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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。9 d3 q- g; V- _3 G4 Y
netlogo自带的social science--traffic grid这一例子当中,
% W3 w5 M6 G+ O( ]globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
" }2 B. ]: W7 \# E5 x7 ] grid-y-inc ;; the amount of patches in between two roads in the y direction
3 `( b6 U, B8 u" t7 J$ c acceleration ;; the constant that controls how much a car speeds up or slows down by if
! |0 u, s& E) Z ;; it is to accelerate or decelerate% c E `: D' A8 l% y. q
phase ;; keeps track of the phase+ U6 O6 B) E2 W- I
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
0 v# e3 Q3 s2 D: Z current-light ;; the currently selected light" S* e: `) z( A
* W& w4 K1 g) i4 C) g" _
;; patch agentsets1 W' J+ E. ~& Q1 }4 J) c
intersections ;; agentset containing the patches that are intersections
! U$ X* M0 u; T' P+ H' m. Q& f roads ;; agentset containing the patches that are roads8 L8 u+ _! t- |7 c! [
]
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turtles-own
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8 t f9 z$ x! R7 F% C. u& b speed ;; the speed of the turtle$ D6 e3 k- m \; h7 m& c
up-car? ;; true if the turtle moves downwards and false if it moves to the right# z0 j# w a$ I* y+ [% A4 U
wait-time ;; the amount of time since the last time a turtle has moved5 \, m% m0 @$ w- @7 a9 P
]
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* G% [/ V4 r1 G4 w9 y) q+ Z9 epatches-own
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7 r" f( _* l8 t1 `. L" j6 y) D( P intersection? ;; true if the patch is at the intersection of two roads/ g+ b1 Q0 d1 Q" R( W; ?! ^
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
7 h2 o/ @& x4 A( J1 ~ ;; false for a non-intersection patches.+ b; X( l$ C% D' P
my-row ;; the row of the intersection counting from the upper left corner of the* ~8 ?0 D% D# y1 ?8 Z
;; world. -1 for non-intersection patches.( |8 C* k% a( k# m- k
my-column ;; the column of the intersection counting from the upper left corner of the
$ M, N- P; }: Q& b3 z ;; world. -1 for non-intersection patches.; E; n* |( i3 s3 V
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
$ e5 M9 T* |* n auto? ;; whether or not this intersection will switch automatically.: b) t; d4 W1 q
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
' ?! D" K& I. V' V, K2 [;; Setup Procedures ;;
: U+ J1 `* L; v2 f;;;;;;;;;;;;;;;;;;;;;;5 W% {% x9 f G2 \6 p- T& H
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;; Initialize the display by giving the global and patch variables initial values.$ b( [- j8 K/ D7 J' X
;; Create num-cars of turtles if there are enough road patches for one turtle to
+ l4 i# T) [8 Z6 l, c" K;; be created per road patch. Set up the plots.% N& |! T9 _4 m0 @' h) l
to setup @# ] R6 s. z% n5 {& y) P
ca
$ p# z m, G1 c, `9 M; D+ t setup-globals& M7 w& J2 R. Z `5 d
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;; First we ask the patches to draw themselves and set up a few variables X$ q) M: P3 n. U! I* |
setup-patches
% @& H) S' M+ g6 r( z% u make-current one-of intersections
, ^' _" A: O, m label-current
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set-default-shape turtles "car"
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0 ~! C) q7 |" j" j8 F if (num-cars > count roads)
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7 d: f8 S- w7 o* ` user-message (word "There are too many cars for the amount of "
8 w+ J3 d4 _ S7 ], r "road. Either increase the amount of roads "
$ O+ L+ k6 n' e3 `- {+ o' `! l "by increasing the GRID-SIZE-X or "
, e5 W/ \6 @. C& ^ "GRID-SIZE-Y sliders, or decrease the "6 }- T" v$ e) U W) f) v3 ]7 b
"number of cars by lowering the NUMBER slider.\n"
0 L/ A4 R& K1 z; }# O* `1 L "The setup has stopped.")! u; D# c" [' g, a: h! w& C
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
( V6 ?& Q% ?& f; f$ h& q/ O* D crt num-cars
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setup-cars
6 a* [% X! d& c$ f8 t% l q set-car-color) S: i6 b2 a) u0 l
record-data
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;; give the turtles an initial speed
% x ?6 c5 F8 c2 j ask turtles [ set-car-speed ]7 w# X3 S ^" A) R$ H p. g
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reset-ticks L( f: P$ Y5 X1 b
end4 g; Z4 x- @! n, c8 P# t8 x; t6 t" L3 K
* L' H, e: e7 b) k1 r- n6 n;; Initialize the global variables to appropriate values# h# s! r! L) V- a. ?9 ]& I' R& x
to setup-globals# w7 P8 P V, v* D9 r1 W/ k4 m6 _
set current-light nobody ;; just for now, since there are no lights yet: Y& e7 c4 V$ ]& Y
set phase 0: S! C8 V8 o+ B1 K
set num-cars-stopped 05 W# T5 p* T% Z2 w g
set grid-x-inc world-width / grid-size-x- ?' Q7 Y& a) V
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
5 D6 p) x9 j1 e/ |# E set acceleration 0.099
! D. r0 |" a7 fend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,6 m* c$ ]( s: `5 E9 z' U& H: p4 K
;; and initialize the traffic lights to one setting
* L+ K8 I1 q1 V& |6 `8 Ato setup-patches
0 G! H p8 q' Q6 ]: s/ D5 P" c ;; initialize the patch-owned variables and color the patches to a base-color5 M4 f, z# X" L, ?6 \" {- M2 Y
ask patches
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set intersection? false: N0 U3 ~, N ]) \+ i! E6 [ x9 G0 B
set auto? false7 r5 f) U& ?% W. i
set green-light-up? true; I# w" Z+ q* e, a i
set my-row -19 e3 o$ l. m u5 a% \$ k* i$ h6 Y
set my-column -19 Q+ `8 V4 q v
set my-phase -1
. W; Z. R1 p( D* t; _* p% m set pcolor brown + 3! ?( p+ F% H" t6 w8 E" c2 x- R
]
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$ x# y$ W0 B) ~. N" e. C6 N ;; initialize the global variables that hold patch agentsets( a4 ?; T; f0 u2 D e7 p! b
set roads patches with
- c% n: v" z3 j' }+ r9 _ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" L" g# F/ X! L9 s* z# j! g
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]& I6 @& e8 ?( @+ I: h, S
set intersections roads with8 _ ?9 z5 r/ ]( w6 _) w, D
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and# X5 W8 K3 O3 D' y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
% u: f1 _; q( F) H4 Z1 w/ Q5 q setup-intersections; Y4 [( f- U- L. N) M1 x
end
; g, \% I& D" O1 f: r8 y其中定义道路的句子,如下所示,是什么意思啊?: c6 _8 B; V1 X- Q A
set roads patches with( |7 v# C# ]- T. u, P9 n! K2 U. l3 \* j$ x
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: r) g g4 b, E R# ? (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, a7 s- [7 ?, H0 O9 \8 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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