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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。4 H2 y3 U( o' n6 e2 Y/ A% z
netlogo自带的social science--traffic grid这一例子当中,6 L; a4 f u3 L7 |0 m
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
+ I3 C7 S7 Y2 m6 y# A grid-y-inc ;; the amount of patches in between two roads in the y direction$ c/ p2 n" l3 j& N- w: i) B" c2 w
acceleration ;; the constant that controls how much a car speeds up or slows down by if# a: K( y% z5 u+ n
;; it is to accelerate or decelerate
* \8 X* c8 U- l phase ;; keeps track of the phase$ \7 d: ~7 {4 m R; p' ^3 T
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
1 s) |- M/ u. [5 o: r' y current-light ;; the currently selected light( |, N% v8 y- k/ O" O% E
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;; patch agentsets& U K5 F. F( n6 y: m+ F
intersections ;; agentset containing the patches that are intersections
- q" C% e# V0 [ roads ;; agentset containing the patches that are roads
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' t: p- r/ G9 wturtles-own
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speed ;; the speed of the turtle9 E" m% J1 ~: p* q
up-car? ;; true if the turtle moves downwards and false if it moves to the right5 e, y$ p' P$ f* Y2 q; X
wait-time ;; the amount of time since the last time a turtle has moved
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; H. N6 e. N( h2 Wpatches-own, V0 g1 K% w' i" J6 i
[
3 i. u! w; S8 m, W intersection? ;; true if the patch is at the intersection of two roads8 R: D) P( P0 B+ W; k: f
green-light-up? ;; true if the green light is above the intersection. otherwise, false.) ?" S7 a3 b- M1 {0 U
;; false for a non-intersection patches.9 y7 {) G! h" X5 \8 P/ {3 e
my-row ;; the row of the intersection counting from the upper left corner of the' ~* X2 V3 ]0 k. M" m: i
;; world. -1 for non-intersection patches.
5 ^; K5 c2 t# O2 t2 g" d; f my-column ;; the column of the intersection counting from the upper left corner of the
+ H( I% N% \8 g, H" f# I% c ;; world. -1 for non-intersection patches.) g* H% F! k* e! r: V
my-phase ;; the phase for the intersection. -1 for non-intersection patches.0 t, X' V. Y' t( i3 G
auto? ;; whether or not this intersection will switch automatically.
" m5 ?, r# I! K: ]" p ;; false for non-intersection patches.
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' s, @9 z+ T& X1 }0 R+ h# N;;;;;;;;;;;;;;;;;;;;;;
3 r& b! b: B' n5 g; J) d4 g7 f1 e) j% \;; Setup Procedures ;;
4 u$ I) Q* C: l7 M9 Y, l' e5 S;;;;;;;;;;;;;;;;;;;;;;) T! ^6 j6 ?! z
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;; Initialize the display by giving the global and patch variables initial values.3 i! n6 H9 s* L! D* m
;; Create num-cars of turtles if there are enough road patches for one turtle to
- [! h* Y2 G3 i3 S0 O1 Q;; be created per road patch. Set up the plots.; Q" M2 j: L; D! U7 Z
to setup
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setup-globals# K7 m( t$ r" m! }" s
1 \; W2 L1 E! I- j/ X& y8 |: d ;; First we ask the patches to draw themselves and set up a few variables2 J7 ]) L; v4 t- V* P: s8 \8 A
setup-patches
! b* r/ G6 n( |( Y. S make-current one-of intersections
5 V( ^# o. ^' [4 A# Z label-current
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. J2 d0 r6 B8 l; f, E/ y/ Q# K; o set-default-shape turtles "car"
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; c/ d, y8 @2 Q% j2 X if (num-cars > count roads)* l% E8 {6 G# ~- e5 |, B
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user-message (word "There are too many cars for the amount of "2 G2 m7 s; P: J1 u5 k" K
"road. Either increase the amount of roads "8 j' s3 ?; {* y9 X9 ?! g1 @
"by increasing the GRID-SIZE-X or "; K3 {* y( W( `3 r) E% n& \
"GRID-SIZE-Y sliders, or decrease the "
) b, O* O/ f$ o& s( O e P/ I* L "number of cars by lowering the NUMBER slider.\n"
) }" C( y1 V- p8 @ "The setup has stopped.")5 V2 W9 U' b8 j( v- o5 s# g; V
stop; L$ W* Q- U. y
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color# m/ l& @; f3 f& ~5 C7 h& {8 h U
crt num-cars
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setup-cars" |9 S; f3 H' [3 ^* m& {" {5 N( X
set-car-color
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]
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;; give the turtles an initial speed
+ }/ t7 j+ S+ M' E ask turtles [ set-car-speed ]* {" A8 T. _' w+ T# k6 }
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reset-ticks4 ~5 f# b( `) \: }6 `! N; h
end
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet0 ]9 s) N& p6 \! F4 V* ]
set phase 0& P! s. e$ c+ ]( R. K% Z, ?
set num-cars-stopped 0
8 S6 b8 L0 C# Z" y" q; ^ set grid-x-inc world-width / grid-size-x
) Z7 F* e7 C+ r& @3 X% y set grid-y-inc world-height / grid-size-y+ @# S1 w9 ~# q9 Y/ h# L6 g
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary/ M7 N1 Q0 j% z4 Y
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
7 j+ l `; f' ^ q6 ^) s; `2 m' e;; and initialize the traffic lights to one setting
A, A6 @- M1 f' Nto setup-patches
0 w0 Z/ @; S9 d0 A, f: R ;; initialize the patch-owned variables and color the patches to a base-color
/ y5 k: x. o! ^ ask patches
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; F$ L7 h0 U$ D, Y9 S# d* \, _, _ set intersection? false
5 f' T3 h# R2 H7 S! e7 T set auto? false9 D3 r0 J6 b4 c X# W! ~
set green-light-up? true% _& z7 ~. U0 e; K5 s: a; w0 m
set my-row -1+ L5 F0 e( a' g, }, I
set my-column -1
. a% \- M2 A. t: S set my-phase -1. _1 e4 W5 u1 @) G0 C& a
set pcolor brown + 3
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' O( i$ e/ [8 I v6 t ;; initialize the global variables that hold patch agentsets+ O0 X2 V6 c3 [6 V* D p6 z& i( o
set roads patches with4 h+ a' h6 K6 k) ?1 h: f
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! W* y) Y$ B+ I4 U3 j
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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8 x& Q# i4 ^* p ask roads [ set pcolor white ]
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其中定义道路的句子,如下所示,是什么意思啊?
# d/ p( q* W" m! u( m7 v6 o' f5 J set roads patches with
. }/ K" s5 U7 q" Q5 t [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or; L4 u4 K" _, u7 b2 `% o
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 _# z' Z( {: R5 N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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