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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。* P2 d; z# r- ]" z& Q
netlogo自带的social science--traffic grid这一例子当中,
' z! P2 \0 ]% I' H6 b. tglobals
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+ ~2 O! X3 ~/ j" }6 u1 b grid-x-inc ;; the amount of patches in between two roads in the x direction
+ c2 @2 U# |4 g" e, c g grid-y-inc ;; the amount of patches in between two roads in the y direction: k& L1 }) [5 W% y6 H. f
acceleration ;; the constant that controls how much a car speeds up or slows down by if
/ _1 l2 U$ s4 C2 m ;; it is to accelerate or decelerate" v2 s+ g, }: i& B% Y4 P5 {' e- a) A
phase ;; keeps track of the phase! O5 I4 s z& c
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure9 U, G$ Z+ A, `- H& O9 t5 i' X
current-light ;; the currently selected light
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( x5 F" v1 `, M9 I3 _ ;; patch agentsets
+ A9 S, f" k0 U" D0 c5 m intersections ;; agentset containing the patches that are intersections* P8 v) c6 A5 T0 z6 N
roads ;; agentset containing the patches that are roads) m. N' B' k) e3 M( A2 }) V
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% c! Y% }$ I9 y5 iturtles-own* ^/ Y8 a$ h- ~
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speed ;; the speed of the turtle% B' d! i v3 e' q7 v
up-car? ;; true if the turtle moves downwards and false if it moves to the right
# p; J+ j7 g- k" X2 f) X+ q& E wait-time ;; the amount of time since the last time a turtle has moved4 S# ^. q! _, Y, v$ L3 X! z5 P) k! k
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& u2 H, ^- K' V* ^# P) p! vpatches-own/ @2 F' E! [# h/ f/ q7 Z, G
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intersection? ;; true if the patch is at the intersection of two roads* `% i9 k1 h; e4 O* u: J7 c
green-light-up? ;; true if the green light is above the intersection. otherwise, false.$ V( W/ ^9 A# |+ n
;; false for a non-intersection patches.+ W8 c2 T5 D$ d7 c4 y# I
my-row ;; the row of the intersection counting from the upper left corner of the
7 X$ \2 M7 \1 m) G% U$ w4 M% \) M: \/ j" w ;; world. -1 for non-intersection patches.3 h& N# {1 O4 H* z+ n* c. S
my-column ;; the column of the intersection counting from the upper left corner of the
0 q$ Y, Z) m5 c ;; world. -1 for non-intersection patches.
2 @- G0 P1 T- H: \ my-phase ;; the phase for the intersection. -1 for non-intersection patches.
, u' Q- u7 ~ Y7 w0 u* C auto? ;; whether or not this intersection will switch automatically.
7 |0 x/ G1 [& {, z' o ;; false for non-intersection patches.
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" x0 E3 M5 X2 m5 p! K _- t2 W;;;;;;;;;;;;;;;;;;;;;;
- G" J } w6 W9 b;; Setup Procedures ;;
1 o) N- A5 } A$ e! n;;;;;;;;;;;;;;;;;;;;;;+ J# g1 ~& I. O0 N% P8 G! I1 w
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;; Initialize the display by giving the global and patch variables initial values.5 q$ Y0 P* ]& X: E" J
;; Create num-cars of turtles if there are enough road patches for one turtle to
" o& L% Q. P, |3 O;; be created per road patch. Set up the plots.6 M; l9 X- n: Y) N4 D
to setup
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# K; k4 K# t+ B9 e) E- m2 L setup-globals
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;; First we ask the patches to draw themselves and set up a few variables9 Z2 v9 h9 V) q. z3 C" d
setup-patches
) m' Y# N' b& F make-current one-of intersections0 M" ^$ N/ i+ P6 ^9 Z6 E1 G
label-current8 {% e3 Q% f, M# M7 h: k
7 ^: ^* ~3 A& N set-default-shape turtles "car"
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if (num-cars > count roads)6 h8 l% A& M) v- G" x* y
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7 m) g# `( H3 ~ user-message (word "There are too many cars for the amount of "0 C, {% R! U: n, B2 v
"road. Either increase the amount of roads "
) x6 E0 d8 o9 K) N: U "by increasing the GRID-SIZE-X or "- V% X1 F" @. e4 T+ @( D# \
"GRID-SIZE-Y sliders, or decrease the "
. ? c% E9 i( e6 h: K6 T# o8 i "number of cars by lowering the NUMBER slider.\n"
+ J1 [+ n9 M W2 `9 X2 \" w7 E "The setup has stopped.")
2 S2 j& W# P& b$ n stop0 o0 @5 j$ X, t1 I
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2 P9 W7 X$ Y2 S6 u$ B& \ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color- g7 {, a7 O2 D7 y R# D
crt num-cars+ ?- A6 ^* j( w$ z" l: ~
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: c* x1 Z3 j- F2 e0 c0 S6 T setup-cars7 k, ]# B/ X" Y- m* O" M' W* Z `% u/ I
set-car-color; r+ j' \: w9 q5 P! F
record-data4 ?* B' h/ }# x5 d) l
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;; give the turtles an initial speed. U) P8 E6 W, f# {5 C" V3 r1 b
ask turtles [ set-car-speed ]
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reset-ticks4 N) @# B) z( R* K0 @
end
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6 {4 w* @( r9 P7 b# [% @# o;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
. c: P% h" G2 y$ a set phase 04 O) s k& w8 g5 U
set num-cars-stopped 0& }' N2 q+ y! m
set grid-x-inc world-width / grid-size-x) e' _7 @. u7 F7 F" {# A
set grid-y-inc world-height / grid-size-y4 v6 a. M7 ]- ~5 p8 B3 U
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary0 R# {1 R2 D6 O
set acceleration 0.0998 k# }; C v2 n9 b2 S, ?2 ]) u
end1 h% V' m4 T/ E; \$ U) z4 i7 ?
2 Y x! g. g. l4 ~) F+ p# J;; Make the patches have appropriate colors, set up the roads and intersections agentsets,( I7 U2 i, q! [7 `/ e/ e# F
;; and initialize the traffic lights to one setting/ I" u7 S% F. C: Q& J* G! R
to setup-patches
0 N" s, s/ h: I4 D- b% m ;; initialize the patch-owned variables and color the patches to a base-color
9 R5 u* _0 h0 N. }4 _4 A0 r ask patches f0 N3 i* B/ h
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) |, I* B( M: D set intersection? false
+ C! [" z1 w5 u$ G3 h set auto? false
5 v; I7 x+ q# n% v1 \2 j& K: S set green-light-up? true
a! k3 a0 k% h6 E set my-row -1- ^7 l( J& W1 W, O/ y" F8 O
set my-column -1$ | V3 ^6 b* h, X( e9 b3 W
set my-phase -1
; M+ P2 q$ X9 t2 e- ~6 Z6 l/ K set pcolor brown + 3* j8 H" \$ C9 d9 [# H9 q0 ^! a( i
]
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) y& P% ~ S( m! V0 W* n ;; initialize the global variables that hold patch agentsets
( d/ F& z1 W2 I& L1 R set roads patches with$ B, ~8 s" R3 R; V, j
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
, c7 \& r, m1 X! N( O1 R; G (floor((pycor + max-pycor) mod grid-y-inc) = 0)]' ^* r6 U, t6 D" |; u+ s* w1 k4 B
set intersections roads with* M. @, D- _8 ~8 E( f/ p5 y7 w
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
B+ r1 }$ h5 g% N3 A( z$ W (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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( m+ V3 ~7 T6 ]* g ask roads [ set pcolor white ]7 \0 F% r6 M7 ?: v" g1 n
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?
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[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
- m: G# @5 Y) a. j: U! r (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 p8 L% K1 Y- }' W4 }3 d. [1 ~0 O& x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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