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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。! ~7 a3 [5 |/ r0 v, x, b q- f
netlogo自带的social science--traffic grid这一例子当中,7 X5 I- R& n$ `7 s9 z& Y
globals+ T8 W0 J% A0 Z. z% D9 F6 u, \
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grid-x-inc ;; the amount of patches in between two roads in the x direction4 p( p" K! T0 i" U- R. k
grid-y-inc ;; the amount of patches in between two roads in the y direction+ U* t' ]: e: m; i" C
acceleration ;; the constant that controls how much a car speeds up or slows down by if( O( t6 }# o6 [' S
;; it is to accelerate or decelerate
' A! f! E) y, C! | phase ;; keeps track of the phase
0 g+ {% ^4 b8 V num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
3 q6 Z; w* t, q+ X+ v2 x current-light ;; the currently selected light
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;; patch agentsets
1 |% ^7 z0 M7 R- M( ~& U& X intersections ;; agentset containing the patches that are intersections
, }% a, B1 ^8 p roads ;; agentset containing the patches that are roads
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turtles-own( d. @! p% X9 n6 h8 E
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speed ;; the speed of the turtle
5 ]1 v2 H+ r7 [7 P$ O up-car? ;; true if the turtle moves downwards and false if it moves to the right: m6 F+ Q5 b$ m3 }
wait-time ;; the amount of time since the last time a turtle has moved1 A8 S Z l" ], p- k# O2 y3 b
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2 Z5 v1 B0 l! [( @! t3 b \9 A( O. Cpatches-own* G) d6 A* ?3 z2 _1 S' s
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intersection? ;; true if the patch is at the intersection of two roads0 O* q- U3 [! m& p) \
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
8 \1 Z& X }0 o ;; false for a non-intersection patches.
' r2 o6 h4 e" x4 O1 W: _ my-row ;; the row of the intersection counting from the upper left corner of the6 ^( p, g. [+ N$ ~8 f) ~
;; world. -1 for non-intersection patches.
( v6 K9 W5 E; U my-column ;; the column of the intersection counting from the upper left corner of the
m4 o; F! d0 \- |, Z ;; world. -1 for non-intersection patches.
" u, Z$ T2 ]% E. g, u- {& F my-phase ;; the phase for the intersection. -1 for non-intersection patches.
9 _" A; p. b$ [+ S1 I" O) x$ { auto? ;; whether or not this intersection will switch automatically.+ b! _4 F0 E4 X- F
;; false for non-intersection patches.- T" s+ `7 D/ N4 m1 a$ G
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: U4 v0 C5 I2 F5 B% R) s;;;;;;;;;;;;;;;;;;;;;;
1 _: G* M: }* H, |2 ~" q;; Setup Procedures ;;
; w1 M: |( U. ^$ @. k+ ]. Q;;;;;;;;;;;;;;;;;;;;;;
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1 ~9 I( c7 K2 N. m; H; J5 y M) k g;; Initialize the display by giving the global and patch variables initial values.
V, T+ T* Z/ k8 M$ U. ];; Create num-cars of turtles if there are enough road patches for one turtle to
, ?, O. D1 P1 V1 y& G; I' c;; be created per road patch. Set up the plots.! ]3 P! n6 x: F! v B ]; Z
to setup& m; c5 Z! D8 F: A$ ~
ca
6 N, n; U5 F, y0 Y; k setup-globals
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;; First we ask the patches to draw themselves and set up a few variables1 f. ^' K' Q, k5 X# O8 j1 c! l, w4 @
setup-patches
# P2 m0 R" W/ q0 \( O make-current one-of intersections
& k6 T0 s) K( K. U, d6 |: L2 p label-current
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1 m, K7 \: I, f1 |- E set-default-shape turtles "car"
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if (num-cars > count roads), _. ~) a J/ ?" ]+ v2 J' P
[
3 Y* G( E) t' v4 U8 Z$ h user-message (word "There are too many cars for the amount of "% P3 |- o4 [# s
"road. Either increase the amount of roads "; s2 ?0 Y$ E9 o9 x9 C9 n/ n
"by increasing the GRID-SIZE-X or "
& D* Z- A4 {4 T4 N1 m! c# T1 }; [ "GRID-SIZE-Y sliders, or decrease the "
" H$ g& N9 r; Y* {* q6 Y% L- [) d "number of cars by lowering the NUMBER slider.\n"
8 S# d8 I0 D4 C7 } "The setup has stopped."); d) i1 @2 A* h3 Q g! k8 R
stop* ] n }6 @$ A2 i1 x
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color* ]% N) h% j4 ?. I
crt num-cars
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: A3 U& ?7 f( E: j/ G setup-cars) c! U1 J& c) t V6 m* R
set-car-color
' R) R; ~* y1 `' d record-data
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! q4 D6 z$ U0 |! E# J6 f ;; give the turtles an initial speed2 n I* r& H" U+ p# u8 [) w* t) e. g
ask turtles [ set-car-speed ]
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reset-ticks' i6 p/ X4 m# A- s/ M! @
end
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;; Initialize the global variables to appropriate values) u5 L: U) s, t7 d, F- N
to setup-globals! p+ `" F6 B( t d8 i! b: v$ c" j9 g+ N
set current-light nobody ;; just for now, since there are no lights yet( g. Q$ o: B! k- t( U0 n
set phase 01 B! `/ r7 j, N: n1 k
set num-cars-stopped 0% [" y3 q4 Q% C6 d7 j* S( v& f
set grid-x-inc world-width / grid-size-x8 Q& T/ T8 K/ ]2 r- Z( o# \. D9 y4 U
set grid-y-inc world-height / grid-size-y
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; o& v. ?' i* Q z* e0 Y ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary) X4 [4 L3 N4 @- h8 i7 G
set acceleration 0.099' N, x* C# ~" F
end9 {) L1 Z% {9 X) A+ W8 v
4 T, i/ n( s4 r( e;; Make the patches have appropriate colors, set up the roads and intersections agentsets,2 b" b' Y! l" y, `1 r
;; and initialize the traffic lights to one setting& N& o1 \! i8 e0 R
to setup-patches
& ]! { t7 x [0 s ;; initialize the patch-owned variables and color the patches to a base-color3 s: B' a- S1 P" E3 R
ask patches
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) Q8 Z1 Z8 r/ f& N4 p' { set intersection? false
$ m1 M. ?8 q; h! A& O% s set auto? false3 f5 \$ P# o' Z. R% X3 y/ v* m
set green-light-up? true
: {- \# r$ h! \ set my-row -1, H% b1 v m7 u( d! c
set my-column -1
1 u) T$ R6 H5 `( S- G set my-phase -1
% E; u" P9 X8 V- j. U, F n4 `. i set pcolor brown + 3( G9 k9 N5 u/ Q. c( l/ g
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;; initialize the global variables that hold patch agentsets
+ w1 S8 i7 f' R( F set roads patches with
+ q2 b& n- Z7 M3 V [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or- b6 [; U4 {- l/ k3 s
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, H! d$ C- `5 U' j, ` set intersections roads with) q- \+ `1 |' }# m- E5 s9 e& {5 z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and( |) H$ L' V. B6 o
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
% U3 @7 H" x; p7 Y6 u setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?
& f) V6 [+ w1 X" o set roads patches with# z n: z) r- u' H. b& }( E: D
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" s0 Q- ~! F6 |9 e6 E$ o (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) `; p. z0 a$ q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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