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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 P5 L; b( z- ^. Inetlogo自带的social science--traffic grid这一例子当中,
, w6 H4 X4 I+ _8 Z8 Y' @globals7 s1 G% w V/ M: l* _+ y" Z
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grid-x-inc ;; the amount of patches in between two roads in the x direction2 M/ Z! W1 O" E; M7 X# B+ e
grid-y-inc ;; the amount of patches in between two roads in the y direction2 p$ L1 v$ p5 Y6 ~
acceleration ;; the constant that controls how much a car speeds up or slows down by if
9 v: f7 Q% `8 \9 f& h; l ;; it is to accelerate or decelerate; k l8 o1 C! Y6 s- O! |+ B
phase ;; keeps track of the phase
2 x9 j$ B4 v ^/ D0 _3 [ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure4 w; {, Y% F% b4 ?" l* L1 x" i
current-light ;; the currently selected light! b+ Z1 J3 t4 ^6 |: X( y: u0 |
: ~' |4 C$ c) t/ l, ?0 [+ g4 c" X ;; patch agentsets9 l* f7 c# K n% `! ]/ M- `( W: X
intersections ;; agentset containing the patches that are intersections' q3 D, n8 [3 T* k) x2 L
roads ;; agentset containing the patches that are roads( W( U; M6 O& y( Q2 F& j
]
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turtles-own3 ?- z! R% f3 ~, v& z o5 N
[
5 U9 d. l) B: }3 o4 B3 S speed ;; the speed of the turtle& X \$ ^+ L% v/ L6 R
up-car? ;; true if the turtle moves downwards and false if it moves to the right H6 i- J. ~+ L9 B+ ^: O
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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; a" O3 [5 k7 m% p3 N* \ intersection? ;; true if the patch is at the intersection of two roads# m) E$ G/ ~/ ]/ X
green-light-up? ;; true if the green light is above the intersection. otherwise, false." ^0 ~3 K M' N x5 E e
;; false for a non-intersection patches.
7 \( j$ { c. d6 v! J; O7 z my-row ;; the row of the intersection counting from the upper left corner of the7 d. E$ `. ] i \' \
;; world. -1 for non-intersection patches.8 J, N. d/ b2 l2 k
my-column ;; the column of the intersection counting from the upper left corner of the0 a. Y3 I2 A; X+ V9 G0 y0 B
;; world. -1 for non-intersection patches.4 P* v! {$ @& f* f
my-phase ;; the phase for the intersection. -1 for non-intersection patches., k+ `- g& w0 T* S7 b
auto? ;; whether or not this intersection will switch automatically.
5 z! b4 b9 u, u6 E ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
, h4 F( ]% v4 l1 b+ i+ P7 x;; Setup Procedures ;;+ b$ v3 J& Z3 _! i0 {* F
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;; Initialize the display by giving the global and patch variables initial values.
0 E: ]; W. e0 X) W/ P) r; x0 J0 i;; Create num-cars of turtles if there are enough road patches for one turtle to# ?+ m7 D8 a* b
;; be created per road patch. Set up the plots.2 R2 i0 @! K$ W
to setup
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setup-globals/ n8 X: h0 h9 y5 `# M( r, w
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;; First we ask the patches to draw themselves and set up a few variables
6 G: J! X$ S% b, T5 w' X9 U: c setup-patches
5 I, P9 m2 ^& } make-current one-of intersections
" [. R# L: L" A$ V3 m label-current$ b) p' p, {$ w% M+ F" G* F. m
) S, u/ }7 }6 Y- g+ @, P set-default-shape turtles "car"6 {/ h% N% L6 @% _! A& |
& @/ G5 G; V" g if (num-cars > count roads): o# E0 j0 q% Y& ^
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user-message (word "There are too many cars for the amount of "
; {) P( v; l2 B: _3 y "road. Either increase the amount of roads "
1 p$ O' ?$ i6 A# N: u+ S/ Z# T "by increasing the GRID-SIZE-X or "$ q+ u( \8 B$ b+ r8 _
"GRID-SIZE-Y sliders, or decrease the "/ c" }; l2 G% ?9 M$ q
"number of cars by lowering the NUMBER slider.\n"
, f i! u4 w4 k, x1 g4 d. J "The setup has stopped.")% e. H) w! |3 l2 a2 H
stop: ]4 y( X/ J# x2 W7 S
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
R. P* i" j* X# s crt num-cars" L5 w$ g' W% j. U4 {$ f# r
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setup-cars/ e4 [# j" N4 t {5 r
set-car-color
! X8 i; p" L# p0 X1 B& ?9 B record-data
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;; give the turtles an initial speed
; b$ v0 z& Q) X. Y8 n- c. }0 Q0 N ask turtles [ set-car-speed ]
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6 [8 {, P# ~& E4 M reset-ticks
) A8 O% y" k9 b% @! K+ uend
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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 yet
" h6 w; _# U( T4 [* C* {/ f$ @ set phase 0
; H! L$ ~. |3 U1 a1 U set num-cars-stopped 02 j2 |0 y8 Q* c }# D
set grid-x-inc world-width / grid-size-x
) @! E% w$ w+ N; m4 D, d set grid-y-inc world-height / grid-size-y. b1 O: N1 u( i2 A4 b
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
+ r, I4 Q7 c2 b) \5 U0 [ set acceleration 0.099
. D O5 j% S* |) Iend; g2 y7 ?8 }4 _7 z
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,* B9 R$ L8 m/ z# V
;; and initialize the traffic lights to one setting
4 ~) p7 e. d& n8 ]$ g# Oto setup-patches
; ^' m" }- h' @ ;; initialize the patch-owned variables and color the patches to a base-color
" P; I7 N& A8 a* q ask patches& }. O& S# @* K/ E
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* T9 n0 o. w2 d( L% n# v set intersection? false
# o4 U) X$ T, U, k5 y" { set auto? false8 a6 I* B2 y8 N! i! G* w& [" L
set green-light-up? true
( M p" Q% i- Y2 v set my-row -1
3 U! q% D# C/ A7 K! C8 `$ N set my-column -1
; D# J& o2 |# i4 Q* B set my-phase -15 k% ~ s- o/ `1 u0 R+ Y: A
set pcolor brown + 3
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, D4 D. R& p, q9 ]3 s ;; initialize the global variables that hold patch agentsets; _$ i2 }/ q+ u9 S7 a( v/ h
set roads patches with6 L# o! H" `: c$ N3 p& M# _
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or6 o/ D8 s+ [( c! O0 q5 |
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% Y6 m D; r3 `" n! l: M$ X( }1 a set intersections roads with1 ^3 b/ f5 |( E: o1 M
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
$ h* {, P8 }$ Q: \9 S, y! ~ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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; X) C$ }. Y Y% k2 _, Y ask roads [ set pcolor white ]) j! C5 a- p, t7 G. G6 f
setup-intersections
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" o+ c+ i; l# v7 O. `其中定义道路的句子,如下所示,是什么意思啊?
3 e1 E0 O& i# z set roads patches with
! _6 u: W0 t( t8 b! \ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, U: A2 b% S o
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]( ` j+ X( ]6 L2 W6 u
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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