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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。3 h, q2 } i" W' c% n( W% T
netlogo自带的social science--traffic grid这一例子当中,
e5 E- Z9 d2 T! r% ~globals
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9 B2 Y [! L& u+ t grid-x-inc ;; the amount of patches in between two roads in the x direction6 V* e5 `* C. W( m
grid-y-inc ;; the amount of patches in between two roads in the y direction
" y" K" Q! I$ J: m8 ^( W6 q acceleration ;; the constant that controls how much a car speeds up or slows down by if
) p0 }/ T- `- y% H$ v+ O ;; it is to accelerate or decelerate
9 t! _/ E% c D3 j& V phase ;; keeps track of the phase
C' S" B$ q& [2 m1 u num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
3 L% Q1 w+ n1 y& d1 ~' K current-light ;; the currently selected light
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) {& l1 g [' H: l- p ;; patch agentsets/ S6 s# O5 r! k' w1 Y. _4 |
intersections ;; agentset containing the patches that are intersections6 y- X/ P; a) W& v9 V
roads ;; agentset containing the patches that are roads
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' R* A5 G. k: n. \ @: [turtles-own" m! A6 J8 ^( x0 q8 P9 ^1 v
[
) Z, x. z! k3 U- I& U8 K speed ;; the speed of the turtle
, q: ]0 r2 @- E \+ L+ W" T up-car? ;; true if the turtle moves downwards and false if it moves to the right
1 @% g% s; N! a1 U wait-time ;; the amount of time since the last time a turtle has moved" }: B2 a, M/ ^+ v
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
2 {3 H" c; s' Y6 g+ R q* K green-light-up? ;; true if the green light is above the intersection. otherwise, false.
& ~) o6 b2 M* O& X) w ;; false for a non-intersection patches.
, t: s1 L3 m3 U7 L- T% o& ^ my-row ;; the row of the intersection counting from the upper left corner of the
( W5 s/ c) D" Z- X ;; world. -1 for non-intersection patches.. c" O/ x" U( H9 q/ }
my-column ;; the column of the intersection counting from the upper left corner of the
- W: t6 F2 t3 U ;; world. -1 for non-intersection patches.1 C/ Y; E$ H& P6 G7 J: o1 i. C% I
my-phase ;; the phase for the intersection. -1 for non-intersection patches.) P! a# f. W- M+ G& x
auto? ;; whether or not this intersection will switch automatically.# R) A( H5 V4 w% ^8 j
;; false for non-intersection patches.5 c: A& b4 g( \' `3 M
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;;;;;;;;;;;;;;;;;;;;;;, X: c; G1 [) m& t
;; Setup Procedures ;;
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$ }* M: W {& ~& o;; Initialize the display by giving the global and patch variables initial values.3 [, t3 Y8 ~# T5 M/ a2 r
;; Create num-cars of turtles if there are enough road patches for one turtle to
/ r* e2 X8 u$ X) _- P/ y;; be created per road patch. Set up the plots.
2 D) D9 _0 k: i3 h& _* Y6 Vto setup/ _/ d+ k5 W& R$ z( v1 b9 `% ]
ca
, u. {/ C7 T. D! w setup-globals
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;; First we ask the patches to draw themselves and set up a few variables) {, k' E2 K1 K0 u2 t2 H8 W! n
setup-patches1 P R& g7 P' S' F
make-current one-of intersections
- I3 W- k1 x8 [+ Q label-current1 U% s& `: L! o4 b% a5 K
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set-default-shape turtles "car"
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/ L3 w/ J9 x" C7 t if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
. f2 g- u' d1 I* Y7 L "road. Either increase the amount of roads ") D( h) T# l( k: g1 `
"by increasing the GRID-SIZE-X or "
$ O' n* K! p, o3 t, |5 S$ l& [/ a "GRID-SIZE-Y sliders, or decrease the "
2 ?& G& g3 _, ?9 x+ d0 X; F "number of cars by lowering the NUMBER slider.\n"
) q! j! f. p# C: U "The setup has stopped.")
3 \ W; v& Z2 j3 K' G8 F stop- f! y8 O# a/ h l& e2 u
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, y$ J* w" S( ^# m ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color0 M( e/ m6 \% m; `$ W
crt num-cars2 `( v4 _7 T0 b% {1 q7 L1 L
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5 C* u2 B& Y3 x9 E' M setup-cars% L0 I7 t4 A! k$ u8 z
set-car-color6 A# G7 _0 K' w) ~
record-data2 N2 Q* }; j0 }1 U6 H
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3 g7 ?% q4 y; ]2 I# h! W ;; give the turtles an initial speed
7 O( s* Y- {5 m h% l! m8 B# h ask turtles [ set-car-speed ]! u5 Y( c7 \( m. C
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reset-ticks; h: E9 d0 J) Y( R
end7 @' M1 S, n6 i$ {; d5 o
+ e) M) J. _# P- G1 @. e- @;; Initialize the global variables to appropriate values1 g0 F/ \- z! v- h
to setup-globals! F5 q1 W. ^- ~) v" q: S
set current-light nobody ;; just for now, since there are no lights yet' T2 @6 B+ H9 v! r) ^# N* f# j8 P
set phase 0
7 g9 Z( W3 \9 u, D5 w set num-cars-stopped 04 i3 c/ Y9 |" T: H
set grid-x-inc world-width / grid-size-x7 f3 v0 N! F) R- | P- M$ w
set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary- p3 d7 O2 D! n4 B% D$ v+ T& L
set acceleration 0.099
, }' f. M2 ?) p) cend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets, a/ s* j' F: q% Q4 j& B% Q( G* U" Y
;; and initialize the traffic lights to one setting
9 S \: |1 n" d5 Tto setup-patches
2 q q1 t `7 ~3 p/ f' \ ;; initialize the patch-owned variables and color the patches to a base-color
1 u" Y! k- e5 s. ^% A ask patches
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! M, r7 Q3 C3 T. u# b8 s set intersection? false9 O2 H' J% ]- I* S4 M6 G8 p
set auto? false* T3 `/ L1 @# j" I
set green-light-up? true4 s# r' M5 z# E# S
set my-row -1
. o/ [! V- ]' S/ `3 C* ^6 ` set my-column -1, L0 G9 g$ H8 }" Q1 S" l: R$ g% D
set my-phase -1
; O3 s' x4 C0 v+ I3 c7 R set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
4 G6 i* H$ y- d) y! n; d set roads patches with0 ]5 X* V' I9 H" t
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 o* @" W @+ f0 H/ B (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 y' P( l" W, g- a9 \ set intersections roads with
9 e' M" e, j8 } [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
# c/ J# O+ g/ {! G L+ i (floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ A8 @$ s' w* v6 y; p5 p' v7 c
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ask roads [ set pcolor white ]
& k0 b+ ^4 Y# |- V. H3 {: v setup-intersections( ?7 w$ |5 q5 V6 K
end2 L0 a5 M5 H8 c. q4 ~/ U' L2 u
其中定义道路的句子,如下所示,是什么意思啊?2 Q' K5 ^: H. |6 l
set roads patches with' G0 L P1 U( q5 w9 T, ]1 Y, U/ q' V
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 l, g+ c# `* p+ \4 M8 B2 T$ }- D
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 t6 `0 t3 m" c8 [% t
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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