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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。- y; e8 D5 ]6 t- k
netlogo自带的social science--traffic grid这一例子当中,
k/ q8 f% B+ Cglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction! R* K3 Z4 N1 a4 i0 x
grid-y-inc ;; the amount of patches in between two roads in the y direction
0 M2 c* C1 w( g& Z# H acceleration ;; the constant that controls how much a car speeds up or slows down by if
* D v0 [& V H. `: N0 v% [ ;; it is to accelerate or decelerate
& {- ]! {6 s; V9 K% F phase ;; keeps track of the phase+ v4 o& q! M, t$ q
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure) \! v0 S* C6 U' v" I
current-light ;; the currently selected light. r$ T" k4 p5 T, ]& w* S
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;; patch agentsets
% x4 O3 z! L6 q; o7 p, v intersections ;; agentset containing the patches that are intersections
; \, G- ?/ p) f roads ;; agentset containing the patches that are roads; E) b- k- C1 P: B. J' P/ Q0 w( E
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turtles-own! s5 Q' T3 _2 R4 D. h( H* ~
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speed ;; the speed of the turtle
5 y+ v# S% n0 n& H6 \ up-car? ;; true if the turtle moves downwards and false if it moves to the right
0 w( c1 w$ j' C8 V7 s wait-time ;; the amount of time since the last time a turtle has moved# z' a! e! n6 A8 c) g* g
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( I6 `/ z! l; ?: P+ o/ bpatches-own
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+ v7 V* E- B9 o5 y3 i( `5 Q intersection? ;; true if the patch is at the intersection of two roads& @" y) K( w) v: L, C
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
- m i' g# P3 U ;; false for a non-intersection patches.
+ H6 O6 f$ S: q6 S& E1 b my-row ;; the row of the intersection counting from the upper left corner of the2 {4 h5 N, f! y9 R5 g+ x( z( \
;; world. -1 for non-intersection patches./ `4 X6 y9 V* m( I S8 ?8 U( P
my-column ;; the column of the intersection counting from the upper left corner of the
; q% y5 T% F7 ]7 Q" M ;; world. -1 for non-intersection patches.
e- ~7 ^9 v) \, N my-phase ;; the phase for the intersection. -1 for non-intersection patches.
3 |9 R% Q8 }% \: I$ N1 `- |! h( ~ auto? ;; whether or not this intersection will switch automatically.' o4 x& g8 N! i% E
;; false for non-intersection patches. q" c; q" D2 m8 r/ K7 m" q
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;;;;;;;;;;;;;;;;;;;;;;3 E$ L6 |# F; d' t/ i8 @0 Y1 e. `$ E
;; Setup Procedures ;;
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* M8 N" `1 g2 f; b( D: k;; Initialize the display by giving the global and patch variables initial values.
. A" \; g( J7 l# z;; Create num-cars of turtles if there are enough road patches for one turtle to: J# e) C1 I! H$ K! h, B! a8 o
;; be created per road patch. Set up the plots.0 q, h1 @" d. A; @- B
to setup q3 T5 B' p$ S6 x1 n+ ~* ` n
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables# s$ i( ]; N' g8 U, @; P) W
setup-patches) T7 O Y T, L+ H6 Z: R2 L6 f
make-current one-of intersections, l4 ^* W+ m) v1 c6 s8 O, b
label-current# A5 l# q5 B2 J4 U
& p; V( W D! J* N% U set-default-shape turtles "car"
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if (num-cars > count roads)
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+ V8 H! n3 k: L }6 U& j! d user-message (word "There are too many cars for the amount of "
" S; l3 `! [( ^" J; F1 J "road. Either increase the amount of roads "8 v: Q7 y) w1 L
"by increasing the GRID-SIZE-X or "' l" }) m9 k$ o1 q) r9 G
"GRID-SIZE-Y sliders, or decrease the "
/ N$ h t8 g3 R6 a/ P' U "number of cars by lowering the NUMBER slider.\n". M& Y& J6 G n+ i
"The setup has stopped.")6 }6 V6 M1 T1 y# p' o
stop) ?( M. b. w$ s9 v
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. c' g2 E4 B6 g2 u1 ? ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color# J( R2 { c* \- B. @. ]
crt num-cars
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setup-cars) x/ i! z. f4 Q0 G
set-car-color) @$ @- n: W4 k2 F4 T
record-data
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( N: Q. M. } ^- E. A- K ;; give the turtles an initial speed; ^ u. J; @ @$ k W5 `( U: [- p
ask turtles [ set-car-speed ]4 p: t2 X3 }: E! l" c1 {
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reset-ticks
5 P7 K' a& s! uend, m3 N: C; U& f' Q" X% L
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;; Initialize the global variables to appropriate values% B+ D6 i/ i: Q }1 C" R5 S
to setup-globals. z Y0 |4 C6 x; G- n
set current-light nobody ;; just for now, since there are no lights yet
( ^8 A+ i9 Y6 U" ? set phase 0) _4 V0 {( O {0 T. Q- W
set num-cars-stopped 0- K7 t( M6 Y5 y) J- G9 _
set grid-x-inc world-width / grid-size-x( l1 r& r2 i* ]) A W, ?
set grid-y-inc world-height / grid-size-y7 c( i" r: X" U& P5 y7 C$ ?
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
# M/ m/ E! q5 p2 ]/ h* ~! y4 d set acceleration 0.099
6 s* K, f' T: N* {end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,% E& }# m( _+ b' K \
;; and initialize the traffic lights to one setting
1 p$ p" ?! C- H0 G$ K8 Nto setup-patches
- U. |* z) ~8 _; P* d( W ;; initialize the patch-owned variables and color the patches to a base-color, B* y+ k( z7 [! R8 x( X
ask patches5 R* l8 U4 C4 F5 `& m% V! F
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! e1 i' S- c9 r) f7 t% j set intersection? false* I9 R% w6 v3 c f
set auto? false: @$ F0 Y ]8 z0 q! T
set green-light-up? true% ]1 j1 @9 X# d( i
set my-row -1
$ A5 T4 w' c% d9 C5 m* x8 \. X ] set my-column -1
, D2 u9 c; D8 j. W- a n3 u set my-phase -12 Q9 T" T3 n6 T
set pcolor brown + 33 W1 E6 h& Z/ j/ r5 x7 h
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) X0 o$ z4 ^; l ;; initialize the global variables that hold patch agentsets9 u0 p. F6 m' Z' F# w3 b' N
set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% E8 s: Z1 j: T# b+ s set intersections roads with% g8 U2 i) i$ U$ c* R5 j8 c
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
) _: i7 F1 q* o- i1 \& f7 s( K (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: I0 R9 Y0 V" u& U% Q3 t# m- `: s
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ask roads [ set pcolor white ]
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end' @! v9 t% k7 z, m7 m
其中定义道路的句子,如下所示,是什么意思啊?' ], q) H7 R/ D3 p$ i& ^- q. }
set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
- A4 ^+ ?+ m" N' ]. g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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