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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。7 z# ^5 Z; R3 S6 C; U
netlogo自带的social science--traffic grid这一例子当中,3 F2 D2 z' |0 _; b2 W5 K4 q/ }
globals
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0 o" G9 ~% X) M/ e* {: G8 ? grid-x-inc ;; the amount of patches in between two roads in the x direction
5 z' K& k! [/ w# D grid-y-inc ;; the amount of patches in between two roads in the y direction
( A+ u9 _( ?3 k E acceleration ;; the constant that controls how much a car speeds up or slows down by if
0 \4 d/ n4 c8 @2 o; D5 n; ~9 C0 M; T ;; it is to accelerate or decelerate+ @2 \- f' Y$ { d' w, t
phase ;; keeps track of the phase* o1 d! P+ ?* [6 C" L/ h5 b p
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
0 O! n! ^3 t3 L- u) f current-light ;; the currently selected light9 P' C) J/ z# l2 D- ^7 g+ e
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;; patch agentsets5 s+ E. ]# g" ^% h
intersections ;; agentset containing the patches that are intersections/ a% {4 b1 k1 {+ `" v* T+ J, Z
roads ;; agentset containing the patches that are roads2 C1 S1 ~7 F$ g- q
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" _( x2 Z; M0 a8 Gturtles-own
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8 `& c: V3 ^9 _& {0 }; {' w1 u speed ;; the speed of the turtle
5 f( T. K- F3 t! R% A up-car? ;; true if the turtle moves downwards and false if it moves to the right
! b* P2 R- j; \% ` wait-time ;; the amount of time since the last time a turtle has moved/ R: L% v6 U( D4 ^4 z) J
]
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2 B2 n7 ^! C6 U' zpatches-own. ?0 T7 V( s7 E! H9 X: A8 ]2 z, A
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intersection? ;; true if the patch is at the intersection of two roads
/ }1 Z* k5 { }; L; I" I$ G; `* `0 w green-light-up? ;; true if the green light is above the intersection. otherwise, false.
. a& ?" ^; Y. H, P: Y ;; false for a non-intersection patches.
! k8 ] Z$ _! V: S! V$ f* O# D/ R my-row ;; the row of the intersection counting from the upper left corner of the, a2 s- V- z$ G$ M2 w9 S. B
;; world. -1 for non-intersection patches.4 L9 X0 @' n- i, s, }
my-column ;; the column of the intersection counting from the upper left corner of the
, k+ S+ C. Z7 S6 L6 Y# z7 H% [ ;; world. -1 for non-intersection patches.
- `9 l! o& o& k my-phase ;; the phase for the intersection. -1 for non-intersection patches.5 h! b( F0 [& a$ k0 Y8 ?- H# W
auto? ;; whether or not this intersection will switch automatically.
1 Y0 F) O/ m2 e) ~# R0 B. Q ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
, |; F0 V+ s- M5 N- C& i8 `6 R;; Setup Procedures ;;
6 C) r/ s: u! j;;;;;;;;;;;;;;;;;;;;;;
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$ A4 H- m/ J5 Y0 @; C( v8 W;; Initialize the display by giving the global and patch variables initial values.( @3 X: L- F2 X/ B+ o1 G6 [, }
;; Create num-cars of turtles if there are enough road patches for one turtle to7 w/ w8 Z7 @. X( K7 M" Z
;; be created per road patch. Set up the plots./ F. X5 t7 Y2 w g! }/ v
to setup7 ~: ]- j: a3 O, x& _" }$ S4 b l6 e
ca
1 c" l/ f4 q5 E setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
! W( w3 O% O1 [( y) @ setup-patches
1 G; X/ D+ f( O$ W, V make-current one-of intersections g# R: S. t+ u% U4 K2 V- y% T
label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)# Q- P, ]- w+ T" ]
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user-message (word "There are too many cars for the amount of "7 A ?: _' f+ H$ W4 O) b. }! c
"road. Either increase the amount of roads "
* l& C0 D6 p0 \' |/ q% r "by increasing the GRID-SIZE-X or "
' s$ I/ n1 q# |" T) i4 R% o8 g "GRID-SIZE-Y sliders, or decrease the "
8 F+ n X, C) @' S% M2 G. W "number of cars by lowering the NUMBER slider.\n"
4 B# |' B! P q1 X1 |# D% |7 c "The setup has stopped.")
0 ^3 N) r. S P( M+ s- k9 N; j stop
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" D7 m/ W! _+ u4 j ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
. T5 q% _& S# I' V/ P# d crt num-cars
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setup-cars
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. ~8 l' c$ |+ k3 J3 ` record-data
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& N/ J) G3 c R) G; F, N ;; give the turtles an initial speed
+ k/ u3 _5 m" t/ {& K ask turtles [ set-car-speed ]+ P6 v0 z; j$ r5 a
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reset-ticks) n6 y/ n9 Y: D, X T, S
end
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* v: Q% k$ }6 L% [) U! T6 @. @;; Initialize the global variables to appropriate values" U6 W, G5 ^4 L5 p! N# M
to setup-globals/ v0 i( m$ C: G6 Y, _3 ]7 h5 s
set current-light nobody ;; just for now, since there are no lights yet* g* K$ T- _; {$ ~+ Z
set phase 0
. V+ n8 z8 j, @4 i; E8 Y7 | set num-cars-stopped 0
' F/ E- X' Q1 [# {+ T set grid-x-inc world-width / grid-size-x# ]3 M( P) D, Q
set grid-y-inc world-height / grid-size-y
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+ F6 _6 N2 d k9 Q ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
# E; `8 ?: K' Z" Z4 q! ?4 Z set acceleration 0.099
) B2 R% s+ u" G: `* Eend
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; P1 ?. Z5 L# Y, p( z. D;; Make the patches have appropriate colors, set up the roads and intersections agentsets,# K1 O |' k$ p# f
;; and initialize the traffic lights to one setting
0 V' v9 h0 h; n3 l6 ?! ^4 Tto setup-patches
. P, y" i% b+ r5 ^7 h ;; initialize the patch-owned variables and color the patches to a base-color
4 S% H% I/ L- h ask patches
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set intersection? false8 T& \; y1 l2 k Y2 ~- t, y
set auto? false0 o' p$ ?! J) H
set green-light-up? true
5 X- J. E! x0 ]2 {, } set my-row -1
4 Q+ Q1 D; S& y set my-column -1
. O* p8 u1 X$ m) P, @7 z) x% t set my-phase -1* ^0 g/ k1 A. L9 f) W% E
set pcolor brown + 34 {6 _- Q- u( L! h
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;; initialize the global variables that hold patch agentsets
. k& F9 e; d6 v. S set roads patches with% H- @- R9 f& `; k. w
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or; b5 f$ w& g) B2 }. E6 d
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 J6 O! y1 C: s5 b) |# W( \2 [ set intersections roads with( t2 ]$ J% C! @7 Y2 w
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
$ Q V' t0 P$ J$ E (floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ L' W8 _+ d+ ?) R
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ask roads [ set pcolor white ]+ v: D* F6 C4 Y& ` J( Z6 ]! L
setup-intersections2 T8 g* M5 S7 L4 L: k3 V5 G
end
, b5 x( P9 s7 W1 l' g$ x( a其中定义道路的句子,如下所示,是什么意思啊?
2 ~ }8 Y- j z6 V9 y8 U set roads patches with
4 A p! `, F4 O ~. w [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or9 ?; b' L# y; z& W. M4 T$ [ f
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, R3 i# K. n8 q; v: R$ e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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