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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。
/ k" ~& P+ G0 s0 D7 mnetlogo自带的social science--traffic grid这一例子当中,' h5 P8 \# K7 E- g& W
globals
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5 u+ Z. z- L: u( ^2 I9 ?, F( ^ grid-x-inc ;; the amount of patches in between two roads in the x direction
8 d& M+ Y1 ?+ ^$ F& c! ` grid-y-inc ;; the amount of patches in between two roads in the y direction7 z" J, ~6 s9 U
acceleration ;; the constant that controls how much a car speeds up or slows down by if$ a/ |* g v7 U1 K1 _6 `
;; it is to accelerate or decelerate5 \9 ^; l) Y- R$ ?# b
phase ;; keeps track of the phase8 f* s( j. a5 i6 i% K' M# W
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
8 h3 g T& s% ]; [* o current-light ;; the currently selected light& R4 p4 n, a6 z; k2 y, Y5 @
U" @) {# O: k5 `) q ;; patch agentsets
6 X3 C; e$ t5 t! @9 z$ X intersections ;; agentset containing the patches that are intersections
9 X, n: G4 K: w8 K4 W roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle
( K4 l8 F* _4 a8 B: k up-car? ;; true if the turtle moves downwards and false if it moves to the right
$ s- v# r" ~9 X' E wait-time ;; the amount of time since the last time a turtle has moved
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1 F V# p5 z5 }3 s: H3 zpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
$ H' u. }0 ]0 P! V green-light-up? ;; true if the green light is above the intersection. otherwise, false.
6 @; s5 S0 J; a% f+ a; L ;; false for a non-intersection patches.
7 V* e+ r& x9 m! Q; A* x1 B my-row ;; the row of the intersection counting from the upper left corner of the% C% A. v6 s4 n( ]. N- Q/ G
;; world. -1 for non-intersection patches.
1 O6 y- t( |- F4 c1 M5 J' s my-column ;; the column of the intersection counting from the upper left corner of the" z7 a% w* j$ N9 @
;; world. -1 for non-intersection patches.
2 I( X$ Z3 ]5 z my-phase ;; the phase for the intersection. -1 for non-intersection patches.$ W0 Z8 T( y' m0 M1 x5 q. x' G
auto? ;; whether or not this intersection will switch automatically.* Y$ q' M8 x/ v, x8 n1 j6 i
;; false for non-intersection patches., n9 y9 @. O6 k8 _, A" @7 g
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;;;;;;;;;;;;;;;;;;;;;;
0 J$ @9 T- Y/ B$ | p1 g+ Z7 v;; Setup Procedures ;;
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) F. \* F- R' D;; Initialize the display by giving the global and patch variables initial values.
4 A* R5 K! J9 K! b# _9 c3 `;; Create num-cars of turtles if there are enough road patches for one turtle to6 A* F4 `+ {) h H' c& C1 r
;; be created per road patch. Set up the plots.! m, }" K1 m* c6 Z& n0 ^2 }& h! o
to setup
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
0 c6 S, _: O0 Q5 F/ o) j/ X, \ setup-patches
% b- ?; n* ^' Y6 k" i$ l9 i6 | w make-current one-of intersections
7 L5 G$ v! Y/ F; A label-current: ^0 f. }6 U% p2 ~3 @% w) S7 V0 _7 ?
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set-default-shape turtles "car"
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/ W% Z& \. w+ S( G, ~5 I if (num-cars > count roads)
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& }$ g# k# N0 h) t user-message (word "There are too many cars for the amount of "
# C5 ~9 r; `. _% B" b "road. Either increase the amount of roads "$ x5 Z( u6 p& ]9 o. z
"by increasing the GRID-SIZE-X or "
/ |$ D' Q4 i, n4 {. D7 m4 b% Y "GRID-SIZE-Y sliders, or decrease the "! T0 ]( f: Z, q. [$ c' J
"number of cars by lowering the NUMBER slider.\n"
: i+ A5 W1 d; u1 w# L "The setup has stopped.")
0 s& y# @5 ]: ?9 t$ G stop+ A' z0 n- e3 Y; g. N! V% j6 Y
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color, {9 a+ {6 ^# V: O( s- ?7 g
crt num-cars3 z% E4 y! Q6 J% P q
[
. O6 e, q9 Y$ I% b- p+ `% X7 C setup-cars2 C! o4 {% s p- e
set-car-color
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5 [/ | K+ I* p ;; give the turtles an initial speed
8 N; }( j" m) a: z1 Y5 e% R' s ask turtles [ set-car-speed ]
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/ n' _ ^4 _6 ~$ ~; r( A& Y reset-ticks
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& H$ }- ^* P8 M) M9 H;; Initialize the global variables to appropriate values3 `8 p+ K& ]: T* w+ x/ D! @0 x
to setup-globals5 D) E3 x7 f+ ^/ n3 T
set current-light nobody ;; just for now, since there are no lights yet( t, X; d5 r: t M3 F7 c4 t
set phase 0# u0 E: \. J9 S9 ^! c! g! |
set num-cars-stopped 0% c3 ] V" M. z
set grid-x-inc world-width / grid-size-x
/ y2 N7 _: y/ d8 j& J7 W% s. @# W9 p set grid-y-inc world-height / grid-size-y
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* |" y* k2 Q1 U o+ X ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary! c1 z1 [6 j5 ?- }* ~
set acceleration 0.0999 ^- S) Y$ L" `$ }: m3 d1 K. S
end
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' J3 X' E6 l4 i- P2 X;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
0 u1 n! p% L0 l- M: ^;; and initialize the traffic lights to one setting
+ C8 N$ m1 ?8 ?* ^2 lto setup-patches0 t% x/ @2 t( ]! b- w' x- t/ N+ {
;; initialize the patch-owned variables and color the patches to a base-color% b6 z8 F& [4 Q, Y7 E, f' Z
ask patches D2 ]9 o5 ]5 i9 z$ P
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set intersection? false; b, z4 d- U- b' ~7 O b
set auto? false4 Y9 S3 y" D# A+ v- A0 c# \8 M
set green-light-up? true( B7 N6 Q! u. |1 B/ U, F, K! t
set my-row -1
3 f. h. F2 D/ T: ]$ F) v set my-column -13 p8 H7 J2 e3 n2 N9 L
set my-phase -1# g% z, H1 R" M* ]' V. |( b1 Z
set pcolor brown + 30 e! n$ K1 _; H J. ~! j5 Q# }/ d% w
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;; initialize the global variables that hold patch agentsets M2 ~' `/ r0 g, Q8 ^- e3 r2 A0 w+ \
set roads patches with9 m4 o! \4 _1 r1 p5 Y. |3 w
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 u7 g% U1 r+ a4 h8 J# R+ t+ k2 }
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 X8 U( m- G% }, |1 h
set intersections roads with
2 i/ n$ r) [' J$ i7 B* _ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and4 b. R# H% \4 m% Y3 @: k- I
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 C0 P# [& r X: F
0 f" V+ Z+ A% e: C ask roads [ set pcolor white ]
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end
) o8 H# Y, o$ f* P2 ^( Y" L其中定义道路的句子,如下所示,是什么意思啊?
( E# n B! x8 d9 b7 y set roads patches with& d* l- N9 c$ t+ l( [: X
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or/ B u5 n% |' k* z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 }& c* K) q3 w6 i: w3 u
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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