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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。- [( W& r3 x4 K2 z% k- P; l/ a Q& x
netlogo自带的social science--traffic grid这一例子当中,
$ c1 ?# Y4 e8 M: oglobals0 g, {2 a- h* Q) V
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grid-x-inc ;; the amount of patches in between two roads in the x direction
6 p7 Q' G$ Z/ J$ | v( o grid-y-inc ;; the amount of patches in between two roads in the y direction0 v6 q0 _; d6 f5 ~" h3 e) w
acceleration ;; the constant that controls how much a car speeds up or slows down by if
5 p" |$ V: X' ]7 U( K0 q. ]& B ;; it is to accelerate or decelerate$ V1 d! ^8 \! a# m* z* ?
phase ;; keeps track of the phase5 U2 U3 v3 C- ]4 U: @2 P6 U
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
, R4 n2 h- b8 r) d, d current-light ;; the currently selected light
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;; patch agentsets
6 Z+ h" Q" L( x% g1 l intersections ;; agentset containing the patches that are intersections9 Y" S) ?; i- r I
roads ;; agentset containing the patches that are roads
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4 }2 S* X% r3 S( x* \, _# \; ^turtles-own
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: n& j+ u: E' F u$ ^ speed ;; the speed of the turtle
9 i2 E4 | [2 ]* B, p s3 c up-car? ;; true if the turtle moves downwards and false if it moves to the right
. z5 Z" c- Y9 W* |1 @ [ wait-time ;; the amount of time since the last time a turtle has moved
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: ?. S& f8 g% b% y U+ ypatches-own
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3 _. ?7 @; f: x; C7 n intersection? ;; true if the patch is at the intersection of two roads
- M3 @2 j+ o/ Y green-light-up? ;; true if the green light is above the intersection. otherwise, false.
) r. T2 v- I& h ;; false for a non-intersection patches.; ?% d2 Y3 h2 l
my-row ;; the row of the intersection counting from the upper left corner of the
, g$ U3 a1 x( J ;; world. -1 for non-intersection patches.
% Q. r) e9 ^, Z( P6 k my-column ;; the column of the intersection counting from the upper left corner of the
! b% b' p5 ?7 n1 T8 l ;; world. -1 for non-intersection patches.
8 ^3 B. \, z9 h# [ my-phase ;; the phase for the intersection. -1 for non-intersection patches.
, G& }* U: ` p- ]# {) { auto? ;; whether or not this intersection will switch automatically.
( w3 g2 n# Y/ H ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;& T1 h5 J l ]% W4 |
;; Setup Procedures ;; j7 n) E6 A' B/ S. j
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
& Z/ Q& L) p+ ?;; Create num-cars of turtles if there are enough road patches for one turtle to
9 L# E9 ^9 d) B% z;; be created per road patch. Set up the plots.
r* p _1 x1 y3 Gto setup
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: i& G/ U( g3 e setup-globals0 T# q( E! c+ J! H/ g
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;; First we ask the patches to draw themselves and set up a few variables$ z4 i7 ~6 r" C. e: O# {
setup-patches2 t, q4 p. ?- e- ~ B8 B: `
make-current one-of intersections. T* F: N4 I4 R( a. l+ ^
label-current
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4 d/ e8 B& {. a2 i) y) V1 M set-default-shape turtles "car"& t* t( U- x3 [! p$ }
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if (num-cars > count roads)
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" X$ n0 h( r1 v K* P user-message (word "There are too many cars for the amount of "
; _# l3 Y2 {0 K" N9 A "road. Either increase the amount of roads "
6 S& ?+ T# J9 k/ r% L "by increasing the GRID-SIZE-X or "
. v' z- R5 Y$ T& K "GRID-SIZE-Y sliders, or decrease the "7 }, \; Y4 S) `, w. }& |
"number of cars by lowering the NUMBER slider.\n"
) o* J$ K7 m3 _; F: X+ ] "The setup has stopped.")
$ r: N5 l3 ?) ^% \3 h9 j) \ stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
) @- u& d7 F$ m8 X9 p1 n, S crt num-cars
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% ^2 D9 P) r9 ? setup-cars
: g/ O2 P) b7 R8 k% U7 ]! l set-car-color
$ k% `- d1 ~# ?2 x record-data
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;; give the turtles an initial speed% m( I, X ] [ M8 m( o7 o/ D- P1 h
ask turtles [ set-car-speed ]; m& u0 m+ V6 [: z" x J1 y. {# y" P: e
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reset-ticks
6 x/ q; X* T5 J0 ]end
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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 yet0 V \) Q- b5 s. p
set phase 0
# q" U: q+ n+ w5 U1 F set num-cars-stopped 04 E$ ^( M, b, b: b* L
set grid-x-inc world-width / grid-size-x9 g$ K% _ {+ X% L
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) u# Z+ o2 D7 P) v5 G# F
set acceleration 0.0996 _! E' s" `8 I$ y8 ]
end' T7 A+ g) {8 F2 l2 L* ?2 Z: L) B0 k
7 T7 Q% m! ]9 d( l& t: {;; Make the patches have appropriate colors, set up the roads and intersections agentsets,& r) s; y" u0 o8 `+ q: H- U
;; and initialize the traffic lights to one setting
- a! s& p) J! }6 K$ Dto setup-patches& t' A- A- M* |' K6 [
;; initialize the patch-owned variables and color the patches to a base-color1 S9 i" O5 Y# E& n) M
ask patches2 @ {; ?' E6 C* S3 Z6 P! I) @
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set intersection? false
0 t$ u& F5 n! { G0 r set auto? false" Q: o( } S# C/ l8 F
set green-light-up? true5 j! s1 l# @4 u3 `. V: G
set my-row -1# v$ ^% ^' h. O& U w$ b% F4 G
set my-column -19 y1 ^2 X) n/ J+ G
set my-phase -11 {+ ^7 k; p& b* V7 ^$ Y
set pcolor brown + 3
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1 y" x) B( O' m% h# b7 w: E- J ;; initialize the global variables that hold patch agentsets* I* T7 p6 t# C7 b. v
set roads patches with
" p" p9 J: E; M( r8 c [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or4 A: p6 p" K, ]/ n
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
H2 ~4 K% I% D* ?! ]9 ? set intersections roads with0 I$ N( `/ V2 n, J
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and9 H$ i$ Y: T& I/ B+ X g) J
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 i0 `* \5 Z# \* E5 y
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ask roads [ set pcolor white ]' f* \5 A8 M- P' N0 Y1 t6 N
setup-intersections% P! R( }+ e4 ?& b. G* G1 S
end8 e5 E$ W5 b" m) s
其中定义道路的句子,如下所示,是什么意思啊?+ Z, D$ L0 \. e5 w2 t7 t
set roads patches with
! z7 q1 H3 `! I+ W! z1 r! q6 K. W M [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or- J! }, w {: A6 i" P# y3 D {
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 p- w$ b0 h* f. f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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