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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。' G6 x8 o! H: Q! ^) u
netlogo自带的social science--traffic grid这一例子当中,: Z' _( j; ?6 o" ^" |3 d! W- U
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
" @/ w, W% _1 p, C grid-y-inc ;; the amount of patches in between two roads in the y direction& u! D" e. Y9 ^0 s4 L$ f
acceleration ;; the constant that controls how much a car speeds up or slows down by if O8 \7 r# Q2 _( c& C& k
;; it is to accelerate or decelerate" e1 c) g3 G. Q1 r
phase ;; keeps track of the phase, o' p3 U7 b- U3 B( Z$ A
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
: I, s: R" T: X$ u current-light ;; the currently selected light
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- F! D$ U8 j! u! c6 E: G6 E+ o+ p ;; patch agentsets
7 B8 I/ Q# _+ l }1 _- Z intersections ;; agentset containing the patches that are intersections
0 n# ]/ w/ a- V& I roads ;; agentset containing the patches that are roads
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1 g+ h6 \2 {6 cturtles-own
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) J c1 x% P( ]8 y i speed ;; the speed of the turtle; |3 ^( o: j3 D7 }! a
up-car? ;; true if the turtle moves downwards and false if it moves to the right1 y D8 `4 b# Q) k! H0 `
wait-time ;; the amount of time since the last time a turtle has moved. e2 j% j5 N: C+ j: ]/ U
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patches-own
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9 Y8 N/ H* a1 o& C intersection? ;; true if the patch is at the intersection of two roads
6 |2 d, K8 {* m9 G' ] green-light-up? ;; true if the green light is above the intersection. otherwise, false.: q& J" }+ }5 s( j. ~ q' p0 M
;; false for a non-intersection patches.1 L7 x: v3 j9 `, m
my-row ;; the row of the intersection counting from the upper left corner of the
' I' B# |8 B+ `+ D" F8 e/ r ;; world. -1 for non-intersection patches.) _5 L& e' K% h
my-column ;; the column of the intersection counting from the upper left corner of the
4 | d7 }; o# `7 i( g, D ;; world. -1 for non-intersection patches.
. R3 a" q( G; k, R my-phase ;; the phase for the intersection. -1 for non-intersection patches.
: G1 Y& f3 [3 i. `# J! e auto? ;; whether or not this intersection will switch automatically.6 v1 C3 T6 Z( W# o: |
;; false for non-intersection patches.
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5 |1 X0 g- s1 f- I( P& W+ o;;;;;;;;;;;;;;;;;;;;;;+ K/ T9 v: {& c) m* `
;; Setup Procedures ;;# I" d# N( y# Z2 ]7 ]
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
5 ]- l* d1 R% R9 W& p/ O* R4 P5 };; Create num-cars of turtles if there are enough road patches for one turtle to
5 P8 W" O; o8 P6 u;; be created per road patch. Set up the plots.
; U1 ]" f5 ~0 ]: q% zto setup
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0 c- M( C. { N9 r2 K6 y setup-globals: u3 a7 Q, J4 o# z$ G; v3 P
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;; First we ask the patches to draw themselves and set up a few variables' t0 }; N. {6 T1 @# J# Q) [! o
setup-patches
9 R! A N, w+ l( W0 j4 C make-current one-of intersections! c+ x) S* Z+ z7 D' G& t2 e
label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "$ U' ]. Z2 P2 y& a7 W7 ?" o
"road. Either increase the amount of roads "
. P6 Z$ K! w. G& H$ S "by increasing the GRID-SIZE-X or "' P8 L" R% g$ v
"GRID-SIZE-Y sliders, or decrease the "7 l6 h3 q9 C; ~: h
"number of cars by lowering the NUMBER slider.\n"
5 O/ r$ q f. Q5 I "The setup has stopped."); n& P$ I% V$ n v. _
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color7 i% w- p( I+ A8 z
crt num-cars+ c0 K4 @$ ?; e
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$ G- D$ Y1 k3 E- l# N/ P: m% } setup-cars- F/ ~2 H1 Z1 c! Z" E
set-car-color
( J* S+ D+ V" X7 J record-data
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0 z/ m3 D0 g" |, b ;; give the turtles an initial speed
' U1 C, B& g }; Y: W# F ask turtles [ set-car-speed ]) d& c+ A, x% e; {, ~
) g7 [( ~! ?) h' F0 z7 v reset-ticks: D/ l5 b5 n `. Z4 C
end: C/ O( i3 _% }6 q5 ~
6 J! `# ?8 D3 ]7 c' w- g;; Initialize the global variables to appropriate values- M2 r+ b2 }/ _. u& B
to setup-globals
6 ~- q% t" @ x4 z+ P set current-light nobody ;; just for now, since there are no lights yet
" A+ ~' M& L, k% u F' q. `# r set phase 0
0 Y7 r; ~* R1 V3 }% y* w6 G set num-cars-stopped 0 z, s' K5 n* _ e* v
set grid-x-inc world-width / grid-size-x
" \9 K! Z7 s2 \/ J set grid-y-inc world-height / grid-size-y
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+ o. a9 q6 X- F+ @% W4 p3 y ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
. m9 k( S6 d8 G9 `1 ?& m set acceleration 0.099
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8 \0 B9 {* ~7 [6 K* |;; Make the patches have appropriate colors, set up the roads and intersections agentsets,# X9 u- T/ W, J: _8 }
;; and initialize the traffic lights to one setting
# k4 x* _% T* C* oto setup-patches
' W# o [5 m" X# Z7 b ;; initialize the patch-owned variables and color the patches to a base-color
$ E; U! k# M! v. X ask patches3 z/ x& O i8 F7 T# [
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set intersection? false- j _, a2 U9 a
set auto? false
& t+ ]# T" l R. [ set green-light-up? true2 U: V- M" X8 j0 q k# b, z8 U
set my-row -1
& v- D; ?0 V! {( a# J set my-column -1$ C# H' g! u9 I( U) C' X# Y$ H
set my-phase -1
0 b$ I& V% e3 k" v4 C; \ set pcolor brown + 38 B: y P& W5 n3 z
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;; initialize the global variables that hold patch agentsets" E# y \0 \5 \7 q, L
set roads patches with; [+ Y& ? ]+ p
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% f# w! u6 s* A/ z; r
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]! P0 q0 {0 b6 k3 I% t
set intersections roads with" j) C/ T1 t' F: @! c" C. g
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
/ w3 U" ^( N$ B/ [* U (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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% S+ C. j% X. S" I ask roads [ set pcolor white ]4 Z2 @+ i; v8 J+ J) [" |- B. g
setup-intersections
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0 S9 U: c- f$ N& {: d. [2 ~: Q3 ~1 I其中定义道路的句子,如下所示,是什么意思啊?9 i6 [' r N5 v N
set roads patches with* A9 L7 T+ j3 i+ d
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# t5 @; j. ]/ A, d- { (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ ?1 m/ w: s0 c' Y, R \& n4 k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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