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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。$ _8 t+ U( i5 u/ S! Q, `/ Q" {" `
netlogo自带的social science--traffic grid这一例子当中,
8 l* b _3 c/ j4 @+ b& fglobals) m. e0 V& q6 Z5 Z
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4 M3 s( a; i- \- V T grid-x-inc ;; the amount of patches in between two roads in the x direction
) E% y; v# [ a: _7 Q- u% Y grid-y-inc ;; the amount of patches in between two roads in the y direction
8 w4 {8 |! ]* P N acceleration ;; the constant that controls how much a car speeds up or slows down by if
# |1 o# p, j2 a+ r; a: Y& v ;; it is to accelerate or decelerate$ c& D9 k% U0 s3 a* R! O$ s
phase ;; keeps track of the phase9 F2 n. h' J: Y( _2 U
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure4 q- ?# k3 g+ P
current-light ;; the currently selected light
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! v+ _8 \1 Q m c ;; patch agentsets- v/ W! w6 \( ?8 _" S @
intersections ;; agentset containing the patches that are intersections
; P+ J/ U5 K6 y% S roads ;; agentset containing the patches that are roads/ M3 w$ c p8 P: Y
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turtles-own" X4 c. l0 ]- V
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speed ;; the speed of the turtle
: _8 N' Z$ t- h, r. G/ f( n* x- ] up-car? ;; true if the turtle moves downwards and false if it moves to the right3 b# R9 ^+ a; O8 y2 I8 ?" [
wait-time ;; the amount of time since the last time a turtle has moved$ J* L! L+ g4 l9 p' X2 A
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patches-own
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, p! E u2 S; p* k intersection? ;; true if the patch is at the intersection of two roads
_8 z1 c- x. K1 P8 p8 F' a green-light-up? ;; true if the green light is above the intersection. otherwise, false.
" ~" ]- L9 R( V |4 X; Q7 p5 ? ;; false for a non-intersection patches.
0 [: L; O1 r3 c: n) \! R my-row ;; the row of the intersection counting from the upper left corner of the
; a; T- z5 W; Q' B% k ;; world. -1 for non-intersection patches.
6 i$ O5 Q( }/ y2 x6 {( J my-column ;; the column of the intersection counting from the upper left corner of the
* q+ K8 n8 a2 o3 a. t ;; world. -1 for non-intersection patches.
: u( Y* c$ K" U5 \& @2 G% F my-phase ;; the phase for the intersection. -1 for non-intersection patches.
: f# `* V2 I9 f$ ^6 p7 ` auto? ;; whether or not this intersection will switch automatically.- S# b1 ~ c- S/ K& ?* }/ u
;; false for non-intersection patches.
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8 G8 P2 h6 [# L8 i. T. M& p;;;;;;;;;;;;;;;;;;;;;;+ P. ]) l7 U0 H# r/ o
;; Setup Procedures ;;
" b/ z$ u( M0 [( ~* [) };;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.( l; f7 [6 O" k7 C
;; Create num-cars of turtles if there are enough road patches for one turtle to7 b( L2 U8 p* e! H
;; be created per road patch. Set up the plots.8 K& u r( W' L$ a, @
to setup
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setup-globals
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# |& t$ o3 ~( E' E6 o ;; First we ask the patches to draw themselves and set up a few variables
0 @$ Q1 \$ a8 ?% T& N. w3 | q5 ~ setup-patches
; i& R, g6 W+ v ^! e8 y7 j" l make-current one-of intersections8 b7 u! D: j+ N% }5 T( Y
label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)1 _! \& ~- J2 ]9 E* d8 i
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user-message (word "There are too many cars for the amount of "1 I. ~: s, V( D( t
"road. Either increase the amount of roads "
. N: k: ?" S7 R! Q "by increasing the GRID-SIZE-X or "
. D! Z3 |0 e$ W# r* o2 { "GRID-SIZE-Y sliders, or decrease the "5 g1 N6 l/ R7 k* Q
"number of cars by lowering the NUMBER slider.\n"
# I- X4 d/ a. U: J( l' x% ] "The setup has stopped.")9 F- T- L" V; Y0 @. C4 Y; Y$ {
stop2 k' l( ~+ i$ @3 {! l/ b& T
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N/ J1 u2 {4 m0 u& E ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color5 r$ }) j- T0 q
crt num-cars0 R \4 o( ^# f9 D5 @- \
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setup-cars
. X) D. ~. a- A# [& l4 q set-car-color1 C( b) R2 i2 k3 |$ A5 v J
record-data9 j" n5 C. r* F4 h
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3 D! d( z, y8 j ;; give the turtles an initial speed! f% f1 L" n) i! j( w
ask turtles [ set-car-speed ]
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. p3 _* T% X; P6 M! i6 d6 ~ reset-ticks
, _2 k' h6 g5 f, o* _end, A8 [/ G4 ?9 X6 ?8 k, z% i
2 K% S1 I( q. s/ y9 q6 y+ {# v, V+ {. Z;; Initialize the global variables to appropriate values k/ l3 [9 j. `" B. Y
to setup-globals
& q1 v P: N1 W" G+ z set current-light nobody ;; just for now, since there are no lights yet
6 F! _2 b. j- f0 u; Q set phase 06 Y$ {* B% @2 ~
set num-cars-stopped 0
8 v; a3 T/ Y, z% }( U8 h# b9 n% E set grid-x-inc world-width / grid-size-x. [. m' {8 J9 |/ E( M
set grid-y-inc world-height / grid-size-y6 P3 t. [6 r8 E( ?+ z0 T% 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
[3 l. ^0 O; {3 K set acceleration 0.099' I' p: t6 x* Y* T! V
end
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# i2 [; @3 |9 b;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
" n/ m) I2 U7 D4 };; and initialize the traffic lights to one setting
5 p" |' U( e: {! O% F: U' j! T% k: `to setup-patches: ?( G$ `, A6 p! v3 v% n
;; initialize the patch-owned variables and color the patches to a base-color; | H/ T# i8 r% N8 H3 c% Y
ask patches( G+ S7 D/ I% R$ m O
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set intersection? false+ x- q: F% A6 }2 g) ~! n
set auto? false6 V3 z: I c% ]$ {$ [
set green-light-up? true7 | k: F* |; a" ?* |
set my-row -1/ L8 B, v' ^0 |( T! F6 M& ~) i
set my-column -1
- J/ f4 N* v7 r! m" ? set my-phase -13 m/ m) e3 p0 Q. p% [
set pcolor brown + 3 I& n$ y! w/ j& K; r# K
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5 g' i0 _$ t g# o2 n+ S7 s! o/ b ;; initialize the global variables that hold patch agentsets2 Y$ J3 ^$ G- v
set roads patches with
3 N4 ^( \) P; z3 \' S6 k9 f' { N [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 L/ j0 {5 \# @8 F- P/ x (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ I7 ]- J+ `- `) z; U9 z set intersections roads with
6 n: P/ c* p1 ^* z0 E [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
+ Z/ W* ]3 @1 d j6 K3 x k b' n. F (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
( b/ S3 }8 p5 ~& i) q* k5 K! E setup-intersections
3 p2 N7 y) Q* R3 g" c5 r7 }% Iend
! c9 s8 }5 `% X6 ]) f, M其中定义道路的句子,如下所示,是什么意思啊?
' D5 _4 i- `4 w# @ set roads patches with
M! Q8 k0 a! K5 O$ S [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
, D4 [4 [; g' I6 U# J# Z3 r (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* U8 Y4 J6 B# ^; T) S4 s& v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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