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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。/ \" x4 `+ Q- x
netlogo自带的social science--traffic grid这一例子当中,; m4 _( ~* Z7 I
globals6 Z2 y8 U, {) }' V9 U7 w
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B5 x; _2 s8 R6 O grid-x-inc ;; the amount of patches in between two roads in the x direction
: k2 B1 H6 r4 j6 i+ Z2 o grid-y-inc ;; the amount of patches in between two roads in the y direction- O, ~% e8 O" h9 n' y
acceleration ;; the constant that controls how much a car speeds up or slows down by if
M9 F2 c; W! w O+ U" D ;; it is to accelerate or decelerate
4 [3 [9 M7 ]5 p8 G4 n phase ;; keeps track of the phase
3 q7 K1 }6 N6 p% F0 v& I num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
+ U3 Q+ x8 M! |/ n6 {- p5 } current-light ;; the currently selected light
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;; patch agentsets0 z i a, K8 Q4 l, m2 g
intersections ;; agentset containing the patches that are intersections
# W7 ?4 {* W3 N% ~/ V roads ;; agentset containing the patches that are roads
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turtles-own# A1 J9 `2 G7 q* Z" n
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* O# h! D% c6 P2 V4 }) ^ speed ;; the speed of the turtle+ Y( P. K: @, a; z: V7 S6 H
up-car? ;; true if the turtle moves downwards and false if it moves to the right
# M% O8 o) `6 [- ` wait-time ;; the amount of time since the last time a turtle has moved( ^/ v# e7 o- e* }1 X* G9 y
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patches-own3 V* j( F& A: `" z
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* G/ L+ i! Z3 R6 @2 C intersection? ;; true if the patch is at the intersection of two roads' q9 J# k2 I/ v- D; O
green-light-up? ;; true if the green light is above the intersection. otherwise, false.9 R5 ?1 @3 }" F' e
;; false for a non-intersection patches.
# Q0 A, y- T H" F my-row ;; the row of the intersection counting from the upper left corner of the" ~" h u% ?4 ~0 N$ B2 j
;; world. -1 for non-intersection patches.- Z- w; F7 {: s* b, @/ p
my-column ;; the column of the intersection counting from the upper left corner of the
- ~3 f( W* ?' ?* J) j ;; world. -1 for non-intersection patches.
2 y7 ?* O$ ?/ R. }3 V* l H2 ? my-phase ;; the phase for the intersection. -1 for non-intersection patches.; b5 M7 \4 `* I' A3 }
auto? ;; whether or not this intersection will switch automatically.
9 n2 F n* T0 t ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;3 }& E$ S* a+ t" B
;; Setup Procedures ;;
' k/ N& I. ^! A;;;;;;;;;;;;;;;;;;;;;;
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6 n) `: S, ^# ]" _3 P2 k;; Initialize the display by giving the global and patch variables initial values.
* x0 W* H9 x: r) E0 };; Create num-cars of turtles if there are enough road patches for one turtle to
! z& R0 s5 i# [; R" k; {! g( R;; be created per road patch. Set up the plots.+ T6 ?( f3 V" v7 u$ K
to setup
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# a5 I8 m7 I- X/ a( K setup-globals
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4 Z# w- O) g+ E6 @, i0 D ;; First we ask the patches to draw themselves and set up a few variables
1 s4 I I& C5 y setup-patches! B* B" Z' M. I4 H2 T
make-current one-of intersections" o! p. M4 g8 M
label-current
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8 @4 ?4 w7 U+ [/ b set-default-shape turtles "car"
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: y- z( U+ k1 C if (num-cars > count roads)
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$ q1 M" L, d- f m$ L user-message (word "There are too many cars for the amount of "8 l: a& t3 s6 [9 _4 ~& P$ A
"road. Either increase the amount of roads "
1 y6 ~+ Q: J# ?0 J "by increasing the GRID-SIZE-X or "7 Q X7 V; { l$ k: P' G
"GRID-SIZE-Y sliders, or decrease the "
6 @# B$ b+ u) G. Y. H5 D/ P "number of cars by lowering the NUMBER slider.\n"; e6 N: t; V* C
"The setup has stopped.")+ |: R' N& C# W$ ^! o! J* X! T
stop
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- h, `! ^8 S7 s) H ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color. O6 G# ^% L. }) o, K
crt num-cars; W! s% S9 o" ?
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setup-cars
# V* u) i m6 J. H2 H1 R* O& F set-car-color A& O6 N1 R8 A: t' g
record-data
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;; give the turtles an initial speed
, c* p% a9 u6 k; ]- e1 r/ ` W ask turtles [ set-car-speed ]
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! C* L1 W: S! i( u0 C) Y reset-ticks
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1 N' f* k. H( R! r8 x1 h;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet* q7 E* d) H! m, |3 S
set phase 0
# t; ]* T+ r+ j! K6 a7 R set num-cars-stopped 00 P1 X, B. q6 M/ W
set grid-x-inc world-width / grid-size-x( Q" f1 P, x. {& h8 c2 X8 {! F/ |
set grid-y-inc world-height / grid-size-y
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- }* Y. B: S# e2 T ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
. I2 r; o# B5 d& _( o$ l+ m- U set acceleration 0.099$ Y# v; r2 d: O5 k8 ]# j+ A* b! x" d
end. x t0 }3 G$ Y# ]" @
# Z, z# b0 n- \- I9 v9 f# I. t;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
6 I) n' V% d' `" s Z% I6 B( W;; and initialize the traffic lights to one setting
* s8 }% n* E0 ^* g% d( ]. g$ gto setup-patches
3 {1 K/ {1 Y2 O% f/ d/ ] ;; initialize the patch-owned variables and color the patches to a base-color
! z7 N2 K. T* x ask patches
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9 R5 i9 X, t1 E" F- `$ X# E0 v set intersection? false' U e' Q; s+ P5 [& d7 j6 s
set auto? false4 @# Z+ h* Q2 s& S* L4 m
set green-light-up? true
& ?0 k; }5 v% t3 X( e set my-row -1
3 f8 `. r% O" _5 B set my-column -1
0 t9 L1 N# | c% W! a set my-phase -15 {8 ]. w/ T% N
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
- C; r @8 W, V( Y+ B set roads patches with
& p. U, A" ^& e8 j4 Y# h4 v [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" ^* D' `% y, w8 J' p (floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 V& y" a+ |6 U* O; X6 C! e9 B8 h% h8 [ w
set intersections roads with- h* h4 _5 _! ^& h, y. g
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
8 Q7 T9 q. E5 t6 [; L) H* R6 f (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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/ Z8 n/ f! F4 @& `9 d ask roads [ set pcolor white ]( e6 B0 Y2 m/ c- e
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?6 Z9 x5 H- ^' ?/ k6 g' U& l8 q$ n
set roads patches with
' w8 l- `* b2 C/ U7 Q3 W0 x [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or/ Y, }9 F0 ?4 y3 Q/ h, N
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]; @" t9 v% |, A; X, \3 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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