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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。& ~* o" k6 A' J* K2 ]# V
netlogo自带的social science--traffic grid这一例子当中,6 I$ k& o4 v+ I! [" ?8 u# v
globals, b" X# ~+ q" c0 K" R
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+ `0 M# m% ?8 a( {( x0 h grid-x-inc ;; the amount of patches in between two roads in the x direction
+ {; y& p* ~3 t7 X* v! v; l grid-y-inc ;; the amount of patches in between two roads in the y direction" P: q# U1 v+ W- m4 F
acceleration ;; the constant that controls how much a car speeds up or slows down by if
- z! A& y0 b: s ;; it is to accelerate or decelerate/ s2 V' E8 d1 t* C: c- t% U
phase ;; keeps track of the phase5 `" N4 Q& D6 V( s
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
! f+ a! ^( m0 ~# t3 y" e0 x% d current-light ;; the currently selected light
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;; patch agentsets1 S0 w1 L$ }* Z3 F
intersections ;; agentset containing the patches that are intersections
" f1 V% j# g& _; Y roads ;; agentset containing the patches that are roads/ @9 J, Q2 a4 w! M% m$ j
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' o4 ]) Q+ f0 Q& v8 U0 m9 J8 Nturtles-own
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7 |8 {/ S; y3 g( ? speed ;; the speed of the turtle
$ \1 w o/ l7 w$ r up-car? ;; true if the turtle moves downwards and false if it moves to the right5 e. b- n* b3 F: f3 l# u
wait-time ;; the amount of time since the last time a turtle has moved/ c& Q: @; O* K) U6 `
]
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patches-own, d2 o: G+ T; E/ P
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intersection? ;; true if the patch is at the intersection of two roads8 ^* S& F1 K3 r+ |+ X* A
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! M% d+ v- j5 h8 f# R) A( \3 z ;; false for a non-intersection patches.
3 }, J7 [* z" I+ ~ my-row ;; the row of the intersection counting from the upper left corner of the
3 S8 J" o" n2 y* y+ v; o ;; world. -1 for non-intersection patches.! [1 T( F) J4 v; {7 K3 R- b
my-column ;; the column of the intersection counting from the upper left corner of the6 l- u& c4 y6 @6 r
;; world. -1 for non-intersection patches.
6 }" O4 R0 @6 ^ s my-phase ;; the phase for the intersection. -1 for non-intersection patches.
2 s0 i( k6 B; {0 p* U auto? ;; whether or not this intersection will switch automatically.
& y# |( y3 D/ `/ F, ~" R5 M ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;9 H- E+ j" e3 j4 J" [2 D
;; Setup Procedures ;;/ b1 q4 |8 J2 \. _2 |( [7 J; [
;;;;;;;;;;;;;;;;;;;;;;
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$ V: q+ C/ e% Q' \, C;; Initialize the display by giving the global and patch variables initial values.
9 l5 X$ q) e) q. E;; Create num-cars of turtles if there are enough road patches for one turtle to6 N8 ?3 U" u5 e8 D
;; be created per road patch. Set up the plots.- j: `- g$ [+ P) I5 w3 ]* Z3 W
to setup
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: a. e- T/ X7 h( }4 [5 B0 E setup-globals' ]" ~9 Q& Y# Q4 O
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;; First we ask the patches to draw themselves and set up a few variables9 o, K8 y# C8 O, v$ B
setup-patches
& f% W# z' P! m+ ^ make-current one-of intersections% a" |1 V# M! {" J* @
label-current) g5 p, b/ r) o
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set-default-shape turtles "car") y$ l, b& V2 u9 P1 m* h
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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 "7 Q. e; |, m* d& N& P: ^: }! o. f
"road. Either increase the amount of roads "
+ o' S" Z X. d' A4 n$ {/ o "by increasing the GRID-SIZE-X or "
: k: j' w' q# c E "GRID-SIZE-Y sliders, or decrease the "6 A+ E; `8 R5 K5 B
"number of cars by lowering the NUMBER slider.\n"
; Q N. [/ w% m' o "The setup has stopped.")2 J- Q; o1 B- e* T# S
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
x; I9 N+ [) a& F/ `/ j0 F crt num-cars/ v; T) X* k$ i+ v$ [# z
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setup-cars
: I" Y4 f2 Q5 |7 ~ set-car-color4 e; U, K5 l% h b0 _1 D, i
record-data
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;; give the turtles an initial speed
, x1 l9 F# N) G; x: I ask turtles [ set-car-speed ]( }7 z; W, ~3 R
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reset-ticks
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;; Initialize the global variables to appropriate values
3 t! r" y5 p/ |, Zto setup-globals1 l l+ \$ M$ ^3 _3 `3 U
set current-light nobody ;; just for now, since there are no lights yet4 A% s5 t# {7 k' z1 e6 n
set phase 0
: D: v! i1 Q' g$ h# J4 U% y set num-cars-stopped 0
/ r) J% ^8 C9 Z7 L- `: w set grid-x-inc world-width / grid-size-x8 K1 j( u, R& i' I, d
set grid-y-inc world-height / grid-size-y* f9 a) p1 S% Q
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
/ @6 n0 G! z7 Y" ]6 k set acceleration 0.099$ {; i3 } K. `2 |
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
+ X) F4 K8 U" _+ M- u) e;; and initialize the traffic lights to one setting
* V1 j2 q9 c# E$ @& ]" Gto setup-patches
: Q1 P1 [; ]% u" _ ;; initialize the patch-owned variables and color the patches to a base-color
) k' T$ M! T5 ^( G/ H* Y' G ask patches ^6 g6 N1 ]$ Y9 C
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set intersection? false
/ I. a8 E$ M# x! M2 C set auto? false
+ e4 U$ N$ D* ~4 {1 Y( C2 \/ M; \ set green-light-up? true0 ?1 @: g& w7 e$ T. L
set my-row -1
3 x; b7 l/ y/ O( @+ [ set my-column -1+ P$ |' i# G; Q, e$ z
set my-phase -1
4 J# ]; o. N } set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
+ w, m- N: i/ _# W, i# T; N set roads patches with
% @" f0 \/ u0 [9 L" u: A) W1 ^ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, u3 f* \+ `, `; ?1 r( }* k
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
& d2 ~- z. Y9 }! J. p$ t- u9 C% C set intersections roads with3 A# j* l3 D8 ?- W [" n
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and: Z7 @0 d! z+ z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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: A$ Q* s2 G5 o/ a# H B! R! ` ask roads [ set pcolor white ]* w8 w/ x( D$ }! l
setup-intersections
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0 V. {+ K4 q' l其中定义道路的句子,如下所示,是什么意思啊?
" u2 I. N3 \, j7 x( s: t set roads patches with: H; z4 S2 ~" d2 z! C* W
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or* ^9 X0 A! @$ E
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 M' H) G. [! M/ a& v& M8 S [* R3 u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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