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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。
+ l8 l6 R. j# X, jnetlogo自带的social science--traffic grid这一例子当中,
3 \0 h5 P5 E8 K6 L8 A* @globals
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* M/ [/ C! u5 B& x. T# A8 l# i% V grid-x-inc ;; the amount of patches in between two roads in the x direction1 Y0 ~; f5 G, s, }, }! [" W# X
grid-y-inc ;; the amount of patches in between two roads in the y direction
4 y/ k, O/ {# x, G/ J7 p acceleration ;; the constant that controls how much a car speeds up or slows down by if
0 K. g x0 M; R2 _! C6 M% o- l ;; it is to accelerate or decelerate
5 X6 w; n x: h0 `7 l phase ;; keeps track of the phase) `9 h( o9 X4 f/ @7 w
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
) P2 u% X Y: P) X/ A6 ]1 Q current-light ;; the currently selected light
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;; patch agentsets9 h7 x) f/ Z; w& I/ a3 r/ p& I
intersections ;; agentset containing the patches that are intersections' I1 u, F3 h- O \7 ~6 J
roads ;; agentset containing the patches that are roads
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$ `/ L2 Z% y6 t1 h0 m: h; rturtles-own
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speed ;; the speed of the turtle
6 I1 b! J \$ f# @/ F) E4 g: y up-car? ;; true if the turtle moves downwards and false if it moves to the right
* M% B W8 d4 t+ n wait-time ;; the amount of time since the last time a turtle has moved
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/ |: o: X" M/ _6 i+ S" z8 X. Zpatches-own4 \& i3 o8 y' U' b
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intersection? ;; true if the patch is at the intersection of two roads
4 W5 z p- w1 s# g; O5 G green-light-up? ;; true if the green light is above the intersection. otherwise, false.
" W% s1 U5 H( @" @ ;; false for a non-intersection patches.
+ y$ g1 {5 h/ h# R0 Y$ v my-row ;; the row of the intersection counting from the upper left corner of the
$ s! y+ f: D$ I: ]# | ;; world. -1 for non-intersection patches.
$ s* Y- M) s6 v9 V8 J9 ? my-column ;; the column of the intersection counting from the upper left corner of the4 }; ~ Y# h2 J" O' e
;; world. -1 for non-intersection patches.
! y+ V. Q5 F5 p$ Y& d8 v my-phase ;; the phase for the intersection. -1 for non-intersection patches.
- J+ M5 U% l# {( \8 \! c6 C/ i4 K auto? ;; whether or not this intersection will switch automatically.
* \% R, ] L" v9 b7 B1 a3 w, _$ A" X ;; false for non-intersection patches.6 }# p9 y6 l3 z9 {8 G
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;;;;;;;;;;;;;;;;;;;;;;
/ c: A5 [6 Y7 ]) \' v' ~& D1 O1 A;; Setup Procedures ;;
! M! d1 A# l3 c" q" ~3 Q- @# W1 A;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
1 D; a5 u9 K& d0 O/ @;; Create num-cars of turtles if there are enough road patches for one turtle to
' Y" ^# w$ |) T! l;; be created per road patch. Set up the plots.9 t# X% H q( `3 O7 T
to setup
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setup-globals- O% E; P' j$ s8 j e6 o
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;; First we ask the patches to draw themselves and set up a few variables* w2 y8 S+ R- d8 E
setup-patches7 \! `7 M3 l6 V
make-current one-of intersections
8 i: A6 x% w) ? label-current- q' a, b" i& e3 p. s. Z
4 w" P) C% r5 T6 w7 q set-default-shape turtles "car"
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if (num-cars > count roads)
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+ M; `* y# F. |# x, ~ J user-message (word "There are too many cars for the amount of "
4 M o, [$ Y, u) v, f) M* l, ~; D* R9 Z "road. Either increase the amount of roads "
G+ I* D0 m, u4 x4 [0 N; Q "by increasing the GRID-SIZE-X or "
2 w m8 } z0 h7 g/ ~& m "GRID-SIZE-Y sliders, or decrease the "
& {+ P6 \- y; @+ T8 j$ y "number of cars by lowering the NUMBER slider.\n"
4 S/ D" I5 g: ?: @" a "The setup has stopped.")
. D8 q6 p! N6 ^6 E stop
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4 U5 K3 e, [# G- N5 D9 ?) U: Z! N' m ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
2 g) U* y, w) ] crt num-cars
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& E( x9 N' c/ s* s setup-cars2 u: G5 H4 v8 c/ C- x
set-car-color
& n/ Z8 A' \. t! u8 L, | record-data
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3 j# d {. }, L ;; give the turtles an initial speed
# \. r$ C# D4 H9 ]& o$ J ask turtles [ set-car-speed ]6 m. z# Z: G" R6 @" E9 D
0 t1 f( M4 k) |. E reset-ticks0 r: B2 {5 N/ \4 v; {9 M
end
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: t! l% G! _3 I. V; y5 u;; Initialize the global variables to appropriate values9 H" B# M0 g4 `! ]! m
to setup-globals
* |3 c8 r5 L; b9 y/ R( d set current-light nobody ;; just for now, since there are no lights yet
. f* T& ~9 W3 l9 i4 x- Q set phase 04 U B) j% L4 z9 p* r) @' e2 K
set num-cars-stopped 0+ i- h4 k; ?5 b" k
set grid-x-inc world-width / grid-size-x
" n7 p7 Z+ Z1 O; b; I1 l set grid-y-inc world-height / grid-size-y9 B0 G$ _8 @1 i6 z4 n0 |
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary. ~- c, H, |% m, Y2 ]2 R: }
set acceleration 0.099
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8 r0 m) X2 j: Z: ^2 p6 T/ l;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
* ^6 c1 M1 h; G;; and initialize the traffic lights to one setting/ y! |1 Q: {. P& i* y; @
to setup-patches
3 E8 U! E& W& b1 Q2 d ;; initialize the patch-owned variables and color the patches to a base-color% W7 x9 E4 H _! _' }% ^6 s8 m
ask patches
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set intersection? false7 h" s: O1 G e
set auto? false1 J' l3 C& E6 u. S0 v3 W
set green-light-up? true
$ A+ d& \8 i2 w set my-row -1. G' i: p- g( ~
set my-column -1- D* g7 P; H) [6 U
set my-phase -13 i" o+ O/ G) Q2 N `, A' D
set pcolor brown + 3- o9 L% F0 P! p6 s$ M. E4 e
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;; initialize the global variables that hold patch agentsets1 x. P5 B: d" U
set roads patches with, m7 ^$ D7 J) I) m
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' p0 C5 g$ E6 i) X. P- J (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 L3 O' D5 |$ `! M6 P( s! O) t
set intersections roads with
1 }" ^( _7 ~- _1 r$ Q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
' e x+ L1 z' {& ^% A. V0 N (floor((pycor + max-pycor) mod grid-y-inc) = 0)]( H9 G& q5 ^0 x( R- o% g4 s, |
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ask roads [ set pcolor white ]7 C, I& u( K8 {5 |5 y) L9 w Z8 A
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?
f( |; z1 @, {: l/ |3 r3 z set roads patches with1 W+ C# |; J& h1 @; c# l" S
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or: s9 j9 x$ h) }9 @1 J
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 x f- ]! x5 P; g6 C( j) N; I* Q
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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