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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' C( I* b% g2 b
netlogo自带的social science--traffic grid这一例子当中,
- R4 N8 T& W( E1 r9 d$ ^" P3 bglobals
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5 @- A7 R8 P& a) A7 }0 m7 A4 t grid-x-inc ;; the amount of patches in between two roads in the x direction+ b9 [' A, U+ ~5 V; Y3 @1 g* v
grid-y-inc ;; the amount of patches in between two roads in the y direction0 w* v1 ^% w& I+ y- W
acceleration ;; the constant that controls how much a car speeds up or slows down by if
1 q+ n/ a. \! T3 a( G% V: P( Z ;; it is to accelerate or decelerate
$ Z( m# v, i& `; U+ s, p5 a( ^& U" O' v3 w phase ;; keeps track of the phase A) _3 k6 P* g: p
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure3 m* x# U" z0 h1 w
current-light ;; the currently selected light4 _3 M+ N+ u& q9 f! Y
) P6 H' v! H& L+ `4 i+ |3 E ;; patch agentsets$ j. Y" w& P! I* M& x" S" p, U
intersections ;; agentset containing the patches that are intersections
6 {8 T) T- ?4 s8 X7 B roads ;; agentset containing the patches that are roads
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turtles-own3 P: T3 _' i( X, b2 C
[
; z' |! l' a7 A/ C. e speed ;; the speed of the turtle
* G" H, f& @- r up-car? ;; true if the turtle moves downwards and false if it moves to the right6 c' j" W- X3 A3 t) G
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads: U% ^0 d( `2 b$ j( y7 y
green-light-up? ;; true if the green light is above the intersection. otherwise, false.# h, j& X7 O+ T. ^* j% n: [
;; false for a non-intersection patches.
s5 z$ e4 i2 W my-row ;; the row of the intersection counting from the upper left corner of the% M6 K7 N) H6 D( V
;; world. -1 for non-intersection patches.# D' G7 J2 X- o0 M
my-column ;; the column of the intersection counting from the upper left corner of the0 t; g! T4 a h8 x4 k9 M
;; world. -1 for non-intersection patches.
7 @% P! W u t- p my-phase ;; the phase for the intersection. -1 for non-intersection patches.
( {! r# b! R& k2 h' ]; N$ U auto? ;; whether or not this intersection will switch automatically.* v, O% L$ X" y2 O
;; false for non-intersection patches.
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! `% G! s# M& |+ G+ T' F6 w2 L+ ];;;;;;;;;;;;;;;;;;;;;;7 s/ v7 N. n( O) w E* S3 K9 }3 g
;; Setup Procedures ;;- X6 w) W: Q D9 K8 \
;;;;;;;;;;;;;;;;;;;;;;3 b F3 |: n8 V! r
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;; Initialize the display by giving the global and patch variables initial values.
; f$ T% c, V. Z% r9 j* r;; Create num-cars of turtles if there are enough road patches for one turtle to
; [, E6 R6 U/ @+ b) `;; be created per road patch. Set up the plots.! n2 h! s5 F/ }5 i5 Q- z% c8 Z
to setup% x3 d+ p. W4 T* _# G! l
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setup-globals
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9 I, ~- O& Z* x3 }0 r) c2 p ;; First we ask the patches to draw themselves and set up a few variables& i4 O* D$ F; Y( i& }5 n
setup-patches# K* X! H2 P+ w% n
make-current one-of intersections
$ P2 M* B, h+ p( n( a3 |! ` label-current
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" W7 \0 e+ j# s% i+ N4 X5 S, D set-default-shape turtles "car"
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if (num-cars > count roads)) A8 @% P3 f* p4 Q& }8 X- o
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user-message (word "There are too many cars for the amount of "
0 P* {- X# N# U6 X% U$ r "road. Either increase the amount of roads "; p) y% P4 V9 y1 U7 X
"by increasing the GRID-SIZE-X or "+ x) v9 L- Q6 e. i
"GRID-SIZE-Y sliders, or decrease the "
- j4 A$ H9 H- C4 @$ v "number of cars by lowering the NUMBER slider.\n"
$ Y, V, Q+ ^7 {, Z, ^. S "The setup has stopped.")
6 }# A, }1 y. }5 g0 q stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
" J# u+ _6 ]2 |/ X crt num-cars9 D, s' G" i& B+ S# U" Y
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4 o1 Y! _ `; X0 }! {. A setup-cars' I+ t3 A; q e' d6 x
set-car-color( H; V2 E9 Z0 y h/ K. o9 ]( G
record-data
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;; give the turtles an initial speed: P! I2 W6 g) ]/ [
ask turtles [ set-car-speed ]
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reset-ticks% S- ]9 |' u; q+ o+ Y, h! v
end
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;; Initialize the global variables to appropriate values
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?" Y6 `+ N* M* e set current-light nobody ;; just for now, since there are no lights yet. r: g9 }; J# |, J' ?
set phase 0
( I+ V& D7 ^8 ~' w/ q8 L& S set num-cars-stopped 0
% Y3 k' D4 I$ F, e& f5 m" a( g set grid-x-inc world-width / grid-size-x
$ S1 y5 w b+ H9 Y8 C8 t u! W* v set grid-y-inc world-height / grid-size-y
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, O' ~, i% V8 B! b3 P7 U5 j8 j' j ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary! w8 |% L4 ?' _" H" ^
set acceleration 0.099
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, x& o# H* V9 b1 f;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
0 x% A- V7 T3 I8 R: v4 k* o;; and initialize the traffic lights to one setting) ~% x& C2 _( A2 Q: l
to setup-patches
' I4 y/ D, e$ w6 ` ;; initialize the patch-owned variables and color the patches to a base-color# O' L/ u, F) w' V& ?- f) N
ask patches& ?, @/ C( m, l' l ]
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3 o. l. F' }3 L X8 {: d8 o7 a2 n set intersection? false
, f! m* H6 r' {8 \- V set auto? false2 T; M/ [8 r7 p" [ b$ x1 n2 ~0 S0 q3 U
set green-light-up? true+ d2 ^- V$ l6 D& W# |: k i# f
set my-row -1
& G3 Q( W* ?% W+ J. S set my-column -1
G% ^/ X5 S4 { set my-phase -16 Z, u, t: L4 p6 T: N' m
set pcolor brown + 3# @& }0 h' a7 M1 b7 s4 ^8 P
]
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0 {/ ]- G- b- ~# N ;; initialize the global variables that hold patch agentsets2 K5 s) y; r( z5 y: }3 Q
set roads patches with
6 [7 h8 ^3 x2 g [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or8 a* g9 H! x) ~* {+ u+ k" |
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]( n7 M8 C# A( V; Q3 e
set intersections roads with% G( Z9 _+ B+ w
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
) ? G1 o9 _' B+ B+ T9 L (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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u$ S# u0 y( q8 w. {6 g6 g) z) w ask roads [ set pcolor white ]" }/ J' E' S; |% e
setup-intersections7 ~2 x# P3 T9 ~ Z) f
end: _8 V6 M" x# b/ q3 r# F3 i
其中定义道路的句子,如下所示,是什么意思啊? y+ W3 p# l# h0 Q
set roads patches with
3 d, i9 Q- E2 P: ^- F( ^ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
3 c6 t7 |! Z1 _ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]& O5 l0 n$ N! N5 ?$ G, q; `+ ?
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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