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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。
4 e/ o5 ?5 W9 ~/ K$ V0 a! C5 S' y5 enetlogo自带的social science--traffic grid这一例子当中,
& d8 E4 C! z4 q4 Z0 B( nglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
% r* b) Q6 V, J; b7 z$ S grid-y-inc ;; the amount of patches in between two roads in the y direction
$ t/ f: {! w& d6 N7 g% ?3 P) H- D3 m acceleration ;; the constant that controls how much a car speeds up or slows down by if( O( j& a B( V9 H( I
;; it is to accelerate or decelerate1 F Z2 ~) Q, j4 d+ m. b
phase ;; keeps track of the phase
/ J1 y! _0 L5 o [- K7 L9 a. V num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
( p- ^+ y8 r( @! v8 A/ W# [( J( } z current-light ;; the currently selected light' l$ T1 b" f( I, R( o; F+ g9 [
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;; patch agentsets
9 w! L7 B3 `4 }( v. w intersections ;; agentset containing the patches that are intersections% R: P6 v' `# i" ?
roads ;; agentset containing the patches that are roads
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turtles-own
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4 E& k4 q9 r; j: ~9 k- ] speed ;; the speed of the turtle
3 a( O2 T" }8 Y9 q! _3 | up-car? ;; true if the turtle moves downwards and false if it moves to the right3 w/ `; v" p3 T
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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7 D! s4 u5 B# u- \- I& o. L" h) @ intersection? ;; true if the patch is at the intersection of two roads
) h0 Q/ c b9 U3 [2 t green-light-up? ;; true if the green light is above the intersection. otherwise, false.
. K8 w z y/ u8 Q! h% S6 A ;; false for a non-intersection patches.9 Q' L% ~# ~) i; i5 r
my-row ;; the row of the intersection counting from the upper left corner of the' M& G# L9 Q: H: v8 e
;; world. -1 for non-intersection patches.0 d6 _ L8 w* W- b! J
my-column ;; the column of the intersection counting from the upper left corner of the
, \* I; e- a- g5 u! `6 \, E& \ ;; world. -1 for non-intersection patches.
4 N! W. S1 C/ g2 l) y6 E. i# P my-phase ;; the phase for the intersection. -1 for non-intersection patches.+ ~$ g% |) Z# K g
auto? ;; whether or not this intersection will switch automatically.
( T, R- `. [$ {) T4 q; F' F: E ;; false for non-intersection patches.9 q5 o: r9 G0 s# u) y: }! f& b
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;;;;;;;;;;;;;;;;;;;;;;& L# ?( K' Z& f( m
;; Setup Procedures ;;2 ?4 n3 t1 v# i- v( J7 e" D" R
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]" Y: r2 E( `;; Initialize the display by giving the global and patch variables initial values. W. F# ]8 {: T* b2 S& V0 h
;; Create num-cars of turtles if there are enough road patches for one turtle to
2 W1 @4 J/ y. d; V4 v;; be created per road patch. Set up the plots.
2 w, @' E' m0 L, ~% |- ~to setup9 e! r# a) F, n$ o0 n; `) b5 y& L
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setup-globals8 f4 U$ ^2 B, w/ |1 z8 d G1 M
1 P9 R! D0 d0 j W3 i. D: g( N- e) y, Y ;; First we ask the patches to draw themselves and set up a few variables# T$ V( y9 Z7 K1 w
setup-patches) B4 S; h4 c5 P! v# m
make-current one-of intersections+ e8 v; H8 Z+ f. ]0 G% ~
label-current- q6 K% V0 p' U2 M- E6 q
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set-default-shape turtles "car"9 |1 r- W3 h( s
: a4 {: s. G: W9 m+ W. Q# S3 T if (num-cars > count roads)
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/ i- B% w' B \) Z( [0 E4 W user-message (word "There are too many cars for the amount of " n0 w, [' A/ b2 P
"road. Either increase the amount of roads "
* C2 ?% s7 C# W "by increasing the GRID-SIZE-X or "3 ]4 B: c( E1 m$ b
"GRID-SIZE-Y sliders, or decrease the "
. V. x% y; t" D3 J "number of cars by lowering the NUMBER slider.\n"
" q X# t P( s9 { "The setup has stopped.")
# h X& _2 ^2 a2 r/ C stop' d8 x: L$ }" @. N2 F1 J5 d
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
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setup-cars) B& m4 z( T2 m" L' g+ K
set-car-color
( I2 C) N( V" b( c; \ record-data
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;; give the turtles an initial speed! [1 ], Y7 L9 m# ] |
ask turtles [ set-car-speed ]
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reset-ticks
$ R& P- l9 Q+ T' x/ Jend
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
# m* d8 ~2 w$ m' J set phase 0
$ y$ N3 x3 @! a& j ` set num-cars-stopped 06 j4 h: y0 j: V/ B/ ^1 r
set grid-x-inc world-width / grid-size-x& v# @+ p5 D/ F k/ h( {8 e) m
set grid-y-inc world-height / grid-size-y c: P' b: s2 P. e! L* C: J, P
$ `! [4 O" L+ p ~9 l7 F' @ ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary2 V! s9 ?; L( [
set acceleration 0.099, a6 k& v; Q* |/ C0 G2 V v D/ t
end
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C# e/ O; O; Q( k! Y;; Make the patches have appropriate colors, set up the roads and intersections agentsets,* }; D1 v- d, i4 L# l. d
;; and initialize the traffic lights to one setting
4 R4 t9 L. a& p1 Y8 E* Lto setup-patches9 @$ P% H; m+ P9 z
;; initialize the patch-owned variables and color the patches to a base-color
9 ]$ ]; ~2 Y4 ]& V ask patches: g! h- ~- @0 S# ^& [+ v c7 N( Z
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set intersection? false7 `: w4 B2 E; a, P) }! I
set auto? false
5 Q' W* F5 C5 ^! b7 L# Y set green-light-up? true. m* w0 R1 G. ]7 O
set my-row -1. {' U# P% ]( X
set my-column -1' v1 l2 p# I5 z; N: D0 o; [
set my-phase -1
( j( `1 ?2 z0 [) U+ i, e set pcolor brown + 33 X( i. ?1 E- L$ ^2 }1 ~
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;; initialize the global variables that hold patch agentsets
8 e0 d$ d+ R- x( u, n! }" ~) I+ ~ set roads patches with
9 J* [, j- [( N4 h" ]9 ? [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ L4 t1 H* y, v) f7 E. L (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ [# J, E# S7 f. \9 m6 t3 D& B set intersections roads with
( k6 W2 f: o2 q7 F$ ]/ \ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and3 }6 h# |8 X) x* w
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]' `* b+ @5 j- V/ ]3 `+ b
d9 Y6 Y1 p) @! k) X" b ask roads [ set pcolor white ]
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1 ^) T' v# I# W其中定义道路的句子,如下所示,是什么意思啊?
2 u( D" O& _2 E" ?% O+ b% p set roads patches with
* ?4 f: W8 x% { [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
W3 y* o2 H+ E" C3 i (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 v; N; A+ |8 r/ g1 E+ \. P+ I5 d! ]# ?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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