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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。
1 E- x# e$ z6 j$ n; w0 ? qnetlogo自带的social science--traffic grid这一例子当中,
' J+ G0 U! |4 D; y0 l0 Nglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
/ j" i* |0 }* t) P2 o% m# d grid-y-inc ;; the amount of patches in between two roads in the y direction- s* G3 s! m7 `9 M
acceleration ;; the constant that controls how much a car speeds up or slows down by if
: Z0 b8 u# I1 c! c1 R, O ;; it is to accelerate or decelerate
" N3 O3 C: ^( h( c M phase ;; keeps track of the phase
8 @& `+ K1 `2 T/ p5 v) B4 J3 A) V' P num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
* {' r T6 h/ p6 W& N current-light ;; the currently selected light
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2 V# `. Q1 |% ~* S# O ;; patch agentsets
2 `$ h/ |: V2 l intersections ;; agentset containing the patches that are intersections
T' U. [; G; H3 ?2 S2 r' m& C# L roads ;; agentset containing the patches that are roads
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7 ]! Z/ {: w+ U* S$ B" `- r& Yturtles-own) ?; p9 c& s1 c; J, v
[
7 T- V; D) b _/ V' P; I speed ;; the speed of the turtle
: y5 b5 n9 }3 |. I {( [* v up-car? ;; true if the turtle moves downwards and false if it moves to the right4 D4 Y1 Q8 m* [# }6 i
wait-time ;; the amount of time since the last time a turtle has moved/ w; f- j, P( E4 b3 J
]
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3 t' e5 ~2 K; Y( N) j9 t9 ypatches-own9 l6 `' N+ s9 ?" D( i
[- y/ H8 V6 i8 C$ q
intersection? ;; true if the patch is at the intersection of two roads
/ | d8 |3 b2 N6 l/ h5 s* e2 p green-light-up? ;; true if the green light is above the intersection. otherwise, false.
- t5 u% o. W4 S8 D: R* l# ?6 D! T- p3 j ;; false for a non-intersection patches.
5 U! h. J% \% ?, i6 d4 r my-row ;; the row of the intersection counting from the upper left corner of the8 @( A' f/ V5 i) @( w# q
;; world. -1 for non-intersection patches.4 v# a* W+ ]! n: [( V7 y
my-column ;; the column of the intersection counting from the upper left corner of the8 n! U' E6 n; h2 B3 _8 j
;; world. -1 for non-intersection patches.
! A% x# a9 e0 y6 f) V my-phase ;; the phase for the intersection. -1 for non-intersection patches.
. X; L" u* V6 T# w8 t. @6 V auto? ;; whether or not this intersection will switch automatically.
% _2 d: y+ i4 i0 w ;; false for non-intersection patches.6 q* h3 q% U6 h5 e# `
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2 W9 E' ?6 s3 Y1 {;;;;;;;;;;;;;;;;;;;;;;
% g$ t, j1 H, u;; Setup Procedures ;;% D$ s( u6 _% v' l
;;;;;;;;;;;;;;;;;;;;;;' ^3 @' J: ^0 n, t
) i: Z( m4 F; q$ {7 r/ ~% Y$ w;; Initialize the display by giving the global and patch variables initial values.
* S9 x* O& R) |) N;; Create num-cars of turtles if there are enough road patches for one turtle to# `# f8 O1 x7 G8 i0 o; G
;; be created per road patch. Set up the plots.* U: K, y$ s5 q: i
to setup( N% v$ @7 o' T S3 s7 x
ca
5 t- O- o- G, e" {: }/ e% N) R setup-globals9 Z! |1 \$ E9 Q6 u' D
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;; First we ask the patches to draw themselves and set up a few variables' @) E, m( j( q- p
setup-patches' L; c; Q0 c, k
make-current one-of intersections
& E+ N' e2 n$ s0 a. \4 S label-current
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0 X; h2 z: D& a* |# O& r set-default-shape turtles "car"
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# @& R: i3 @. ^0 [& R G# w if (num-cars > count roads)6 b' D: c& D/ g7 | O% i
[
1 I( @, A" f+ ~6 P user-message (word "There are too many cars for the amount of "
0 r5 q: o) T& O7 j2 j "road. Either increase the amount of roads "
3 T0 q9 L& P; t# I' g9 f& D "by increasing the GRID-SIZE-X or "
9 g: i! K U' c( V T/ d "GRID-SIZE-Y sliders, or decrease the "3 T3 V4 \: v$ {( o! i8 o( Q8 Q
"number of cars by lowering the NUMBER slider.\n"
9 q' O- @. {# _8 o5 G' A" ? "The setup has stopped.")( _) a! j* ^- e; N* E
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color: `1 Q$ ` u) ?: p6 x
crt num-cars6 F; A% M1 e* \% x9 \ o9 U
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setup-cars
/ P7 t5 }! }) e0 ~4 S- S& w0 k set-car-color0 x1 N: t! ]( r7 W
record-data. e0 g! C" ~, Z" o% ~
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;; give the turtles an initial speed
0 m2 S2 b0 J% u' ?# B- o ask turtles [ set-car-speed ]
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) V3 I$ A6 z# S6 ]5 I0 N/ l reset-ticks" H& A+ @4 ?( b9 C& z
end' D+ Y, t; l* Y9 v w: f
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;; Initialize the global variables to appropriate values k: x) L% M" R7 D
to setup-globals
( _% ~9 A1 m$ T) _& R7 K5 W set current-light nobody ;; just for now, since there are no lights yet
* F0 R) W, w7 s set phase 0 k% y2 u# L8 Y0 k
set num-cars-stopped 0* p6 l! l2 s+ B
set grid-x-inc world-width / grid-size-x8 M6 |8 Q) [8 _5 N" ~
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
: y1 h4 x7 y9 A: g- B set acceleration 0.099
1 z1 ?8 A2 W! H1 Uend
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, Z2 k+ l& E" b, M! T3 V;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
" M Z5 q, n/ Q9 c% b;; and initialize the traffic lights to one setting; V- Q& N9 g5 Z) E0 i" W1 e
to setup-patches
3 X, {5 G" W' p ;; initialize the patch-owned variables and color the patches to a base-color
2 n7 E& u+ _+ a- L4 W. V9 { ask patches% `: T& p+ `6 f3 K$ ~; L. T
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set intersection? false
' ?& ?+ W2 c' J( D9 N) X( k set auto? false
' K4 J2 r" W$ @3 z! o7 J set green-light-up? true
7 A/ b; m; R6 s set my-row -1
" N' s( Q9 J' b) } set my-column -1
' C. F! I7 f, m$ x set my-phase -1* ^: D, t* `" D
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
# D: N4 X+ M; h, S# M" n set roads patches with
! a" k0 C& |& C4 d [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 I! ] h2 b* f (floor((pycor + max-pycor) mod grid-y-inc) = 0)]( t- D7 Z0 ^( N3 W& D- y
set intersections roads with& f# s. t* ~) C& |* s: {+ S( r0 W
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and- f6 Z: A$ u$ P0 L8 _
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
. [% R. k( Y3 ]) | S( L$ x6 ` setup-intersections
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5 j9 v' [7 p% F+ b7 P+ l其中定义道路的句子,如下所示,是什么意思啊?/ W1 D/ S! h0 a
set roads patches with
* s2 m \) _0 X [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or9 ] A. i$ r9 M. |' C% S+ a
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]" f9 c+ L/ N8 ]& M8 b
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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