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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。3 ?) p6 A& K1 d, [% N8 |
netlogo自带的social science--traffic grid这一例子当中,
& ~; z& [# h: A2 Vglobals
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. ?. [. M3 F t3 h grid-x-inc ;; the amount of patches in between two roads in the x direction/ K6 ^0 A4 D1 z% _: R
grid-y-inc ;; the amount of patches in between two roads in the y direction
( e* v) M" P1 }2 L2 \ acceleration ;; the constant that controls how much a car speeds up or slows down by if {+ Y1 r: I: V- u+ S
;; it is to accelerate or decelerate' Q a. B# |: G4 v, q( P
phase ;; keeps track of the phase
% ~( I9 n* O& \0 j- S) b num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure0 [4 o# K- ^2 G7 O' m4 w" q# E
current-light ;; the currently selected light/ M) i: H8 a; I/ M/ L
- j$ w( N" f: i9 r' r) I ;; patch agentsets# I7 S! l8 P5 b+ |6 [
intersections ;; agentset containing the patches that are intersections; z+ g3 R5 U, |
roads ;; agentset containing the patches that are roads& L7 S; u/ e9 P3 V; J& E
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$ B$ B# J; M: C3 [# {7 \turtles-own9 s9 j1 P2 a. r% T
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speed ;; the speed of the turtle
! `; B; L% y' w+ \! B9 Z7 E up-car? ;; true if the turtle moves downwards and false if it moves to the right9 ^ ]8 F$ @( I9 `1 H
wait-time ;; the amount of time since the last time a turtle has moved! _2 a7 x; n+ B/ Q$ h9 k
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2 R3 j" p; w& O- P# Lpatches-own
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+ f( c. l8 b: w, K1 V intersection? ;; true if the patch is at the intersection of two roads8 a6 H/ B' Q, O0 A2 T
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
: p" o9 Z# W' l$ ^ ;; false for a non-intersection patches.. v: Q, }( W' V# c4 _
my-row ;; the row of the intersection counting from the upper left corner of the
8 ~' k e: r0 h, `; D( d, _2 v ;; world. -1 for non-intersection patches.
7 O% F h0 m) q6 Z J, _/ q my-column ;; the column of the intersection counting from the upper left corner of the
$ H: {, F& U; \5 i( m ;; world. -1 for non-intersection patches.! E) g' g: N$ X; n
my-phase ;; the phase for the intersection. -1 for non-intersection patches.$ O: V; m( p" L: t8 k
auto? ;; whether or not this intersection will switch automatically.
- \% q7 I4 F, x4 R: u ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
# h( H( y7 Y5 {;; Setup Procedures ;;- b |! ]* b) _& U; n7 a1 d- j
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;; Initialize the display by giving the global and patch variables initial values.
9 b& u! ?2 S1 A( K! Z, d;; Create num-cars of turtles if there are enough road patches for one turtle to
2 [2 Y) b' g& j' u8 b, n$ \;; be created per road patch. Set up the plots.9 d) l- j% A; l5 y: u! c( O
to setup! E2 R; B2 G# G8 U4 V5 D
ca
- F) }& [& [4 | U setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
. ^/ j h8 v$ p q. D setup-patches) u4 v+ e q. j% t4 x& r
make-current one-of intersections) q5 {! k% n# S
label-current. o; s: C5 L2 s3 E2 t
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set-default-shape turtles "car"
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. t. H7 \/ k* F, N$ m+ C. `7 y if (num-cars > count roads)" D; |- Y& d" Z4 f7 H
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user-message (word "There are too many cars for the amount of "" {0 I. z0 ^8 V$ E
"road. Either increase the amount of roads "; W; C: w# v- Q5 a' X8 ]
"by increasing the GRID-SIZE-X or "$ O/ r, t( Q8 n) @# W7 M# k# o
"GRID-SIZE-Y sliders, or decrease the "4 E& B4 }4 N2 x1 d% w0 w: H6 m
"number of cars by lowering the NUMBER slider.\n"
9 _& T1 r; f, J) _+ |1 E) c7 y "The setup has stopped.")
U" `$ e- p x2 c7 g stop0 H0 f9 ]' T- \( K& ]
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
) I; a; K0 a7 f+ n. Q crt num-cars _ P& [: ]+ f9 _0 p/ a1 v2 j* \
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setup-cars
1 u. G+ G9 b' I& u8 T1 U5 ? set-car-color
# }0 ~% _+ [: e, p# Z record-data* _& p' {/ z8 a' ^+ c
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;; give the turtles an initial speed
% ?" g' K8 a: g! D" W; S1 i ask turtles [ set-car-speed ]. O8 c+ R k3 ]- c% S
/ i( D6 t& `7 \' ]6 f0 T6 E reset-ticks
0 Q1 q6 x9 m3 C _end* V: G# c5 M+ X" E
, n; S! y- J3 d1 l" } a0 q) \;; Initialize the global variables to appropriate values
, U) k; S& F9 |8 [- }" W gto setup-globals( n5 Z8 ^' Q5 X
set current-light nobody ;; just for now, since there are no lights yet+ a) r% Q( a5 Z
set phase 0
3 g v! C9 E5 K5 M% j0 K D/ I set num-cars-stopped 0 u1 y; R- M2 N, \/ ^5 {- ?- Z
set grid-x-inc world-width / grid-size-x
8 m8 v! A' O' k; D0 ~ set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary7 p; O5 s& q3 s6 P3 {3 e; t
set acceleration 0.099
" ]! e5 V; Y6 j% s l( N% Mend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
5 t7 K6 M% L8 a, b& K;; and initialize the traffic lights to one setting
" g v+ `6 Z m) _2 l/ vto setup-patches5 Q8 s$ k' U/ L' N
;; initialize the patch-owned variables and color the patches to a base-color* J/ p) m/ a8 T. ?: \+ Z1 M
ask patches
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; [/ o6 i. M! G set intersection? false+ R" t3 o% D, r6 o; x! }5 o
set auto? false
9 I2 ^5 U( e( T' E' k+ L set green-light-up? true9 D* B* E% p8 p1 c; n4 X
set my-row -1
. I' a: l6 r; G# `3 \ set my-column -1/ _' R; M3 S, c: W4 K0 o
set my-phase -1
, ?/ P* |/ [0 d" N9 C9 @" D- J$ j set pcolor brown + 3* _5 }( C3 n3 F& r C
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;; initialize the global variables that hold patch agentsets
: c( R$ @( M) f8 s4 k5 s set roads patches with
& c N2 w, A0 ^ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! d2 l/ ^0 J" j1 b (floor((pycor + max-pycor) mod grid-y-inc) = 0)]. T) a/ l- w6 j3 j" Y
set intersections roads with
4 p& I8 U$ h& k: F3 r( N [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and! j. H* `3 K0 a* [( ?8 s# |5 B, [9 E* ?
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]% K/ n" t5 Q5 Q( |" m
setup-intersections `" \: b/ s" E- e) p- B" R
end
2 M& Z0 r2 W/ `: _# {% E1 |3 ^其中定义道路的句子,如下所示,是什么意思啊?
1 ^6 Y& r( o1 y! y5 o* | set roads patches with
+ _, \* g$ N. r' h. s. o [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 p9 K8 i E8 h$ H' ^; B (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 ~# A8 E' h$ }2 s1 P2 W+ d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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