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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。' Y$ y8 X: b+ a; q6 E
netlogo自带的social science--traffic grid这一例子当中,$ c. N1 M/ q: W! N6 K
globals
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9 \/ `$ X$ }; M2 c& p& K$ V grid-x-inc ;; the amount of patches in between two roads in the x direction# ]3 l7 t9 m2 z3 h5 c8 s! v
grid-y-inc ;; the amount of patches in between two roads in the y direction1 m3 x! {! s( z3 ]
acceleration ;; the constant that controls how much a car speeds up or slows down by if
0 v! A# b! t% d3 N ;; it is to accelerate or decelerate
6 m. n* J" E& r phase ;; keeps track of the phase5 J# ]8 P" n1 r
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
6 `( V! R" A4 x0 j1 g; ] current-light ;; the currently selected light. Q, s5 _" l: j1 I9 j+ K
# W6 r" E& m8 P# b! U7 t' [6 x ;; patch agentsets2 r+ p1 H3 ^1 ]- G5 V, S
intersections ;; agentset containing the patches that are intersections" F; l6 j! y" V: w( m7 G& ^+ t
roads ;; agentset containing the patches that are roads* T+ P3 h7 q0 V3 a$ `
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8 i W; P' G) @3 [1 Bturtles-own* p7 A' S! D( c) E6 u5 R
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* Z% y" r g- r1 i speed ;; the speed of the turtle
* e) c0 l5 c3 r( u/ }6 K up-car? ;; true if the turtle moves downwards and false if it moves to the right
, @+ s) j, T5 r/ f wait-time ;; the amount of time since the last time a turtle has moved: O! v" i, t& i5 k* o" H
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$ W6 }) ^) q3 e. p; x6 S: B4 O. |% t+ Dpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
/ }# U$ U) m. Q- }' J( `+ n, U green-light-up? ;; true if the green light is above the intersection. otherwise, false.2 v4 \+ y/ n) S6 G
;; false for a non-intersection patches.3 }5 f4 c6 m. w, V. @
my-row ;; the row of the intersection counting from the upper left corner of the
" t1 L0 m4 ]+ v: E8 u, X ;; world. -1 for non-intersection patches.
/ }. c4 V! c" ?7 O my-column ;; the column of the intersection counting from the upper left corner of the& E, F' q# u ~1 t' M
;; world. -1 for non-intersection patches.
- t6 h% v* W# ?6 ^) Z9 ]5 G! R( R my-phase ;; the phase for the intersection. -1 for non-intersection patches.! }, n1 z0 X* Q
auto? ;; whether or not this intersection will switch automatically.1 \0 z0 ]1 [: H9 n
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;5 n4 f: O0 O. \, P! U
;; Setup Procedures ;;
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4 L, t: t2 R/ t* W; a: {6 n;; Initialize the display by giving the global and patch variables initial values.
+ k7 ]6 i+ b' ]6 V) M. @! M;; Create num-cars of turtles if there are enough road patches for one turtle to$ y o/ f" Y2 ^2 U
;; be created per road patch. Set up the plots.
! K8 s! A0 C2 e" ^, h& Uto setup
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setup-globals9 E$ H' ^+ t+ B% X" ^; G
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;; First we ask the patches to draw themselves and set up a few variables! k* R$ ?% t l( q" N. O5 U, ?0 ~
setup-patches. d) P2 G5 c) t' A( J* E5 @- n
make-current one-of intersections
) q! f1 T( U- q+ k label-current" ?% p1 F6 @0 A. F" v+ x/ C
4 |8 o6 y7 J) }5 W6 h* N set-default-shape turtles "car"- V2 q9 N8 i3 t* p1 v+ |9 f/ w
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if (num-cars > count roads)$ g z h7 v4 E4 P* g% a! d
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user-message (word "There are too many cars for the amount of "
( A7 v. Z( F) i5 R/ G- M6 G "road. Either increase the amount of roads "; b/ L4 o. i7 I# J
"by increasing the GRID-SIZE-X or "7 }( j1 u: U* p9 a, Z; c" |8 X: S0 A1 a
"GRID-SIZE-Y sliders, or decrease the "
& ~$ Y% s5 a9 Z8 `0 x1 g "number of cars by lowering the NUMBER slider.\n"
9 m4 q, m! _+ _6 T: n" s "The setup has stopped.")
/ G9 O6 [; F. N; w S stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
6 I5 p; Z4 o5 Q" B7 X crt num-cars: ]; Z# Y* w* X9 x7 R7 x
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+ i( c l Z0 d Y1 X& z setup-cars# \" [1 k, |3 D4 _0 a
set-car-color
* y8 |* v& a7 t" ` record-data/ z) U8 G f% L/ V9 R" N
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6 Y2 l5 C) A4 q5 {" V1 t L# a ;; give the turtles an initial speed& A) @; ~# k5 z0 J
ask turtles [ set-car-speed ]" O! Y% a7 I1 J& t0 ]
$ m6 b6 F4 g# z6 g8 H5 ? reset-ticks8 H+ {9 P6 x" d" v% h
end
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' r: X* p4 C! D% i$ a: S' B;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet P0 c; O- Z$ {8 L
set phase 0
; F' F9 ?) X" _* K set num-cars-stopped 0
+ r% I, J0 I+ |; B+ N set grid-x-inc world-width / grid-size-x! t1 `- E, w+ V+ q3 h/ O) B% X
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) d1 z9 r$ ?; G5 h3 k7 e
set acceleration 0.099
2 t$ r& r$ m$ f5 Y& {& ?end: D5 Y9 R a' y0 A
" S) f3 f, f( L& ]' O1 [% i;; Make the patches have appropriate colors, set up the roads and intersections agentsets,2 L9 ^4 Q# D7 S: j
;; and initialize the traffic lights to one setting3 o% u0 h) f' R9 V' [: ~
to setup-patches) I( _8 \+ V3 n: _* Z4 N9 }
;; initialize the patch-owned variables and color the patches to a base-color
- D' P+ K! K( U/ D ask patches
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set intersection? false
, S$ ]( g4 O: R8 b K set auto? false/ c! |* d# C1 Z# j* J2 B
set green-light-up? true
$ W `' f( ^+ h v1 t5 a set my-row -1
7 t; D+ D3 e0 d# \& F# h set my-column -1
! s |9 k9 g0 D% ]( E! q set my-phase -1 A8 ~" X8 v% F
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets+ e c2 W" m) m1 M9 h% R3 U" G/ }' y
set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 h J/ `# b8 u4 x7 s: Y set intersections roads with( n$ ?0 @0 v1 ~
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and! V o H, e0 e
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]# b" a' ?$ ^! @8 g% b3 Z% z8 K6 w
setup-intersections
7 D% ~ K. P G2 P1 J8 zend
6 i- c- J$ @. e. e ^$ q其中定义道路的句子,如下所示,是什么意思啊?- ]& W; P4 ]- s k* F+ B( @6 g
set roads patches with
4 G5 t" ~6 a3 H% ^. ~; L* y+ k; x [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 a# e: M. s6 \' P3 ` x3 u (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 ~ h2 o4 K3 V0 A! v* E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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