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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。* x Q& G# k2 P2 U
netlogo自带的social science--traffic grid这一例子当中,
$ Q% v7 f3 w$ Q R: E3 h0 iglobals$ ^4 P* w1 a9 s' g, R6 r: H/ g( X. o
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grid-x-inc ;; the amount of patches in between two roads in the x direction
3 [3 @7 d; `! C- d* [8 H+ A7 _8 R grid-y-inc ;; the amount of patches in between two roads in the y direction
5 M2 G9 u9 a1 D' c; @0 f acceleration ;; the constant that controls how much a car speeds up or slows down by if; P( @7 t5 U* X
;; it is to accelerate or decelerate
% x6 Q' C! b: a% P phase ;; keeps track of the phase
U/ F0 o C( X+ p5 T num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
" {5 [& ?* H# k2 d) e( x current-light ;; the currently selected light
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;; patch agentsets% V- Q+ S5 h, w8 I
intersections ;; agentset containing the patches that are intersections
6 u, p9 V8 t( U% f1 @2 U1 I- j& u roads ;; agentset containing the patches that are roads
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turtles-own
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0 h4 J1 [- P+ V& V( ?1 E+ f speed ;; the speed of the turtle7 n( i! O+ S, S* j8 ^
up-car? ;; true if the turtle moves downwards and false if it moves to the right
7 P8 ?) b- |% T4 R+ I% t1 k wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads0 c% k! ?( D( z% F5 i. k7 y! N# }
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
U' W- m- {4 f. h) S6 { ;; false for a non-intersection patches.
. g9 l7 o) {/ `* N: s my-row ;; the row of the intersection counting from the upper left corner of the* Y+ a6 g5 n, w. U
;; world. -1 for non-intersection patches.% t3 S! T' }8 K% m$ y
my-column ;; the column of the intersection counting from the upper left corner of the* U$ b( `( Q* g5 K" C/ s& G( Z0 d
;; world. -1 for non-intersection patches.
! }+ j/ U9 P0 _ my-phase ;; the phase for the intersection. -1 for non-intersection patches.
+ n n) R5 j }6 |/ j auto? ;; whether or not this intersection will switch automatically.
% e) ?0 z- y* |0 z ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
- i. q9 h2 ~1 N" T;; Setup Procedures ;;
+ J: H+ \/ ?) U6 }' H( F9 p( I;;;;;;;;;;;;;;;;;;;;;;
* j! F3 M/ C1 p3 w
" Q+ T4 G8 q0 N+ c g;; Initialize the display by giving the global and patch variables initial values.' a$ C5 U' c, L3 @8 |/ }
;; Create num-cars of turtles if there are enough road patches for one turtle to+ z0 J3 K' o) i- G% k
;; be created per road patch. Set up the plots.
& P; ^. { `( h. V. m% w& uto setup6 r, h" p- F" n4 b& Z7 p
ca
6 L' T4 Z3 {) _1 w+ X setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
, _* ]6 j; [2 g5 ~5 J7 K setup-patches
; |0 g) u$ }( h1 x% W) y. t9 C make-current one-of intersections" g8 s0 q: T6 ^) @1 I3 i
label-current
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set-default-shape turtles "car"7 u5 k! {7 D( c- z5 O' r& h
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if (num-cars > count roads)- Y3 f1 w: @# |5 X. b, @
[
6 z$ L T8 o" G* | user-message (word "There are too many cars for the amount of "
' O ^ e. f' m0 j "road. Either increase the amount of roads "
% |( L3 Z/ ^& q0 g "by increasing the GRID-SIZE-X or "$ _; a, f8 n5 @* c
"GRID-SIZE-Y sliders, or decrease the "
3 O- n$ s3 J' ?* u; a9 b' k "number of cars by lowering the NUMBER slider.\n"4 T R! w/ i. Q. o( w' L+ y
"The setup has stopped.")* y1 U+ U% P1 T6 l4 A2 o9 V
stop
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6 h8 {4 ^1 v! @: M; ^ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color' f4 I" J" N- K8 N; o: ^0 {
crt num-cars
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) m& A9 J& S0 V4 W+ B+ a setup-cars
0 D+ H! D6 K* K; g& y! O set-car-color
" d6 U+ ?; [. ~: p9 b3 c6 T record-data: c, @* |6 Q" Z* d; l
]
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! f, V; I) ^9 }, ~* k, [ M ;; give the turtles an initial speed9 I% _2 z3 T8 T$ w. h( w
ask turtles [ set-car-speed ]4 d) v) i8 V6 v. u* \- N
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reset-ticks1 T! C+ N: J4 E$ z
end% ]6 i" X/ L+ m1 s0 h+ B( f4 B
* [- v' Y; Z5 q$ f2 ^" G# s;; Initialize the global variables to appropriate values$ `" `" M2 [! l9 |
to setup-globals
, h+ K. J/ y0 n/ \" n4 [ set current-light nobody ;; just for now, since there are no lights yet# ~, b' p B: p# Z
set phase 0( C4 o4 b5 ?3 f# ?! P
set num-cars-stopped 0. S# }8 y- o- ]! t, d" r, {" E* N; v
set grid-x-inc world-width / grid-size-x* _. F1 h7 L _% d2 ]. y7 G
set grid-y-inc world-height / grid-size-y' L/ y1 [( z+ x5 }7 v5 u5 j
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
% i, P. s8 N. [0 A. W set acceleration 0.099
, E3 @+ g7 l3 x9 a! c# pend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,) [6 V* v* e% A. N0 l2 T% f& V9 H
;; and initialize the traffic lights to one setting
@4 h& a0 n. S; F/ C' U) w2 zto setup-patches
9 N6 A8 S% p O% L: f" L2 e4 r ;; initialize the patch-owned variables and color the patches to a base-color! ^$ I' m' Y" l! H# P
ask patches/ |/ l, i5 D: |% I2 n& U
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set intersection? false
2 }/ _, Q5 S. i0 G set auto? false5 ^. C, K" I! \( H. w5 w! a
set green-light-up? true$ F1 T8 H# k i
set my-row -1* o: W! M' t* `# C |+ A( ~
set my-column -1! h2 a2 V5 K, D) Q I
set my-phase -18 e4 O& |. N* M' b) |
set pcolor brown + 3# p E; C P- U3 p8 |; y7 A
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;; initialize the global variables that hold patch agentsets
$ l+ t! x2 z: t [- B set roads patches with
" G* P3 X h' ~5 D! @; @& M' N [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
H2 T. i, \' H# _0 R6 z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 h- i' `! D+ b7 [( M% o# z( d, { set intersections roads with. R2 C) s" M* v, b6 ^* S
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
$ ?' ~* q% b( X7 e* }$ e* Z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]" l3 V3 h4 x, m5 X
$ D! P* | A* G ask roads [ set pcolor white ]
$ I. ?2 s {4 a setup-intersections
I) J9 i& y; S8 ?3 q( E) Lend
' {3 Y" [7 l4 f$ Q3 Y; n J; q+ I其中定义道路的句子,如下所示,是什么意思啊?, A2 I1 O3 [2 w- |# Z5 l# d
set roads patches with
$ x0 L, \& `; l `2 D f [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 s+ h* j7 V# X6 _2 l# h (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 x6 l4 y6 S/ r2 P8 X, y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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