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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。& F& ?' E4 b) D5 O5 k
netlogo自带的social science--traffic grid这一例子当中,( F- R9 E# v0 p z- b! D/ {% K
globals" v9 n$ l+ n: n( f
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grid-x-inc ;; the amount of patches in between two roads in the x direction
- `: W& E% S% X! e( s6 r# j; I5 ~ grid-y-inc ;; the amount of patches in between two roads in the y direction
% A- x; z) m! k acceleration ;; the constant that controls how much a car speeds up or slows down by if( [; d' G4 z! }( ~& m" u- V
;; it is to accelerate or decelerate
" \& V% V2 n4 a9 o1 s phase ;; keeps track of the phase
, ^; g2 r$ C8 z. ] num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure0 g5 X$ F F0 g
current-light ;; the currently selected light4 t+ T( c8 p W6 d
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;; patch agentsets
& Y, W$ @' O. ~. B7 C+ G, _1 V* ^, w intersections ;; agentset containing the patches that are intersections3 h& ^6 [- z1 h+ j. C3 z
roads ;; agentset containing the patches that are roads
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turtles-own
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' M: N) J" l' C( A; I+ p. } speed ;; the speed of the turtle3 q; N3 z& r# V% b! z, ?: a
up-car? ;; true if the turtle moves downwards and false if it moves to the right
+ H% F0 f* G: l wait-time ;; the amount of time since the last time a turtle has moved
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patches-own0 z, D! v" v- `1 v
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intersection? ;; true if the patch is at the intersection of two roads
6 q+ K# V) x. S4 ?+ B2 E green-light-up? ;; true if the green light is above the intersection. otherwise, false.
# h, W; }" a/ {7 B- r/ q* y% U' ? ;; false for a non-intersection patches.) T) o* g1 ~& Y2 S. H2 L
my-row ;; the row of the intersection counting from the upper left corner of the
( H2 Y' s* t0 \7 j3 w6 K R { ;; world. -1 for non-intersection patches.! U9 ~) M1 I5 M0 N* s
my-column ;; the column of the intersection counting from the upper left corner of the
1 ?0 A/ h7 L& R% C7 D N+ l( h- \ ;; world. -1 for non-intersection patches.
$ ^$ s; u, E% L my-phase ;; the phase for the intersection. -1 for non-intersection patches.
( ^# P0 ~9 y2 r5 q3 Y6 [1 ? auto? ;; whether or not this intersection will switch automatically.
6 @1 M6 b ^% h4 J. Z ;; false for non-intersection patches.
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2 ]7 Q. I Y/ q v3 A5 d1 l;;;;;;;;;;;;;;;;;;;;;;
z/ J( L7 d {, P7 h;; Setup Procedures ;;
U! `; g8 a: t' Q5 S0 O5 b;;;;;;;;;;;;;;;;;;;;;;
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a% b- ]; z# Z; \2 h0 }, _;; Initialize the display by giving the global and patch variables initial values.9 A- {9 H$ G9 E8 ~; Z9 X
;; Create num-cars of turtles if there are enough road patches for one turtle to
' V& A4 z' p6 s: z+ k;; be created per road patch. Set up the plots.# Y& f! }! j- g$ m
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& T0 @& H# `, r b) p
setup-patches
& z( \% p3 {3 O. ~) h/ x make-current one-of intersections- a" }' }+ T- o- q6 H2 q9 B; L
label-current
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set-default-shape turtles "car". h8 V3 ]' s/ x- ~, b
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
/ e% Y2 a- ?3 \7 I5 x2 `' E "road. Either increase the amount of roads "* F3 J1 z1 e7 w
"by increasing the GRID-SIZE-X or "0 e0 ^( M/ b3 V
"GRID-SIZE-Y sliders, or decrease the ", G0 Z; M! M c# ~" q4 d
"number of cars by lowering the NUMBER slider.\n"% M$ [! K- o. _# m2 N, B: q3 o, X
"The setup has stopped.")
* R/ e6 w( Z" V6 D stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
# V, [! p% q" z8 n5 f, v) o q e, l' K crt num-cars- Y7 Z- G% c% f7 w
[
" B! E5 F, ?) r9 j9 Y, a- P setup-cars
- F4 d" u$ J8 y4 Z! T set-car-color
; B1 S) Q. V! V record-data# e0 M6 f9 m8 Z3 E$ k
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;; give the turtles an initial speed" d% w+ M0 ~& U9 U
ask turtles [ set-car-speed ]1 f+ }2 [0 y9 l4 l0 ~1 N _
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reset-ticks( u7 G" @% v* G+ _. |2 [& h
end
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;; Initialize the global variables to appropriate values% W0 B' ]5 ^" H0 ]0 b3 U/ y0 Q
to setup-globals8 B3 D8 p5 E1 ]4 m
set current-light nobody ;; just for now, since there are no lights yet
" U1 U% o* b. n4 R: A set phase 0
" r* O0 x+ H# d+ I" g( t set num-cars-stopped 01 X" b* P0 e0 e
set grid-x-inc world-width / grid-size-x
9 O7 I8 v' z+ D& H! t+ @* q 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
2 Y) h( d8 X1 D3 M5 |' l; ^ set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
, \$ X$ }3 g3 t y6 L8 z5 q) {3 x, L;; and initialize the traffic lights to one setting. Y0 N5 y$ j6 i W! T' w, n3 v1 z
to setup-patches
. S6 a `' E8 d ;; initialize the patch-owned variables and color the patches to a base-color
& L$ @. G* y: W* F5 L( d7 ? ask patches
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set intersection? false6 y5 g% C7 w0 Z$ m9 B
set auto? false
5 B ~6 J# ^6 ^+ I* m4 }" ` set green-light-up? true
4 P! {, v6 ^# Z set my-row -16 A0 _4 F, ~ A& V0 }4 V/ |( [
set my-column -15 R: ^) c% h2 u' M
set my-phase -1; j, T5 v9 D* U% c A" [
set pcolor brown + 3# B$ B, z6 `7 a1 p8 D1 Y; B6 ^
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;; initialize the global variables that hold patch agentsets
# G4 g l1 Y% l4 i3 `# e set roads patches with
5 O! N% I4 f2 S! u' [ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 }: j7 Y: N( k (floor((pycor + max-pycor) mod grid-y-inc) = 0)]) v W2 I1 u# q6 ]8 O9 K
set intersections roads with6 ^! w5 n p+ B G
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and+ e8 H* l* k3 O5 h' g7 I
(floor((pycor + max-pycor) mod grid-y-inc) = 0)], F4 l: g6 U' F+ f6 t. }
& J: C, F4 D8 e- Y4 t ask roads [ set pcolor white ]7 i4 E; g- j# P5 o5 I; |& w0 W- V( V
setup-intersections B1 ~, a" g6 I G1 Z1 Y9 K, D; c
end
0 |4 n# I9 R. r9 q1 I其中定义道路的句子,如下所示,是什么意思啊?
; K8 l2 ^1 {% a& {3 S1 a: P/ c: t set roads patches with y8 u+ Q# C) A- A% l; p
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* k" \5 C! \8 T# T (floor((pycor + max-pycor) mod grid-y-inc) = 0)]) Z! I! p( Q$ c3 }4 |% u7 G) r
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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