) f4 H+ M
my-column ;; the column of the intersection counting from the upper left corner of the: l j/ Z q1 v1 ^
;; world. -1 for non-intersection patches.+ O% y( a5 z8 o% a4 j: I, c) o
my-phase ;; the phase for the intersection. -1 for non-intersection patches.; x3 P" L% H' N& q @9 U1 v! n
auto? ;; whether or not this intersection will switch automatically." }: N, a( _' n" y0 t
;; false for non-intersection patches.! {- K# }$ W8 s4 |7 C# K1 X
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;;;;;;;;;;;;;;;;;;;;;;
1 S0 I! @! ? l3 L;; Setup Procedures ;;: m7 C. i2 R6 f" L2 O/ }
;;;;;;;;;;;;;;;;;;;;;;
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* J+ n1 C$ r8 z6 m7 Y" X7 v/ T2 b;; Initialize the display by giving the global and patch variables initial values.
# g6 h& e- n4 z;; Create num-cars of turtles if there are enough road patches for one turtle to
8 {9 Z [6 a2 i" T0 R;; be created per road patch. Set up the plots.
1 }7 z( A, C3 Wto setup# {& j3 I% {% B" k
ca
: u8 U, r1 a6 t& a( ~ ]5 T# C2 x; Z setup-globals
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;; First we ask the patches to draw themselves and set up a few variables4 G9 p# _# V6 Y; R3 _
setup-patches
' k7 g0 i) K/ } make-current one-of intersections% i! G' u Q1 r! d3 ?2 S8 M
label-current
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2 V$ _/ g* G5 y2 G set-default-shape turtles "car"4 @# G* B4 d$ l4 {8 l
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of ", [6 _( m( {4 Z, P; s7 ~5 L
"road. Either increase the amount of roads "
" t: M, `% l% R: Z9 E "by increasing the GRID-SIZE-X or "' E" P/ m5 ~, y# C1 K( b& J
"GRID-SIZE-Y sliders, or decrease the "
8 l; I: d! u% k* {5 ? "number of cars by lowering the NUMBER slider.\n") Q1 m5 J* `, u+ A% `
"The setup has stopped.")
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]
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color% m$ c! _8 ]1 p; m v" Y% `
crt num-cars
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1 `0 ]$ a0 l# `& [ setup-cars
4 u3 Q% S* o* k7 k# U6 b: ] set-car-color5 M) ^6 n }7 w' c
record-data# x/ w! ~ z% N+ `& {( G! Y" V
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;; give the turtles an initial speed- ? K# E! b! B
ask turtles [ set-car-speed ]
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reset-ticks
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' ]" B# N) L+ [# m9 G6 b7 ^" q3 Z;; Initialize the global variables to appropriate values, _1 C. w8 {- j7 o' v5 X
to setup-globals
. c9 I( T# f: Y' ] q% m4 n set current-light nobody ;; just for now, since there are no lights yet7 `* O9 L8 z8 B* P
set phase 07 b& Y" c# h- d
set num-cars-stopped 0, c5 B3 l" b8 ~7 b
set grid-x-inc world-width / grid-size-x& {0 I' T$ A7 F. J" `/ @9 \
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! `4 i0 c( \. D) m+ }" c m
set acceleration 0.099
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. @3 J- i3 K: c ?8 m4 k; d$ I8 v;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
6 a% S2 s: [( g;; and initialize the traffic lights to one setting& c2 K4 P5 ]! ~7 V' n& u
to setup-patches
( o4 V# ~" s( v; O6 s% } ;; initialize the patch-owned variables and color the patches to a base-color* p/ d$ K, X+ _; {3 F4 P- C
ask patches8 D0 g4 \8 S! L
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9 X( r% A, A/ m( l set intersection? false
2 v# c% t4 D/ ] set auto? false
- l# u) `5 D z. E `3 W set green-light-up? true
& k6 I0 _+ t! o# m set my-row -1
, v. c, ~; f. H% y5 @, M4 t% g set my-column -1
3 y8 ? h4 m* v8 ` set my-phase -1+ J h+ h: K+ l0 X, f8 ~9 U9 k
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
1 B/ l' t) p6 t' M2 _" d" k set roads patches with
/ R( X1 w) a. D [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
c9 O1 y: q" C. s) j3 | (floor((pycor + max-pycor) mod grid-y-inc) = 0)]& h$ U5 C/ \0 d0 i" c" I: A2 E
set intersections roads with
2 I% E* g2 R3 ~$ o/ @ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
. M/ S6 n p5 b (floor((pycor + max-pycor) mod grid-y-inc) = 0)]) ~7 V# u) Y' N& k# ^; K$ D! Q
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ask roads [ set pcolor white ], Z% J% A( h# M4 Z
setup-intersections
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( q) F- G" X& s4 j8 d# L( r5 J其中定义道路的句子,如下所示,是什么意思啊?5 Q8 C5 B3 l$ P$ q* I0 o- \
set roads patches with
- Q/ [4 q" o: J: r [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# i9 d* N4 |* u' `' y L+ g (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 h0 n6 H. u3 P& p& e1 G' G Y* M, {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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