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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。' G) ^5 z" W, A$ P; A3 @
netlogo自带的social science--traffic grid这一例子当中,
' J; P) F) w3 Y9 }; a" X3 @. Pglobals) E9 ^+ a7 m! K. f5 |+ u; ^
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grid-x-inc ;; the amount of patches in between two roads in the x direction! i. Z5 h/ w3 y8 g& Y' P
grid-y-inc ;; the amount of patches in between two roads in the y direction( D7 A ^$ E& w9 z. \
acceleration ;; the constant that controls how much a car speeds up or slows down by if4 A3 l) C. ]; e
;; it is to accelerate or decelerate
* n4 B; T. [' R phase ;; keeps track of the phase
& l3 n7 g- Q( w* B; C! X num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure8 K/ I0 P& L) [# v
current-light ;; the currently selected light/ ~( W' w3 W1 K" U9 W$ U
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;; patch agentsets4 J0 W' u3 _3 _, _% G8 c* \
intersections ;; agentset containing the patches that are intersections
1 {6 _4 c' {& Q4 Y8 _ roads ;; agentset containing the patches that are roads% \1 g$ T' j7 m9 h
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turtles-own: ?6 }( M' m* I$ L
[
0 p! h' u2 h1 e, S! ^ speed ;; the speed of the turtle
( Y; b( x! _2 C up-car? ;; true if the turtle moves downwards and false if it moves to the right& t3 ]6 L( a6 j4 z
wait-time ;; the amount of time since the last time a turtle has moved9 G! l+ m; O3 }3 N- [0 G
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads2 ^. V# l V2 m! Z& R% F
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
1 G9 Y2 v' Q6 G( v ;; false for a non-intersection patches.
" P. H7 L3 U( N% K my-row ;; the row of the intersection counting from the upper left corner of the
7 H! `) n% P2 q ;; world. -1 for non-intersection patches.- l' ?' T, D0 Z+ d
my-column ;; the column of the intersection counting from the upper left corner of the9 {" u) l& _8 m" E V5 p
;; world. -1 for non-intersection patches.+ {6 B' V+ J, b# C! d
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
' _9 u' L0 ~% f9 _4 u auto? ;; whether or not this intersection will switch automatically.1 r& n& W1 u8 W
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
- f! K. Z$ ^; h# t# h/ f) Z6 h;; Setup Procedures ;;& n" V9 O( ?9 b: j: S
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
/ f. K; C: L: {& f;; Create num-cars of turtles if there are enough road patches for one turtle to0 h9 T2 ~; w! Y* ?
;; be created per road patch. Set up the plots.
8 n4 r+ z; g& F, Ato setup
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+ N) n& Z- I+ r/ B+ s; D setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
2 v6 ^% D' p$ S1 y: L setup-patches
. K7 Z% Q+ M; r6 S* h" R8 h make-current one-of intersections
6 q! `; c7 r% m" S! b+ T$ Q label-current
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set-default-shape turtles "car"! L. a/ K3 {' P) O! |2 {" `
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if (num-cars > count roads)+ L( t. _ }! J$ N* I+ r9 i8 F
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user-message (word "There are too many cars for the amount of "+ C2 w, ^1 ]8 M* j% f
"road. Either increase the amount of roads "
- _) M) ]- |, M( r+ A2 q' ^# E "by increasing the GRID-SIZE-X or "
3 _3 a0 N' {' m$ [4 ], X "GRID-SIZE-Y sliders, or decrease the "" r Y' a- @. F9 Z7 T( N$ z
"number of cars by lowering the NUMBER slider.\n"* I5 d% X% Y* L, H# i7 z
"The setup has stopped.")
2 Y- u5 W: Q7 w1 y3 t2 M) \, U stop% f3 _1 a4 O' w. A- x3 G- `; U
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color& ~7 w9 A9 ?9 W( w; W, g3 M
crt num-cars
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/ L& Y# F1 z- _ setup-cars% |) {& y: ^; H
set-car-color
: |* Q1 Z9 E/ P4 ^ q record-data/ K$ S" V6 e) l, {6 H2 ]( Y
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& \, ^/ _2 e7 `, @* k ;; give the turtles an initial speed' {' ]2 o' \' w+ X, K
ask turtles [ set-car-speed ]
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0 p5 F6 _6 b1 f% {! Y reset-ticks0 x! [& ^* m; }- ~; S. |' F9 Q& E& L
end' g Z( E* f2 [) V
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;; Initialize the global variables to appropriate values& q9 g) O* B' k$ y# R6 k4 E0 Y
to setup-globals+ q" f7 b# c; O/ M! h/ D
set current-light nobody ;; just for now, since there are no lights yet( S1 g; Z% H7 w+ {3 ?, x( I. Q
set phase 0
! q) T, K: O; l4 J: G: Q3 u) T set num-cars-stopped 03 F; N/ N! E( }
set grid-x-inc world-width / grid-size-x2 _) ^! h2 p4 g9 Q* X( q! s* j: P
set grid-y-inc world-height / grid-size-y. v: G* g$ y! T) v; V
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
2 O4 S1 w5 O, }, l! Y- ~9 F# y set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,8 @) o5 @/ z( L4 }% u8 m- A' a& }
;; and initialize the traffic lights to one setting
1 M( t) r; r7 U' d5 d' g* C$ bto setup-patches4 m p% }/ H1 w. K; e$ Y1 g
;; initialize the patch-owned variables and color the patches to a base-color
8 ]# o6 ^6 r, ~" ?. p ask patches
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set intersection? false
4 m+ t0 p/ _% K5 Y$ R6 J7 ]+ l7 } set auto? false. o& e* b( n5 I) ~6 x' ?) k# A
set green-light-up? true
! Y8 P0 H% [2 ]6 k- G7 D set my-row -1
- G( k* C2 u" U set my-column -1
; d+ e \9 h" [( V. Z6 k2 | set my-phase -1' `* b+ i. y4 T, h
set pcolor brown + 3. c" I: \+ ~2 H9 E9 V
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$ f9 }6 M" Y6 r& r ;; initialize the global variables that hold patch agentsets5 z" k& E+ |# J+ T& x$ S
set roads patches with, R0 [ H( a6 q6 a/ |5 |
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) i% [3 i3 p, F) U
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ Z8 a( r7 e$ b
set intersections roads with
* I# N/ s. O# ~( F' q/ j/ P; z1 o [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
! ^( g4 T3 c3 y* R+ B (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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( l/ t8 L* ]9 o* G; ]2 r ask roads [ set pcolor white ]
: f" B2 K2 s' V* J9 B8 Y. i% v! t; h setup-intersections9 [# E: K6 ~* q' v) u' Y
end4 H+ @( u, C6 R1 P" G
其中定义道路的句子,如下所示,是什么意思啊?. E9 X9 i5 j4 Q4 F9 j3 N) e
set roads patches with
" A5 z% f& N% A- ] [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or- ~4 J# h" ?" ^1 C
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; A: [, `, ]4 F! V6 Y/ G+ ~- z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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