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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。1 s4 M0 E, S/ [( i
netlogo自带的social science--traffic grid这一例子当中,$ X( x. m: @+ C
globals1 R: `: X% w3 z( m( l! B. M
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7 a' P" A9 z) r, j7 m grid-x-inc ;; the amount of patches in between two roads in the x direction/ d" Q" S$ S. d7 |
grid-y-inc ;; the amount of patches in between two roads in the y direction; S( b$ n6 L+ Y+ s, q% X! {! z
acceleration ;; the constant that controls how much a car speeds up or slows down by if
. P k0 n3 v2 _. @. V ;; it is to accelerate or decelerate9 b: _5 { q$ r f( e
phase ;; keeps track of the phase9 ^; P, ~2 F, M, P9 A0 G4 ?
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure" j$ p" ]7 f! q. b3 k1 o" v: K3 @
current-light ;; the currently selected light+ ~) B: f2 s( ?
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;; patch agentsets
) Z4 f# n( G/ Z; N; o' y intersections ;; agentset containing the patches that are intersections* {' _' C& g R, c" r
roads ;; agentset containing the patches that are roads$ H9 ~7 s B% ]% o7 P$ @* n8 f; Y$ g
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0 o' X J6 e3 N) Z6 e/ s4 xturtles-own
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% `! Z+ s$ j% W c; k5 j speed ;; the speed of the turtle
; _9 W& Z! o! X3 ]& D8 ]8 r up-car? ;; true if the turtle moves downwards and false if it moves to the right3 {* e0 K( O1 P) N/ q
wait-time ;; the amount of time since the last time a turtle has moved. [/ [* _, w1 r! \) g
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9 p& y' Z$ ^9 ] I7 b3 l3 Vpatches-own7 B* V5 d. A9 c8 ?+ @; l* N; M- C" q6 t
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/ P' S' @4 y0 ^6 S intersection? ;; true if the patch is at the intersection of two roads
; G% U. L% r# i$ t8 x green-light-up? ;; true if the green light is above the intersection. otherwise, false.( e" y. ]: D/ K$ Y# T- k
;; false for a non-intersection patches.8 h! t. a" \1 r/ H) b
my-row ;; the row of the intersection counting from the upper left corner of the
# c% s3 [% _9 ~- @: o" ` ;; world. -1 for non-intersection patches.
- C* x- }. X0 f( g2 ? my-column ;; the column of the intersection counting from the upper left corner of the F& O, P# X- A6 l# z/ n
;; world. -1 for non-intersection patches.# F$ @/ J( [. ^# M# j$ `
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
' ^* n( j4 I. p* A5 q2 a1 z7 C* m auto? ;; whether or not this intersection will switch automatically.) O2 u8 R+ Y% g9 l
;; false for non-intersection patches., s$ _# @, q+ ?2 f6 l8 C8 r0 Z
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9 Z6 c G' e" Z5 ^9 M$ X# L8 o) C4 [;;;;;;;;;;;;;;;;;;;;;;& U# W# {; u5 ]+ s8 G
;; Setup Procedures ;;8 q3 F6 } q. g9 ~8 k; o
;;;;;;;;;;;;;;;;;;;;;;! m3 `9 x% \3 E3 R* _# B
5 K+ s7 F' k" s; }/ o;; Initialize the display by giving the global and patch variables initial values.
' |, r2 j$ S6 f0 j4 a;; Create num-cars of turtles if there are enough road patches for one turtle to
1 ^4 R6 ^9 \& S* r5 M; W9 [2 h;; be created per road patch. Set up the plots.+ s# l0 Y7 X- Y# i
to setup
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5 s5 r& S( y+ C: Q) q: T setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
, a6 f7 {) f0 J! K) V6 Q( Y setup-patches
6 C. w2 G$ H0 h K8 A# R% J- p make-current one-of intersections
- U/ \, G- h: |+ u label-current& x- y3 O0 V4 r
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set-default-shape turtles "car", \! B. o" @9 e9 Y3 f; o. k
6 t. @( w) r9 J* ~7 F8 c9 H if (num-cars > count roads)
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* @( ^0 b& n" Y1 A user-message (word "There are too many cars for the amount of "! e: j( J* M9 F
"road. Either increase the amount of roads "+ t% m6 Q+ t& _6 U' V* O" K6 `' q$ l0 \
"by increasing the GRID-SIZE-X or "9 K. e. g: }- }1 q- x
"GRID-SIZE-Y sliders, or decrease the "% X/ k p: N; e3 u2 O7 K
"number of cars by lowering the NUMBER slider.\n" [- @ Y5 ?4 i, L1 e
"The setup has stopped.")
9 Z6 o) t. a7 _0 T! w3 L stop
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! M, _' d6 _5 p& J4 x0 [0 j ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color/ }& t" g/ _& A; Z7 y8 c
crt num-cars
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setup-cars; L0 v% r" ~- r0 ?% J: s7 ^
set-car-color
' B" M7 I) ^/ u record-data
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( t9 w8 u' p5 `5 b ;; give the turtles an initial speed
O {! h+ z& m ? ask turtles [ set-car-speed ]' g+ @% k. T, e w" X
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reset-ticks! p9 U; `( i. M
end F5 [2 S8 n" q8 C- M' y( M
( V2 X( B# J& E+ V' A+ ?;; Initialize the global variables to appropriate values
% ?* M5 J! _. W, }; N# ]to setup-globals
+ n- r4 O! f) Z- ^* q% @ set current-light nobody ;; just for now, since there are no lights yet! g7 Y$ Q/ k, ?+ t9 q+ _
set phase 08 Q1 f0 J, P2 E3 Q
set num-cars-stopped 01 \, Y- @( k' i: r0 G4 J: m) U
set grid-x-inc world-width / grid-size-x2 B4 m& x, ]8 N1 I( H
set grid-y-inc world-height / grid-size-y3 I' ]6 K2 y0 y$ C u+ U: Z
W/ R: E% y: Z/ N i4 x. S ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
% M+ N& a& H8 W, ^0 ~! A2 ] set acceleration 0.099
9 y5 E- p$ X" D( }: |end; l" N3 b% r2 Z" ~$ x, K/ N. e% y1 w/ N
, d' A/ T8 {( x5 z, e% D, A6 _* B;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
0 @" v4 N9 p1 W. }# M3 w2 z;; and initialize the traffic lights to one setting) t" n8 N6 m) x: p+ q/ {
to setup-patches
' P! N6 i& @( y; M ;; initialize the patch-owned variables and color the patches to a base-color3 L& d; p' Z. ~+ Z" Y! `
ask patches/ v7 w Z2 T9 |% r. n& h
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set intersection? false" S3 O( f9 Q" S' [
set auto? false" o& X* Q7 \; d' ?
set green-light-up? true
) S; Z! G! j% ^2 |0 h set my-row -19 n: f% ]; Y' S t3 }: h
set my-column -1* L# @( S s ^9 o
set my-phase -1- _) j) I* v6 L/ f. o
set pcolor brown + 3
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7 p/ [+ j$ @; Y0 u$ S, Y ;; initialize the global variables that hold patch agentsets
/ R& H2 y# c0 \5 R+ O set roads patches with- n' f# Z8 R8 N$ B
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
. e" i8 _$ T/ T7 \ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 k: \; v( T/ P2 b9 f& c; o set intersections roads with
( x: j; p/ T9 x+ r1 q3 |9 G [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
, C& x: I! `% { (floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 ^9 p8 S1 {: u ?8 Q, ]/ Y9 [
6 i8 C% t2 {$ _: v+ w, a& j5 l ask roads [ set pcolor white ]
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end. }" `( j2 _2 G$ Q4 }5 L; h
其中定义道路的句子,如下所示,是什么意思啊?
: e4 j0 S7 S/ ^) n: a2 n set roads patches with
) k8 O3 e) ~6 w6 H [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or. y% s8 n% D" }' p
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]: H/ k# l* M3 N# h' 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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