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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。( {- r; R0 ~1 ^/ k, k! a \: l. A* R
netlogo自带的social science--traffic grid这一例子当中,( z7 [% E T# M6 v
globals; Y/ a* |8 D# p+ S! y8 H
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grid-x-inc ;; the amount of patches in between two roads in the x direction
8 Q! q" t1 a; N% h2 x: Q grid-y-inc ;; the amount of patches in between two roads in the y direction" L$ A e# o& ]1 n: t' r
acceleration ;; the constant that controls how much a car speeds up or slows down by if! k4 s: M, K, I0 H7 W
;; it is to accelerate or decelerate8 z8 Q5 o0 M$ A( b6 H- c: n
phase ;; keeps track of the phase+ ~3 C2 W. v: A# i3 U
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure2 X* W, \! ]8 }7 j5 m# j6 q
current-light ;; the currently selected light
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;; patch agentsets& z) h ?6 b6 I& x* S: ^
intersections ;; agentset containing the patches that are intersections
5 t$ r$ x& w" K6 G7 S' h9 N roads ;; agentset containing the patches that are roads
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/ V/ K( N3 U% Xturtles-own
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$ p) A, e/ u X4 J9 w7 o speed ;; the speed of the turtle
( ` b' D o3 `) w- d: @' D up-car? ;; true if the turtle moves downwards and false if it moves to the right4 w2 N. c) }' C' _
wait-time ;; the amount of time since the last time a turtle has moved" m: |9 x/ k8 ~) M, K
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
- z6 B5 A3 U+ s* n/ M# B1 X. w green-light-up? ;; true if the green light is above the intersection. otherwise, false.) C# z) q0 w; Y+ q0 p% ]
;; false for a non-intersection patches.
3 m# `; P2 n6 [ my-row ;; the row of the intersection counting from the upper left corner of the: K3 B v y$ Q1 A5 \" O0 ^
;; world. -1 for non-intersection patches.: l; @0 `) w+ j
my-column ;; the column of the intersection counting from the upper left corner of the& u- ~, z$ r, L, r# u9 J
;; world. -1 for non-intersection patches.
- S0 l& S( g9 S4 Y3 L1 { my-phase ;; the phase for the intersection. -1 for non-intersection patches.
# R# e+ a+ f7 H auto? ;; whether or not this intersection will switch automatically.
" N. t6 C0 Y' j4 `% [# N ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
& d) @# O+ h- Y4 V4 a;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.+ ?5 g% e/ ~# I- f9 C) b: Z
;; Create num-cars of turtles if there are enough road patches for one turtle to0 |$ C4 m1 R& j
;; be created per road patch. Set up the plots., I* B# v* d; Y- {2 D! J E& j7 _0 y
to setup
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% j" t/ ? N7 Y+ ^0 l/ s setup-globals1 f6 a! g+ B# b7 ?" X! `* [8 H! ~/ @6 M5 L
6 q _* h8 @ Z Z' N& x ;; First we ask the patches to draw themselves and set up a few variables3 ?* T8 E" K, t" z2 w
setup-patches4 o2 x9 D9 l! I* n8 y& {0 f, T
make-current one-of intersections
+ F; a+ i( g0 [( ?4 e4 I label-current' y# L) w3 `; C
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set-default-shape turtles "car"
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9 U* P$ }( h# M; S& H, N/ u) w if (num-cars > count roads)
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; K& `3 Z2 H- l# ]% M$ O* ~2 g/ C user-message (word "There are too many cars for the amount of "
! F4 ]' D. h$ @9 @ "road. Either increase the amount of roads "
% l% q% E D( N6 @& F "by increasing the GRID-SIZE-X or "0 X( h$ H; V( i! i% D
"GRID-SIZE-Y sliders, or decrease the "+ J. Q+ n5 G2 h6 }' _
"number of cars by lowering the NUMBER slider.\n"
( K8 G1 ^8 w* d+ u, S7 `) L' c "The setup has stopped.")
/ S+ ^/ B8 [5 _8 f! |; A stop
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/ P; s4 O8 D- J y& ^ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color8 ?% W, D) `+ A4 ?7 R
crt num-cars
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& i( H5 g! J e# Z3 w) b; c& h1 H5 F setup-cars
2 @/ [9 w5 N% t j2 v" } set-car-color
- n+ Z# s) v i8 {& v( M record-data
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;; give the turtles an initial speed
% t! ]8 a( h, M5 ^ ask turtles [ set-car-speed ]
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9 }' A7 }1 A! @; ? reset-ticks+ I9 F! g" z* F
end
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;; Initialize the global variables to appropriate values1 u3 `: ]0 `3 Q
to setup-globals
& h, I4 U2 G& F' t4 f# [9 c5 ^ set current-light nobody ;; just for now, since there are no lights yet! U% _1 G# U, E, H# B$ _7 n
set phase 0" p8 ^. T- T2 ]+ C
set num-cars-stopped 0
; W# K4 ~) F9 O6 k$ K- [& e set grid-x-inc world-width / grid-size-x
1 ]+ L4 k% X# d: A7 U6 C4 m set grid-y-inc world-height / grid-size-y/ l3 a" i" G2 w5 D8 t8 b0 ]
* ^8 Z* I6 z, Y ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
' C4 @4 u! s2 t& B+ T( \# U0 x2 f set acceleration 0.099: \0 Y9 q a2 G$ a2 T9 a
end
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$ B" V4 N0 Q% S/ a0 P! O) E;; Make the patches have appropriate colors, set up the roads and intersections agentsets,. L* o; B# z" z( f0 z3 A7 Y
;; and initialize the traffic lights to one setting- f1 @' l, z1 S! _0 m, _
to setup-patches8 J9 R0 s& L; F8 }- C8 x% n" E& i/ e
;; initialize the patch-owned variables and color the patches to a base-color
' Q% j( W! B( y+ o H$ E# P. ] ask patches" j" c% [( v# S; U3 L5 r( F; k2 t
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set intersection? false! G" F3 l/ b' |/ K5 }
set auto? false0 X/ B: ?7 x% w% E% T+ ?+ U9 y
set green-light-up? true5 _7 K* m. F9 [) o3 i
set my-row -1# p% {' G; G+ Z1 T2 X$ |
set my-column -1. I. E' T" j; k. g* P: [+ S/ l& O1 m/ l5 K1 E
set my-phase -1
& k* y) `8 l+ M2 G* C! f2 p set pcolor brown + 3$ p, s) L8 S& |5 R' h( `! O) N
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;; initialize the global variables that hold patch agentsets
, X r! U ]7 m/ e1 Z3 i" Q P set roads patches with
2 h1 G6 q% ^$ a2 h# a: | [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# s, j2 h: x' p (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* M& ^+ H8 ?" ]; K set intersections roads with2 H/ ]( S8 i) k G
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
, D% ^8 F/ [1 _ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]9 p3 p- ], M: T) Q
setup-intersections; [; F7 F. F! L+ v3 ]: p: w
end; ^' E, M$ e! n
其中定义道路的句子,如下所示,是什么意思啊?5 |( L6 ?0 ]4 M% O1 ~* k
set roads patches with# `. B4 X8 ?! ?& }" [
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or& m$ @2 C7 J5 Z( D- t- M% |
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]) \( Z p& q l( T1 j; {
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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