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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。- J7 n" X* {! r4 i! u
netlogo自带的social science--traffic grid这一例子当中,; l" K, S' s; o0 ?
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
; x$ C: @" h1 `. p6 p grid-y-inc ;; the amount of patches in between two roads in the y direction7 Q, h0 w+ W6 M9 A. P
acceleration ;; the constant that controls how much a car speeds up or slows down by if
+ L" U& g& O( V. R ;; it is to accelerate or decelerate4 r) r0 n3 i8 _) u3 f: @
phase ;; keeps track of the phase2 g, U1 z% h/ E# o
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure8 e8 i) O I: L& {1 ^
current-light ;; the currently selected light
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! c& e* l* K0 {! n3 y: q ;; patch agentsets
3 J5 u5 e" _; I8 a& H intersections ;; agentset containing the patches that are intersections) h3 n% p/ J3 F2 c3 b; k) \
roads ;; agentset containing the patches that are roads
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$ E8 ]; o4 g$ c) v7 Cturtles-own6 p: J- X5 ]+ w% s
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speed ;; the speed of the turtle7 ^- U* W' L% p; y0 {
up-car? ;; true if the turtle moves downwards and false if it moves to the right
+ }% v" c7 z$ j5 I wait-time ;; the amount of time since the last time a turtle has moved0 S K* U" h- S1 k( {0 \
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads6 n$ {. U9 M5 T7 P/ d
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
6 I7 ^' ^9 [% ?4 D$ b7 j. ` ;; false for a non-intersection patches.
. y) y, m, U+ E" B my-row ;; the row of the intersection counting from the upper left corner of the, X5 s" Z9 J; O0 C9 `1 t! _2 ~1 n
;; world. -1 for non-intersection patches.6 v) E. r% f' r* d
my-column ;; the column of the intersection counting from the upper left corner of the) \* R! G' [4 R6 ?
;; world. -1 for non-intersection patches.
4 T5 h3 d5 o, g" y, \ my-phase ;; the phase for the intersection. -1 for non-intersection patches.
, T" K } T8 ]9 q' B& d auto? ;; whether or not this intersection will switch automatically.: |4 m. k! q0 A+ F* C
;; false for non-intersection patches.: m* W9 ~# X2 v+ w% e# I+ \
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* H1 b4 o% B9 k;;;;;;;;;;;;;;;;;;;;;;/ d' y4 z1 k. ~7 t( T3 Y& N; G6 q
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.- ^. o# Z# k# J# K5 ]& i7 u
;; Create num-cars of turtles if there are enough road patches for one turtle to
1 G+ E2 C$ f( Q6 V/ x( d0 x( G0 T;; be created per road patch. Set up the plots./ ]1 V8 D, Y6 ^' @
to setup& T# U5 a1 X0 B
ca
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;; First we ask the patches to draw themselves and set up a few variables
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make-current one-of intersections% ]& y: g$ E8 i3 `3 K
label-current
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set-default-shape turtles "car"
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' s1 e; L) W; s& t t4 k4 i- b8 b if (num-cars > count roads)+ Z2 y5 K9 a; H; s2 N
[
3 X( j7 l" z/ F4 o' J( w user-message (word "There are too many cars for the amount of "
9 r, a" K6 p; A/ G( k "road. Either increase the amount of roads "
/ B7 l, ]1 G8 h$ m) b. H "by increasing the GRID-SIZE-X or ": Z, b! z* {% X& X- w7 C: P% o
"GRID-SIZE-Y sliders, or decrease the "
0 @$ ~: p# K) `2 { "number of cars by lowering the NUMBER slider.\n"5 E6 M d6 |1 a, b$ b6 N5 V. G
"The setup has stopped.")
% H1 j- {' Q- b: N5 S stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color6 c* g& I5 K- h- v" P/ i' G% N
crt num-cars
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setup-cars$ c" T5 A1 X% L1 F% ?
set-car-color h/ a3 T. {, h8 L6 S
record-data
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;; give the turtles an initial speed/ C2 V B# B& |( E" P5 @4 y$ V
ask turtles [ set-car-speed ]. ^- @1 m5 o% C+ \( l! l
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reset-ticks6 m! ~# p9 l( `# B) C$ \. u8 h
end
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; c# U& I3 C s' E4 v; [;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet! `. s! B' w& {5 H
set phase 0
. t% h; [$ \3 x' E/ a set num-cars-stopped 0
# z4 ]) d+ B; C7 ~ set grid-x-inc world-width / grid-size-x
& x/ X$ a0 i9 U2 }; W* O! u set grid-y-inc world-height / grid-size-y7 q6 L3 f- n2 \! {/ G
$ I4 X! ]: r& @& G% g$ r8 u9 X, Q ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary: W' z# W$ g4 D4 @4 f% s
set acceleration 0.099! q M+ N1 x- k3 j7 y! t
end4 p" g7 C' l0 K" a, Z V
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,% Q" \- R* {2 m9 p! _0 R
;; and initialize the traffic lights to one setting
- v1 u! C; W0 {$ z1 @3 o5 Kto setup-patches1 Z- I' L6 U: V* @
;; initialize the patch-owned variables and color the patches to a base-color
# R9 u; @, l C9 c" J2 ~ ask patches
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) X: {, Q- i8 \' h. O" n8 ^( ^ set intersection? false
3 E/ \* B" P- u- z& A% @8 d set auto? false
7 k6 K0 t' X: X+ i6 { set green-light-up? true
$ |9 m% L3 ~" z set my-row -1
3 c1 G% w3 ~" @1 M+ ^ W. j g set my-column -16 q0 F6 r: E2 r0 L2 w; r
set my-phase -1
( ^9 ?! a0 L0 ~/ @% \' Q set pcolor brown + 3. l. [2 U$ f9 f; G" e" N
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% {1 T* q: o+ T. q1 c3 f ;; initialize the global variables that hold patch agentsets. o. i* R' L1 P7 s' z& a# v
set roads patches with! l; a$ n; Y4 V3 ^6 V8 G
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
) z& i8 X/ Z# Q! g (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 U7 }& ?% h) b' u/ m* m9 z9 K set intersections roads with
6 l% h% F( v( U7 @: P' h l [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and8 ^" k m$ }! |' g4 L* E
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 R0 a v) s9 d/ D8 d) n1 h4 d
! n6 W* L& t, [8 H4 T. R: W6 \) x ask roads [ set pcolor white ]4 b8 ?- Z0 F& h8 }) |' q) F" p; r& R
setup-intersections# ~; q6 p R9 Y/ Z. {
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其中定义道路的句子,如下所示,是什么意思啊?: l: u3 K1 o" Q, W
set roads patches with1 T9 l h, A$ l' x' l. a/ E
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or3 k e. `, O- u
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 c& J+ G- d2 \# K' ]
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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