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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。' Z7 G% Q8 S' b4 e5 z* m; k
netlogo自带的social science--traffic grid这一例子当中,# k T* x1 m o
globals
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# m7 C3 U! c0 J. a2 Z, T. ~4 K grid-x-inc ;; the amount of patches in between two roads in the x direction
. T/ g( h/ y1 K grid-y-inc ;; the amount of patches in between two roads in the y direction
# O0 u+ |9 V% \9 ~$ i acceleration ;; the constant that controls how much a car speeds up or slows down by if
4 F- Y4 M; }* U( } ;; it is to accelerate or decelerate" h# G, j" c- \( J$ g
phase ;; keeps track of the phase5 k) S U1 l& u1 ?" N$ A' e
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure7 K4 P7 g2 y, P1 x
current-light ;; the currently selected light c8 E6 v, e$ A @/ N5 }; i( k
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;; patch agentsets
3 K1 D" D" ^+ s, ]7 m f, i intersections ;; agentset containing the patches that are intersections
' n* u; D0 H, a$ V3 U/ d roads ;; agentset containing the patches that are roads
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1 }0 N0 i: d$ e& V$ }9 e8 vturtles-own
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! D( e# [0 X( ^( \ speed ;; the speed of the turtle
8 D8 H8 y4 B% G+ d up-car? ;; true if the turtle moves downwards and false if it moves to the right
: c6 S4 ?+ X" S0 N# } wait-time ;; the amount of time since the last time a turtle has moved2 ~' ?8 h5 w: |+ d. W
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" Z3 v- ^3 d) \! ^patches-own# w7 V- e. i, l
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intersection? ;; true if the patch is at the intersection of two roads6 o( \/ X- b) Z' k. S9 x! \: s# Z! |
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
7 l% X# G( Z# s* _ ;; false for a non-intersection patches.
2 n, g& d& P2 P4 f! I5 d2 x( M my-row ;; the row of the intersection counting from the upper left corner of the5 q$ ]9 z: N8 g7 v& ]+ T
;; world. -1 for non-intersection patches.2 [+ q% q Z. d/ Z) v
my-column ;; the column of the intersection counting from the upper left corner of the
8 u' G' P5 X( H ;; world. -1 for non-intersection patches.
' \6 S/ u9 m. g: r: b) Y0 J my-phase ;; the phase for the intersection. -1 for non-intersection patches.0 G0 D! X# {# i( x* Y; x
auto? ;; whether or not this intersection will switch automatically.! K( H9 N' S& ^9 N9 ?5 N
;; false for non-intersection patches.9 K" n* \. w: J% ~8 y# Z
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* w, U- O+ G$ T2 |% b;;;;;;;;;;;;;;;;;;;;;; T6 r1 k- {: c2 V
;; Setup Procedures ;;
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$ O* Y; H% F, A6 W# [;; Initialize the display by giving the global and patch variables initial values.( N& _) D; w( l
;; Create num-cars of turtles if there are enough road patches for one turtle to. v6 F3 o3 G& l0 p9 {$ F5 ?
;; be created per road patch. Set up the plots.
Y! J7 t1 ^ @- @' oto 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
; n Z% f b* J2 t0 o% {9 k setup-patches: A; N0 F' L2 Y4 V. d
make-current one-of intersections
4 q- V4 Z& f9 |( J- E label-current* b% r+ [% q! D/ @9 Z4 H
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set-default-shape turtles "car". s% a# \) P2 D! h0 C3 o
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if (num-cars > count roads). r1 Z4 g7 c0 t; E3 x
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user-message (word "There are too many cars for the amount of "6 y* b* u) B) X; x
"road. Either increase the amount of roads "# Q4 l7 h% e: w7 v
"by increasing the GRID-SIZE-X or ". Y4 Z8 ~. B! ~9 r& r" J' [
"GRID-SIZE-Y sliders, or decrease the "
: j9 s$ i- O7 X "number of cars by lowering the NUMBER slider.\n"
* z. _% {! L) n7 x: I0 f "The setup has stopped.")
) f z* _8 I, H) L2 K) X* L stop
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, s6 t! s' G# M' t5 T ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color8 b$ f O' {( s* c% y9 j
crt num-cars5 O' L8 T; ^' ~+ p+ B2 f% y* Y1 a, c
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setup-cars. ]: o2 L4 k# n" {! k
set-car-color
1 M. Z1 s! r1 Y0 S( g3 U7 i record-data
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' w3 M/ J: z# I4 H* z, ?) p ;; give the turtles an initial speed3 F0 l3 a' [! V/ _) P% T# ^ N/ j, h
ask turtles [ set-car-speed ] n6 X s: ]8 y! X6 k
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reset-ticks
$ k( y) V2 J4 T3 B# L$ T6 R0 Yend
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; Q- \2 r6 Z5 Q) ^: a;; Initialize the global variables to appropriate values' V* [' Q7 o4 _ O+ j- Y
to setup-globals9 W, [& d' q; e7 i3 C$ ]& ]
set current-light nobody ;; just for now, since there are no lights yet, a) ^6 Q( r8 N+ i/ }- l, G: h
set phase 0& h6 f1 S1 B- G1 b
set num-cars-stopped 0
8 i$ d. t9 j# s- o! }: t set grid-x-inc world-width / grid-size-x
+ n+ O$ L2 f0 S set grid-y-inc world-height / grid-size-y4 O! `# F/ k7 a" s. j
; \$ L. n$ ~0 H) ^* I- u ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary, a7 ?+ d8 ?2 [# p
set acceleration 0.099' k5 ~! K. _$ M7 @
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
1 w. j5 d/ c- I( `! w# h& k;; and initialize the traffic lights to one setting
* T$ B$ L7 ?1 f) {; y0 Eto setup-patches" u) q0 z8 `# a/ c9 x/ n
;; initialize the patch-owned variables and color the patches to a base-color) [* t" t6 Q, f0 [4 O
ask patches% [& K& G' S& t2 u. m$ j5 [
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) z- G% C: {7 x set intersection? false- L7 x$ B9 o8 J1 `% `' `! i
set auto? false
3 k2 u7 f1 I9 w set green-light-up? true: M& _! H* S+ x; y3 q7 K
set my-row -1
/ {& G2 b J f1 c1 i. m set my-column -1
+ [) q) x7 v; u+ e- }' k8 U6 p3 K2 \ set my-phase -12 U# M9 N# S/ p- u
set pcolor brown + 3
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( n5 s3 D$ u1 R0 J2 V, [3 H A ;; initialize the global variables that hold patch agentsets0 P- v) L) v! x% |
set roads patches with
- v7 j2 Q- c0 s/ \* U) w* F [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# H6 k: p: _; M1 n+ p# s (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 `2 a9 c+ h2 D$ y set intersections roads with) N' u6 N/ F( Q" t) s: c. D* G' M
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and) d! M" M: i' W2 s" ~8 r1 |8 T! G
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 x( g4 W( q9 ~6 D/ Z
* ?- ~# ~/ r- J ask roads [ set pcolor white ]" R6 W7 g7 d6 v
setup-intersections$ ?4 J8 H4 @2 n$ `
end! ]* G( T. |3 p1 G, L' v
其中定义道路的句子,如下所示,是什么意思啊?! R2 e v+ p/ s! q _9 V" B
set roads patches with
9 W/ @- ], S5 s1 p) S [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
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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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