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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。( x: I: V0 s# k: F
netlogo自带的social science--traffic grid这一例子当中,, ?9 @. a& b+ Z2 q! n
globals( b# n1 I6 n% j9 t0 l9 n5 ?
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grid-x-inc ;; the amount of patches in between two roads in the x direction8 m- E" w' u0 z; q4 r0 h* Z# G# n
grid-y-inc ;; the amount of patches in between two roads in the y direction
6 D7 Q' V( s7 i7 b# F/ V8 J acceleration ;; the constant that controls how much a car speeds up or slows down by if
' B" H6 E* Y! X+ q3 h ;; it is to accelerate or decelerate" @ U. b4 g' N8 _& D
phase ;; keeps track of the phase; I7 f* t9 [% @* S, i
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
! N& H% m X5 B( Z% `9 P2 S* m* _ current-light ;; the currently selected light
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;; patch agentsets( d- H" I# M5 z) F
intersections ;; agentset containing the patches that are intersections
* D, d$ K! K) a$ {% f- W& i roads ;; agentset containing the patches that are roads( U9 t8 K: ]* y" j# G2 r
]
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turtles-own
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. h* n" q, V6 k6 ~8 j1 T& ?/ _ speed ;; the speed of the turtle
" J* o+ Q2 a* V$ w, {$ U ~0 C up-car? ;; true if the turtle moves downwards and false if it moves to the right
0 |$ ^4 X! {, u2 Q0 F wait-time ;; the amount of time since the last time a turtle has moved; M" ~ c p3 r8 ^* d1 _
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6 ]- G. r( `8 w8 T/ v. _) @" Gpatches-own
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intersection? ;; true if the patch is at the intersection of two roads" B% U# m. N. b) S' P
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
9 b. k9 O% H. N% h+ j" d ;; false for a non-intersection patches.
# O3 \0 j3 Z6 Z my-row ;; the row of the intersection counting from the upper left corner of the' z6 O: n% f5 ~6 d% |, y
;; world. -1 for non-intersection patches.
: A# o" z- K6 y" n5 o+ G0 c9 ?# i my-column ;; the column of the intersection counting from the upper left corner of the" A$ |" R& ~6 r9 s+ {1 d4 J
;; world. -1 for non-intersection patches.
; @: W" i# H: |6 O4 H! p& Y my-phase ;; the phase for the intersection. -1 for non-intersection patches.
9 |5 s7 N/ Z; D$ L% L auto? ;; whether or not this intersection will switch automatically.
& L7 U# f2 }9 _2 }: p/ [ ;; false for non-intersection patches.
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- [# `4 }* ?1 ?8 A |$ K;;;;;;;;;;;;;;;;;;;;;;1 g4 {* n( T& U3 V& X0 z; z
;; Setup Procedures ;;6 D# N3 S/ {" J
;;;;;;;;;;;;;;;;;;;;;;
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( N; C& g- z. z' m6 v. a5 h;; Initialize the display by giving the global and patch variables initial values., L" A& g8 g9 l4 m& c4 {3 \; {
;; Create num-cars of turtles if there are enough road patches for one turtle to- V2 U/ z$ _8 _# w& E
;; be created per road patch. Set up the plots.
" }" c" O3 x5 e: H# Jto setup, |5 [' f( S: \ P. d% P% k9 p
ca
& ?( R# X( u4 b8 g! Y& @ setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
! F$ E9 S7 q/ F( ] setup-patches( \# c" X$ m7 d# B$ n
make-current one-of intersections
p" e0 W+ w8 `$ W M label-current. G2 t7 M* l S$ q4 [ W& a
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set-default-shape turtles "car"! q4 y, X z! Z! D
) h' s' u t8 W if (num-cars > count roads), k) {5 L: b" j& S0 k: U
[
6 P* r9 _$ C' L3 A4 ]0 e5 A user-message (word "There are too many cars for the amount of "0 _1 G5 s0 _3 y6 P
"road. Either increase the amount of roads "& }1 C' F- j% M& @
"by increasing the GRID-SIZE-X or "
4 j1 w3 K0 |4 o "GRID-SIZE-Y sliders, or decrease the "6 t2 [. _5 \$ j- v; A3 t
"number of cars by lowering the NUMBER slider.\n") g7 E& e% K0 J* D& O9 X& Z
"The setup has stopped.")7 D2 r+ [- N6 }4 A' B8 \' h5 K
stop
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! N4 ]* b* w7 C ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color( H; M! U# {+ h. b! _( E; `
crt num-cars. D8 m4 w7 P. M0 r6 l0 q+ W
[
! K* \5 Y$ H) h, Q) x setup-cars
2 b( y6 ?+ V8 y6 e2 q set-car-color
- B. Q3 G6 @4 Y# K& Y record-data0 _; D5 a9 A; c6 Z8 s8 M- G/ j
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;; give the turtles an initial speed
7 c$ z s c$ j% \% \ ask turtles [ set-car-speed ]
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reset-ticks) h+ Y4 g2 T( `$ T/ N& n9 T0 f
end
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2 \! c- v2 o1 R0 m" r$ a7 T; L$ b;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet2 K4 f7 L- [4 k# d. v! J* m
set phase 0
% e2 o0 F3 Q5 ^; m; h3 a set num-cars-stopped 0" \# l" M- s, ]/ _2 J$ A
set grid-x-inc world-width / grid-size-x
# z$ t ]$ V: G* C! a: U& Z set grid-y-inc world-height / grid-size-y
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4 ~1 O! I, |" q8 z: e; l) Z ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary# |! g }1 T% |6 M7 F$ M
set acceleration 0.099' T1 j0 V0 _" P% q
end+ W3 Q3 M4 K: Z. T/ s2 E
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,% Z% k S/ F* L2 y& r" [/ r
;; and initialize the traffic lights to one setting
" y5 b W- s' l0 U9 ~9 h9 C0 ]to setup-patches) u, Y' D0 Q: j
;; initialize the patch-owned variables and color the patches to a base-color6 A! j F2 a5 m# S. T
ask patches/ D4 y4 ^0 G8 l) j5 ^
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set intersection? false
5 `8 Y% ]9 w- s* @% w1 X/ ] set auto? false1 j- p, ?- O5 T! D6 _4 Q
set green-light-up? true
$ I) d) V9 m9 s; M O: Y set my-row -1 J! ]6 l8 C" [3 r) M
set my-column -17 x8 j9 ~4 H3 ~! [# R5 C8 p
set my-phase -1
( h& N$ r% @, C! `+ L. P set pcolor brown + 39 u/ w3 M0 ^5 {( n' F' b
]
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0 h0 q1 w, @' @; M ;; initialize the global variables that hold patch agentsets
8 [9 W4 N+ w& F0 M set roads patches with* N* o" _+ b+ u/ `$ M* P1 w
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or- y6 N, g7 o7 K! ~2 y, e
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' F! v- T5 w' k! A4 E# G set intersections roads with" z# l7 U# o" c; g b
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and+ O6 k# a: }$ B/ G5 h3 z5 V1 H
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]" h4 [! W6 T& V4 _
0 j' [+ D0 o2 x ask roads [ set pcolor white ]! ], y* [3 J8 }) T
setup-intersections
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# d7 m G# U8 ? v+ j其中定义道路的句子,如下所示,是什么意思啊?
/ `# {' Y; V* F3 n6 ?6 t& @ set roads patches with5 J* @% |1 l7 x2 d) T. C# x
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' E+ F: j G" p# _ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 q# ~; G& K5 d i9 R$ 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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