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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。: F; v# t4 w2 ^! a
netlogo自带的social science--traffic grid这一例子当中,
2 E8 H+ l+ j0 n6 Lglobals; N. L+ Z5 x q' J/ D$ R
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! v9 K7 K& ~# ~' x5 l grid-x-inc ;; the amount of patches in between two roads in the x direction
9 i/ x2 m( Z) [2 i7 h+ B' L+ ` grid-y-inc ;; the amount of patches in between two roads in the y direction
. s! B, s% B* U1 A0 y acceleration ;; the constant that controls how much a car speeds up or slows down by if% g1 N0 y2 q% i3 t; M9 Q) g
;; it is to accelerate or decelerate; r5 I' e: o# o$ U: @
phase ;; keeps track of the phase
3 {! [' c' I X- L1 F% o' H$ D7 L num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure' }! d, V! k9 ~) ]6 g6 P, i1 e7 e! ~3 L
current-light ;; the currently selected light
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;; patch agentsets
& D6 o J* H/ k" H- @- \ intersections ;; agentset containing the patches that are intersections
& u: Z! Q j' `6 F! F { roads ;; agentset containing the patches that are roads% d" b9 ^, s" E
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* e8 f& ~1 M3 w' Bturtles-own6 ]! Q) s" o0 @
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speed ;; the speed of the turtle% a- z* Z, t& r9 | U4 ^+ z4 u* x9 Z
up-car? ;; true if the turtle moves downwards and false if it moves to the right# j! h) i$ v0 ^& u& g( ?
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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3 m1 q& Z" Z( m& N. \' E9 h intersection? ;; true if the patch is at the intersection of two roads
- }: C4 N' W& A1 P& @- K* ` green-light-up? ;; true if the green light is above the intersection. otherwise, false.
& x! d6 k& Z5 a" B {0 z6 M! U ;; false for a non-intersection patches.3 `' w# y1 z! O+ M( S
my-row ;; the row of the intersection counting from the upper left corner of the
( I$ T9 U! b% q% _3 @: b ;; world. -1 for non-intersection patches. b$ o; V# g5 [: G; e: [ K
my-column ;; the column of the intersection counting from the upper left corner of the7 S. G. E/ d; L" m# X4 {
;; world. -1 for non-intersection patches.
' U8 w& ^; y8 U0 q$ a% z my-phase ;; the phase for the intersection. -1 for non-intersection patches.
8 R' C! s3 i2 \ ^: u; q+ t1 p auto? ;; whether or not this intersection will switch automatically.* s8 S( w& U: T7 E
;; false for non-intersection patches.3 }( U+ A6 U [7 D5 a
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. @% `( L5 {% i% o& l) W;;;;;;;;;;;;;;;;;;;;;;
) }( u& o+ \8 a( G: H;; Setup Procedures ;;2 C. S0 A- a+ d' G+ n2 n
;;;;;;;;;;;;;;;;;;;;;;; C3 C* b: I3 \3 j& [. w
" ~0 l7 F9 S H( U;; Initialize the display by giving the global and patch variables initial values.
( l% y- |1 L8 y+ Z6 w;; Create num-cars of turtles if there are enough road patches for one turtle to7 O/ O) H7 m& T/ C6 X5 D
;; be created per road patch. Set up the plots.
/ Y, n; _# f% r+ Rto setup( f# I) _9 T2 z/ M9 r$ y
ca
/ C5 X; f' b% [7 S Z% f' ` setup-globals
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& h; d; P/ [' y: J$ U$ m _ ;; First we ask the patches to draw themselves and set up a few variables
; ]1 v9 d3 }" N) D. p3 w' }$ ^ setup-patches
% X; |& M0 X% ^ make-current one-of intersections
2 @9 `' _+ x0 F. f+ Y' n1 S 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 "
8 T9 M, j& Z8 ?/ I( z: \6 D+ E "road. Either increase the amount of roads "
N- A% m% H* M2 b, L1 r" i "by increasing the GRID-SIZE-X or "
/ S/ R- E/ X3 l/ P1 j0 t "GRID-SIZE-Y sliders, or decrease the "
6 V: x$ i& j2 t0 t7 d "number of cars by lowering the NUMBER slider.\n") Z& N) S7 w; }- }
"The setup has stopped.")7 f, V' q; \5 k$ t/ c1 r
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color2 c+ [# U" `7 M0 p0 J6 ^
crt num-cars/ V. M/ Z% ]* i- A1 C! R
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setup-cars
% Y6 `6 }5 X9 |3 ?4 R set-car-color
8 G1 q! [9 ^: D6 v record-data
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9 w# } @$ g% P9 {( {; u. x7 I) i ;; give the turtles an initial speed/ [2 l# l& g8 U8 `5 F
ask turtles [ set-car-speed ]
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6 I: r. y6 I/ N% ^9 B reset-ticks; ~. k0 W- _; U7 ]5 e
end
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) w. ~( s) U* J; Z# ]$ @$ i. v7 w2 D6 ^;; Initialize the global variables to appropriate values
7 `2 X' f1 }8 h! s( X4 F. gto setup-globals; k* I* W* l9 D, n3 b4 E
set current-light nobody ;; just for now, since there are no lights yet! k5 W5 Z" J8 h$ o4 ^
set phase 04 G: l: c/ A9 c( A
set num-cars-stopped 0& L$ E* r7 N9 q( D' u. a4 w
set grid-x-inc world-width / grid-size-x
) `( r) r1 `/ y/ l8 E 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( c* N1 s5 Y3 q1 u: H$ \
set acceleration 0.099# c; }3 ]) W9 j6 e: v0 u
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,+ M- a# y- ?$ ~: K' M: a
;; and initialize the traffic lights to one setting+ r0 o B i# I3 V# T# L2 T
to setup-patches. F& t/ D3 l+ l% f3 t+ l M0 |
;; initialize the patch-owned variables and color the patches to a base-color
2 L4 j" x8 J, b0 I0 r; ^ ask patches) z$ z, ]& x6 E
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set intersection? false
3 J" {6 M( }+ ?" r2 A: Z$ ]- P set auto? false- `' s. s* ~" [+ V" C/ }+ z2 d
set green-light-up? true+ Q! O% v! {$ g) p# I( y4 ]' y+ S
set my-row -1
9 ]4 [! q; B( j& U3 i8 ^& F set my-column -14 f& s# D2 O q5 V& n
set my-phase -1. C, z5 V. K+ e# `, x1 J" Y
set pcolor brown + 3' t& N' @" p0 M2 A, Y8 ]1 k
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}) N, E: s5 C; h. e ;; initialize the global variables that hold patch agentsets& [! m- z1 Z. ]/ ^& ?$ M
set roads patches with
# p+ o- ^7 A; j) B5 M) e y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or/ E' P7 f1 J G3 Q/ s3 j
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 C: a2 V* e! t( @
set intersections roads with- H: P' E8 \2 Z1 ]6 z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
C% S$ s& @, w7 P. X7 ` (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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9 c- M$ T, O# M5 c) n* a ask roads [ set pcolor white ]
! ~8 ~- h8 I2 D setup-intersections; o8 F0 Y( Z0 c
end) y% F3 _1 P& a
其中定义道路的句子,如下所示,是什么意思啊?% m) Y, F( K3 ~1 k
set roads patches with; Z2 `# S( r& a$ W
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 Z$ m4 A# a9 d5 I4 D (floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 I$ C* I) j9 P9 N; @. q8 v; a
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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