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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。 O1 A: \0 Z0 u! y6 Q/ ^
netlogo自带的social science--traffic grid这一例子当中,
% U1 [4 h8 h/ K# X/ b! Xglobals
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0 @! j% k. s4 H2 C% r! C grid-x-inc ;; the amount of patches in between two roads in the x direction
" i5 h! A( F. P. L9 W* T grid-y-inc ;; the amount of patches in between two roads in the y direction& I: X/ ?3 Z' R( U2 V9 @3 F8 q
acceleration ;; the constant that controls how much a car speeds up or slows down by if% q! ?9 C5 u+ M
;; it is to accelerate or decelerate* I2 z- _. [: S* J3 K" S; B H- t
phase ;; keeps track of the phase- z! B" R3 }, X7 g( z* ?0 l7 ]4 n
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure: V" G8 n. I& ?" M
current-light ;; the currently selected light
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;; patch agentsets. X* P& K' h: q; d, j4 x4 A
intersections ;; agentset containing the patches that are intersections
$ F' z8 Z) ~6 B6 y roads ;; agentset containing the patches that are roads9 F/ i4 C# j* |+ I1 g, C
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! T7 q0 Z9 W9 I( Zturtles-own) ]8 [: w9 m; m$ L5 I2 N1 N; ^; x$ i
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speed ;; the speed of the turtle/ ?4 e: d4 K4 f3 u4 o
up-car? ;; true if the turtle moves downwards and false if it moves to the right
! a/ t* D# f/ K' n wait-time ;; the amount of time since the last time a turtle has moved
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1 ?9 W/ Q3 P f/ [1 h8 Lpatches-own
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intersection? ;; true if the patch is at the intersection of two roads" ~( |5 `" i3 R- m: L0 x
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
8 q0 d* l$ f) ~; u ;; false for a non-intersection patches.
2 ?. O6 ]& ?7 p1 [* N my-row ;; the row of the intersection counting from the upper left corner of the7 J, s0 m8 ]+ {& {7 p& k+ Q
;; world. -1 for non-intersection patches.
/ B( C1 b4 ]" v3 v2 V my-column ;; the column of the intersection counting from the upper left corner of the5 H1 _2 {+ X. n) {+ ~
;; world. -1 for non-intersection patches.8 a0 l) E. p0 B5 j1 h6 F# i0 Z& F
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
! J7 q1 s; m6 h auto? ;; whether or not this intersection will switch automatically.
5 D" `, Z4 O2 a, | c) T" P ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
( D' P! }! ~6 i2 M- q0 G. D D;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
/ W$ ^4 I& l4 y;; Create num-cars of turtles if there are enough road patches for one turtle to% z+ S- {+ T9 [" [+ x( `
;; be created per road patch. Set up the plots.
+ ?8 y( A# M) n5 @/ j9 j: {1 dto setup7 G+ a! M0 F4 h' ^, _
ca
4 M. q* D; }0 x2 j- f' t2 l! ~ setup-globals
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9 }, b% w9 Z" G- ~* f ;; First we ask the patches to draw themselves and set up a few variables" C# S3 r1 w' _& e& d
setup-patches) F, S6 Z$ P3 o
make-current one-of intersections/ J, g* o" d; ]( n# L
label-current
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! l, y) N. s" N% h ` set-default-shape turtles "car"" L `3 @6 a9 [4 x% D7 |$ q' Q H$ \
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if (num-cars > count roads)% d w2 J. ^- d4 a5 ? d0 {
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8 p3 {! Z0 k: v5 b, \9 ^ user-message (word "There are too many cars for the amount of "
$ Z! C1 K4 B( i% Z5 c "road. Either increase the amount of roads "
* ]. Y; U1 t( t4 u. k "by increasing the GRID-SIZE-X or "
; E/ |$ r: }' A, T6 h "GRID-SIZE-Y sliders, or decrease the "! J0 g6 K) n% v( z* g
"number of cars by lowering the NUMBER slider.\n"
* _5 V. F% [0 s9 l "The setup has stopped.")
/ n# Q' G5 u$ `4 j! x9 g, C stop$ |% c( X# \6 H$ {! k8 ~
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0 _5 O/ _9 j, Q8 |9 B ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
1 F: c" s/ R) n; |# F8 l1 \% A crt num-cars6 E! l! t- K9 p* H$ f
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setup-cars l7 _! m0 W0 N" H
set-car-color
F6 y7 S, \ \8 o; z record-data4 _, L7 d. C$ B* M
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;; give the turtles an initial speed
; K1 u# m9 m9 r6 o% k ask turtles [ set-car-speed ]' A. i7 L; n i6 h
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reset-ticks
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;; Initialize the global variables to appropriate values
: p, w; {( f# W Z. Z8 b6 z" \' vto setup-globals
# G0 P; ]$ U, } A) m5 { set current-light nobody ;; just for now, since there are no lights yet
; U; _% M3 ` w7 B0 E9 b# n set phase 04 P5 y. t8 Q& p) E2 o
set num-cars-stopped 0
. ^. F! D9 W |2 u: |: T# k9 ~ set grid-x-inc world-width / grid-size-x
/ p. t% \. ~ P4 m set grid-y-inc world-height / grid-size-y
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& m! R1 [# t1 D' \ ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary/ z1 ]+ P& |) H- ?6 `5 C3 b
set acceleration 0.099, ~2 G9 ^) [7 n& q! M
end! Z0 Q9 q* e) T
1 A, d( r4 \8 V; G! b0 p;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
, b$ F1 ]* V: w: {# ?; f) w;; and initialize the traffic lights to one setting9 |0 q: ^( p/ K5 R4 J: d
to setup-patches
" ]" r( r- y7 c$ v2 H& G8 P. k ;; initialize the patch-owned variables and color the patches to a base-color( C9 ? z( V( C9 F
ask patches
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/ Q2 F+ I* E, y [; T9 R" b9 G' ]( ^( N set intersection? false- w$ ?( y9 d2 p' D* A. d
set auto? false
6 {! x% R1 Q( r' b/ V! }% S( K set green-light-up? true F5 v& j: j( v* x/ u& @# H7 B
set my-row -1
' e/ L* O$ R, D h. ^: l0 Z set my-column -1/ [ ]3 v; x+ R# a$ A- A
set my-phase -1: t, _! N2 \/ _, E. H2 z7 H
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets8 N9 E# K1 Q0 |2 [4 `$ n* K
set roads patches with" B9 z4 _7 W- |8 Z- u
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
3 K2 q" ~, l5 r) i7 p- _5 s (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% \# k! s2 G& w/ b9 O1 B/ k& A set intersections roads with/ J: ~ X9 X. O+ Y3 K) e
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
R, R1 J, f% @# t' e (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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end+ n1 t9 k$ D- s, v) w
其中定义道路的句子,如下所示,是什么意思啊?: L# q- Z' y# C- Q: U: J
set roads patches with
/ O6 e: r _9 \7 _ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
. Q, N2 B! q8 p$ Z' B9 l (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" E% ?: r3 [- ]" ^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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