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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。0 g& }' Q; I' D
netlogo自带的social science--traffic grid这一例子当中,
& L+ Y, {- t% `% ?globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
7 m# u9 y6 m+ s) z) [" @$ j/ v grid-y-inc ;; the amount of patches in between two roads in the y direction, m) U% z2 j% c2 V: x- X) H W* r" j+ V
acceleration ;; the constant that controls how much a car speeds up or slows down by if7 }- J0 K5 d# t) b2 d/ f
;; it is to accelerate or decelerate
% j6 t& n1 T! f& m+ e& j phase ;; keeps track of the phase; \8 Q" g( v9 S: Z# d
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
5 P* {, {( m0 V3 T0 a# s, a9 t current-light ;; the currently selected light
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;; patch agentsets
0 J1 j$ t6 o8 R9 V! _( L* p intersections ;; agentset containing the patches that are intersections
. t; o( V6 y- h( O# V* t- U6 z. G roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle
) [7 ?, ^6 q- ^0 J8 _/ _ I7 L' M up-car? ;; true if the turtle moves downwards and false if it moves to the right) u X' {( G& o6 [! x: ?
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
" A. K7 \! \0 O- \- M6 Z green-light-up? ;; true if the green light is above the intersection. otherwise, false.
3 a& Q5 F$ J. [9 j' E2 w m0 o# p ;; false for a non-intersection patches.
( T% A* `9 v: h) M' | my-row ;; the row of the intersection counting from the upper left corner of the& I2 G7 K/ ?5 I/ g
;; world. -1 for non-intersection patches.8 S# }! D" L: S/ o U6 f* z
my-column ;; the column of the intersection counting from the upper left corner of the F7 Y+ |( ?( f! ?4 t1 w
;; world. -1 for non-intersection patches.! `! q: i) }/ n1 F% d9 G
my-phase ;; the phase for the intersection. -1 for non-intersection patches.4 y9 n6 o( |! ^$ J( m, G( C4 J0 t
auto? ;; whether or not this intersection will switch automatically.
7 Q5 P" ^! a+ f( Y7 L5 D& Q j# U ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
+ C5 M& l/ c, \3 X: c6 v;; Setup Procedures ;;
( _9 `& z' H2 g# r6 e;;;;;;;;;;;;;;;;;;;;;;. {/ x) @9 {8 U) ?
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;; Initialize the display by giving the global and patch variables initial values.
; a4 K: C; g' [" w;; Create num-cars of turtles if there are enough road patches for one turtle to# F( n; k" [) B& h: x0 r
;; be created per road patch. Set up the plots.
2 ~, w% f3 u! @# G9 Eto setup) P3 u7 i) O: |, K" c2 `; j, ~* e
ca
& }. w. i, n5 w! e! ] setup-globals
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; R+ ?- A$ h3 P# w* r4 e% i1 G ;; First we ask the patches to draw themselves and set up a few variables
! f$ @& j. n0 R' Z) V/ Q. d! Y setup-patches
4 u' b" o3 \+ _$ Y make-current one-of intersections6 @" N% C" {5 e) d
label-current
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set-default-shape turtles "car"7 Y0 S# A: V1 X4 k) e& S
- T" S# V0 }) i0 [# ?4 q if (num-cars > count roads)
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/ P4 t0 N0 c% t, ] b! b user-message (word "There are too many cars for the amount of "; K2 `+ F4 C# j7 }. u) b- _
"road. Either increase the amount of roads "9 @4 @0 E X3 P) u( W; Z0 W
"by increasing the GRID-SIZE-X or "5 A7 d8 ?& a$ z6 X5 n- G+ e+ [7 ~: a
"GRID-SIZE-Y sliders, or decrease the "9 Y! z# e9 `0 G
"number of cars by lowering the NUMBER slider.\n"8 i0 G' _- H( D( A: ?1 ~' m; l; U
"The setup has stopped.")
* c# J8 a" Y+ ^( Q$ {! Q, q stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
0 f* k; b$ ]; T4 t. M3 J/ \ crt num-cars4 I, `! r" F' s, ~) z
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setup-cars' _9 I5 e5 t" q8 ~% O
set-car-color
+ S! k) R! l% V8 {6 W record-data' l$ q& I% M; M( e6 Q( C T
]
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;; give the turtles an initial speed
3 S( t5 I8 l6 a8 o( p+ u ask turtles [ set-car-speed ]
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reset-ticks
! ?( ~+ p! u, h9 ^" F/ ]end
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;; Initialize the global variables to appropriate values
9 B9 i* I, _. n7 t& k: [to setup-globals3 z% A$ Z- L! R. g- |, E
set current-light nobody ;; just for now, since there are no lights yet: O8 S5 R) ~6 ?& q3 u
set phase 0
8 e% R Y" c9 @4 f" a# ] set num-cars-stopped 0
* {/ r9 }, T* k g; r set grid-x-inc world-width / grid-size-x
& B2 I& p. @+ n& T set grid-y-inc world-height / grid-size-y1 p+ {' m" ^" H5 }
2 g5 s: X. ?' h3 W& t9 S3 V6 I: \ ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
2 s' |# i3 p9 l- M, @ set acceleration 0.099
w) M8 ^! `7 c6 p9 K @! send
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
4 A) s5 q8 g& b0 J; n5 y8 I2 u;; and initialize the traffic lights to one setting5 ~/ G2 }: T* v7 }% U2 C, y j
to setup-patches/ f3 Z& ~# F/ X% ] _
;; initialize the patch-owned variables and color the patches to a base-color
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[
0 ]. t8 q3 m% P# W8 \6 H' k9 E set intersection? false
# q" F) C3 D& j9 w4 p8 j set auto? false
8 J& d- K( ]$ Y/ N ~: ~ set green-light-up? true
4 D* r9 h( E1 m: N/ H- ` set my-row -1( ]! W& @- ?4 ~' k0 e& L3 Y
set my-column -1
2 L" k: g: l& i1 r: i/ t) V set my-phase -1$ D, A: p. q x1 J1 z
set pcolor brown + 3& y' s, r. k$ f
]
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;; initialize the global variables that hold patch agentsets$ I0 d" S# o2 m" v! |8 N
set roads patches with
" S7 Y: }3 j/ H9 m g [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! K3 l, b1 r( [' _/ L8 O
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; o: ]5 M5 m- M) f+ I) o set intersections roads with
% j" [4 ~6 [. P [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
# Z" l& R) T5 x1 @ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]% B# N; H7 g5 t J2 \
7 d7 ?. R& j1 L ask roads [ set pcolor white ]& g. h; v9 Y, A1 k9 d ?: e( O
setup-intersections
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7 V2 T8 [+ W9 N5 R+ S# }: V+ b1 z其中定义道路的句子,如下所示,是什么意思啊?& } A8 k& b0 Q1 V
set roads patches with
0 n0 k0 c& s3 F7 P1 v [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 K. Z$ l N% y4 T (floor((pycor + max-pycor) mod grid-y-inc) = 0)]' j& v) t6 X, L. U- i* D/ ~# X
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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