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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。
/ g9 z& d) U3 N+ |9 {2 p$ nnetlogo自带的social science--traffic grid这一例子当中,
( r7 M3 k# x( ]1 z0 K2 Qglobals
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5 w# E6 ^ D* |7 W, g grid-x-inc ;; the amount of patches in between two roads in the x direction+ i S( X8 z6 q6 [( w2 d
grid-y-inc ;; the amount of patches in between two roads in the y direction
2 @4 Q6 |) B) G. P3 Y acceleration ;; the constant that controls how much a car speeds up or slows down by if, {4 i1 \& F, b/ a) S/ R+ n2 u! L3 ?
;; it is to accelerate or decelerate! g2 F# O0 X1 E _ ^
phase ;; keeps track of the phase4 A& S& r& z8 ?! F% h1 M) J
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
! H3 t, l, ]- c! ~/ p" a- I+ V current-light ;; the currently selected light
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T2 g w+ B/ q8 k ;; patch agentsets
8 l' c( ^7 k# @ intersections ;; agentset containing the patches that are intersections+ q% W, S9 V* F
roads ;; agentset containing the patches that are roads
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# W8 h: u3 [2 O* _1 m6 h) m# o7 @6 tturtles-own4 T8 q$ D5 d( U' [+ G; `
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speed ;; the speed of the turtle2 J2 ^2 p: n7 @: Q5 }
up-car? ;; true if the turtle moves downwards and false if it moves to the right
3 h& w" n3 s9 m8 j+ x! g( @. w+ q% A wait-time ;; the amount of time since the last time a turtle has moved' o) ^) _; n, V9 l3 s) q9 y, [# X/ g
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
& ]8 H& k8 j6 u green-light-up? ;; true if the green light is above the intersection. otherwise, false.
6 S8 M$ d3 H- t ;; false for a non-intersection patches.
6 [/ Y0 q; N+ j1 x# B# ]# \ my-row ;; the row of the intersection counting from the upper left corner of the
6 T% Q! _( x! G: { ;; world. -1 for non-intersection patches.
/ p& c( B6 Q3 \8 V% I. n( H# } my-column ;; the column of the intersection counting from the upper left corner of the! X. {# k1 b# J% c
;; world. -1 for non-intersection patches.
( Z ]( ]! l' A# w W2 \ my-phase ;; the phase for the intersection. -1 for non-intersection patches.! A9 O& b% g" i9 s* x2 a
auto? ;; whether or not this intersection will switch automatically.
" \) f, ]% U5 f+ R, ]0 Y5 y# @4 a ;; false for non-intersection patches.: d9 u% ~4 i# y4 G6 D. y4 `; ~( k) p
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;;;;;;;;;;;;;;;;;;;;;;
' F A, _* C$ ? }- i;; Setup Procedures ;;" U' [' N; c8 J% u! R( l% d
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.! X! n7 J! `& i
;; Create num-cars of turtles if there are enough road patches for one turtle to7 I$ e5 @6 x' ~4 |4 w5 T
;; be created per road patch. Set up the plots.( z% K! ^, r3 A4 n. I( z
to setup8 T! F1 @& f8 m: F4 q) S
ca
5 l3 `( A1 k# P0 Q g# C/ ]8 M6 i setup-globals( ^7 n8 u/ Q- _5 _( ^+ A& r
3 e7 k( @1 o' @* n ;; First we ask the patches to draw themselves and set up a few variables; E9 ^. j8 n6 P5 T
setup-patches6 g: Z" \( q' L
make-current one-of intersections/ F s% M' L9 g* u, e1 w4 `: z
label-current
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0 L' Z& N$ N' J2 } set-default-shape turtles "car"+ s' E5 s1 i2 A5 k
2 [ j" S* L6 n4 ~. |1 H% O; O if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
" j. U; a% S: N- n "road. Either increase the amount of roads "
; w$ t& j% k) o "by increasing the GRID-SIZE-X or "
4 F) h, Z9 I \( E5 w "GRID-SIZE-Y sliders, or decrease the "* O! m3 Y3 @. A. k
"number of cars by lowering the NUMBER slider.\n"
3 c* i' G( {6 z* X, i/ ^* p "The setup has stopped.")
' G; D: M2 j/ ?' ~+ v A stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
- {: @" J8 u+ L0 D crt num-cars
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setup-cars( P* f8 y1 y2 K
set-car-color
; S6 J9 U6 i3 H$ ^* ~/ C record-data
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( e$ ?: z9 U6 C2 [8 U ;; give the turtles an initial speed( \# w7 Q/ @/ L' G, d
ask turtles [ set-car-speed ]7 k1 ?7 w( v/ z: N, k
8 _5 W u9 M% R4 P( B reset-ticks9 E: {$ s1 H$ s* X. z. T
end0 X4 Z ~" w5 u1 Q1 o5 s I
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;; Initialize the global variables to appropriate values
) T: t4 c; r; g$ Rto setup-globals
) b6 o$ S4 h b4 y9 v7 K8 o set current-light nobody ;; just for now, since there are no lights yet
( C8 P5 F# Q* U$ {1 l* L5 T" e set phase 0
/ m& o0 w: h& u set num-cars-stopped 0
. _2 R/ E" K3 y' c, ] set grid-x-inc world-width / grid-size-x5 g# Y& ^7 V3 t5 u4 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
Q+ R. v; H9 k set acceleration 0.099
2 j7 H @8 q- {. U/ Oend
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5 R7 g3 S- |3 l, l; S;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
* ?" }" n3 f6 d;; and initialize the traffic lights to one setting
8 \% y" Q3 M1 v+ lto setup-patches
& P# l% E; L5 B# k+ B ;; initialize the patch-owned variables and color the patches to a base-color
4 ]$ v# L6 `* ` ask patches- y# G# G7 N5 p# n8 N
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6 I% C# f, Y' V* h) p set intersection? false5 O( L) X! P% s* L
set auto? false; Q8 P1 w& o0 f' C
set green-light-up? true! L" H# B5 V* s# g( M
set my-row -1
; U& {: H4 j% s; n9 T9 n set my-column -1
1 D$ p# y' c: z! X& s9 w/ h set my-phase -1* e( N7 E. p% e$ J0 {
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets( D( \, V9 Y" d) _
set roads patches with* b6 K3 I4 H8 [
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" c' i4 t: I) b% k( ` (floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 G! ]( Y; Y- E. J5 |. |' K' k% x
set intersections roads with
7 Z& T) `% \; \$ K [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
. x4 b8 k% F$ S- [% g (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]2 t8 P8 q' o2 K
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?( ^; R5 {6 |0 L
set roads patches with0 w2 p5 Q) T. C6 I8 a2 `" G
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* T# n; y% m& r# V- l (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 H: b: M2 |. X* f& K; s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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