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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。
! j0 {$ U% d* x+ T% Y9 ?netlogo自带的social science--traffic grid这一例子当中,# @2 P5 t- |. K8 D2 e! W
globals* W$ N' t% c( x9 B( s. @
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; d: b" U1 \8 G( I grid-x-inc ;; the amount of patches in between two roads in the x direction2 k) p' `, i% G$ ~4 C, |7 q
grid-y-inc ;; the amount of patches in between two roads in the y direction% p1 D# T2 ~* _! R
acceleration ;; the constant that controls how much a car speeds up or slows down by if
: m" Q2 E' a& e2 C' e6 T, f3 c3 U ;; it is to accelerate or decelerate) K$ S6 d8 ^" @- u$ s' }
phase ;; keeps track of the phase
% j' F4 y6 C3 }3 B3 }$ Y! X7 K& y/ Z num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure. R/ D6 q$ H. D7 f6 v! L5 z
current-light ;; the currently selected light
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% d: y' L* F7 d+ G ;; patch agentsets
$ }" Z1 z- X, M9 S intersections ;; agentset containing the patches that are intersections) y# V6 G: Y, G5 j) [, O- N
roads ;; agentset containing the patches that are roads
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) o7 W' Y, H% i* O* tturtles-own0 s# m {% |) G+ y0 f, p
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speed ;; the speed of the turtle
: x9 b9 z. { `$ O0 d9 z/ U up-car? ;; true if the turtle moves downwards and false if it moves to the right
5 q0 M3 X* `" v/ p+ q" J7 | wait-time ;; the amount of time since the last time a turtle has moved4 j1 [! a$ J% t o' H# b( ~5 H% ^
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patches-own. S2 s- r) f, a0 \) Q9 M
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- r% q3 x- h E+ A( c2 h, h; T intersection? ;; true if the patch is at the intersection of two roads
( O4 Q6 v$ y5 E2 w+ c! v7 a$ t, t" E green-light-up? ;; true if the green light is above the intersection. otherwise, false.( ?7 x, ~+ q# U
;; false for a non-intersection patches.
' E* A1 L8 @; H# f my-row ;; the row of the intersection counting from the upper left corner of the8 M1 g2 m6 c$ y
;; world. -1 for non-intersection patches.
_5 _- t6 \2 D4 V my-column ;; the column of the intersection counting from the upper left corner of the
0 M6 o/ P2 H _* t7 n ;; world. -1 for non-intersection patches.' z* X4 L ]# J5 v J: q+ j
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
- l. I7 h2 b& J% q0 K! F0 P auto? ;; whether or not this intersection will switch automatically.
3 n# ?+ O p0 T2 i H, G ;; false for non-intersection patches.) u1 W; r5 O2 K: Y( i+ c V3 c
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- X6 o! d6 j; k' ]5 q;;;;;;;;;;;;;;;;;;;;;;- P7 N; D7 j8 _0 E1 C
;; Setup Procedures ;;
2 z: X4 P& }+ I" C/ N$ Q& h$ J;;;;;;;;;;;;;;;;;;;;;;% C+ g2 }. t8 j/ n! W' x
, R# i; g7 v7 L, \;; Initialize the display by giving the global and patch variables initial values.0 W2 U* j" d7 K( s( C
;; Create num-cars of turtles if there are enough road patches for one turtle to
% @& O+ G; T. |4 B$ z ?;; be created per road patch. Set up the plots.
: T( }- s# N* b6 V9 Pto setup
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables% W b' u' U6 x- R. o
setup-patches
3 y- x/ N |5 y& ]( t make-current one-of intersections: _$ M R$ c6 h
label-current4 [ h7 w5 _/ c+ k& h0 v
' b0 ~6 Y9 z9 V" [3 ^% u set-default-shape turtles "car"
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- ]$ `1 Z6 O) n' O/ [* L7 r } if (num-cars > count roads)5 G b* M. R k1 I7 T" Y$ ~( e* p
[
' i5 g4 C: @1 T( R5 v! A user-message (word "There are too many cars for the amount of "
y3 L/ P: i) c% V0 \! g "road. Either increase the amount of roads "8 L9 a" N% l9 C4 j w# v5 f' X
"by increasing the GRID-SIZE-X or ". F8 C% ^5 A+ l9 e% v
"GRID-SIZE-Y sliders, or decrease the "2 {. m e% {1 P1 N% ^; o
"number of cars by lowering the NUMBER slider.\n"
0 }# d7 O) J4 v, ~ "The setup has stopped.")
; w& S* V" P" Z: N stop
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% m0 C0 z9 r" {5 I ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
7 r p/ p$ i v! J$ d: m5 s9 i. g crt num-cars
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setup-cars+ D# B, e9 U6 ^6 _: L; x8 w
set-car-color6 P+ s5 f; r% T; ?- _
record-data
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;; give the turtles an initial speed
. f1 @* Y" f5 Y8 @( o9 |8 q6 I ask turtles [ set-car-speed ]
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8 |1 S: t) [4 P/ ]) K; h, K# M& [ reset-ticks
% B1 K, l7 C& @' ^! Cend
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5 \7 l/ l4 r. B" j$ a$ X9 g" n;; Initialize the global variables to appropriate values; u- r7 I/ M8 k8 x7 `9 Y
to setup-globals
6 h3 s- u g5 t8 ]8 \" [ set current-light nobody ;; just for now, since there are no lights yet( z; O0 F/ H" M) ?
set phase 0
; \7 l _, }; w* S2 v set num-cars-stopped 0$ {+ u, }" A9 f7 i/ G% o, r
set grid-x-inc world-width / grid-size-x
0 w7 P- U/ m: x! v2 u3 i set grid-y-inc world-height / grid-size-y% ~2 u& X& o. K; B9 G
* d( K$ B1 m6 J ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary9 O; Y5 ^8 V4 n: w0 A
set acceleration 0.099
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) ? C& [- Y7 l# G;; Make the patches have appropriate colors, set up the roads and intersections agentsets,6 S, {* @8 V/ R% C0 x4 y* \& N# M
;; and initialize the traffic lights to one setting
) C. C2 v" s: |: K; c. tto setup-patches a+ w6 f- ~4 `/ V& v* y
;; initialize the patch-owned variables and color the patches to a base-color& Z+ Q8 R- d, f, W
ask patches8 x/ s% P2 R3 s% h+ z. v
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set intersection? false
3 l4 g# v5 O3 \$ z/ V6 B0 | set auto? false5 A1 U8 k1 Z% Z# ~3 Y: Z& Q
set green-light-up? true
3 e m9 K) A T4 V- X ~ j* L set my-row -1: }3 d: j, _: p& [
set my-column -1
3 X M, _+ |: y |4 H set my-phase -1) N+ w" } w# t
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
0 E/ c( }" ~) Y set roads patches with
2 q' h' n' o& P [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or6 A5 P# o( ]3 J
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ K* m) g: o C; i set intersections roads with
% Q. X3 s( e' f: }4 }: A [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
, |* ]0 V: O' }1 H (floor((pycor + max-pycor) mod grid-y-inc) = 0)], R4 ~8 D, y/ o
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ask roads [ set pcolor white ]! C4 y& c2 E. l: T* m$ A' {
setup-intersections+ C- S0 I& J4 m( |% r
end1 c) u4 g5 Z6 z+ @+ `& |% r( n
其中定义道路的句子,如下所示,是什么意思啊?( i$ n! Y- u# @' b$ z4 p
set roads patches with
5 {- e% r' Z1 ^& f/ A [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 |+ ?3 D I$ e (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; d! k+ [6 P' q: T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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