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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。7 m `" [1 r% k0 y6 ~9 t0 u7 ^
netlogo自带的social science--traffic grid这一例子当中,+ [9 @! c |1 Z8 U: Y
globals
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( ?* c8 H H- e5 Q% O* ` grid-x-inc ;; the amount of patches in between two roads in the x direction
9 K/ L4 q" m$ C8 Y/ h# k grid-y-inc ;; the amount of patches in between two roads in the y direction! p1 d! S! q1 R5 a
acceleration ;; the constant that controls how much a car speeds up or slows down by if3 H7 ~7 D* q& k4 u$ w" J% U
;; it is to accelerate or decelerate
+ S2 Y$ ]0 _3 s G/ a, n phase ;; keeps track of the phase
1 T0 i4 N. q* z- e: l0 }0 ?1 m0 K1 c num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure/ O% i. D/ p# A
current-light ;; the currently selected light& r, `' f" d' J' d: ~: I
' m" \# ~3 b$ g) V! ~ ;; patch agentsets1 R6 M$ F8 D8 h; g8 q
intersections ;; agentset containing the patches that are intersections5 d3 W/ l u- L& S' L4 ]! i
roads ;; agentset containing the patches that are roads5 m7 D3 Z8 ?% c0 |. o
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1 a A# Z: [! ~* t' Z' C' Jturtles-own4 `! [* z S( ~) F4 e5 E2 E; V
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speed ;; the speed of the turtle: o8 N0 t4 H- J* T
up-car? ;; true if the turtle moves downwards and false if it moves to the right g3 u7 V" \1 g3 x" n2 W
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
7 K# _1 `! _$ B% j# X+ u# k green-light-up? ;; true if the green light is above the intersection. otherwise, false.
5 L4 z1 r$ S+ i, B ;; false for a non-intersection patches.
( F- o8 n5 y2 v, M3 F5 w% L" W9 [9 r my-row ;; the row of the intersection counting from the upper left corner of the
& ]+ c* H; M4 j( v8 q* u( X* O ;; world. -1 for non-intersection patches.7 p6 z4 G" q& Y( s! i
my-column ;; the column of the intersection counting from the upper left corner of the% b6 x0 B) c2 c0 F2 z5 f
;; world. -1 for non-intersection patches.
. x" |* A' `3 z( f2 t' F# ? my-phase ;; the phase for the intersection. -1 for non-intersection patches.5 P2 R5 a1 L6 E! H! T# N
auto? ;; whether or not this intersection will switch automatically.
m+ y5 `8 Y/ P( u+ [1 w5 L ;; false for non-intersection patches.. \! u U; a4 V }3 O W
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;;;;;;;;;;;;;;;;;;;;;;, X- J6 \* g: T* f) m5 U
;; Setup Procedures ;;4 ?- Z$ E9 t: |8 `6 h+ D2 c; G
;;;;;;;;;;;;;;;;;;;;;;
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# t* c- b" K4 g- d& g) w5 w, K;; Initialize the display by giving the global and patch variables initial values.
/ p* U2 T' I3 y! Q;; Create num-cars of turtles if there are enough road patches for one turtle to8 A; E/ ?& g' k4 T8 c, V
;; be created per road patch. Set up the plots.2 R P. Y, B. X6 ^' f
to setup
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setup-globals3 [* t; @+ f |
0 O. i' Z/ ?4 F- l8 J+ E' \: t ;; First we ask the patches to draw themselves and set up a few variables
& M0 z9 V* S$ y% p$ T setup-patches& N1 o. C2 d6 X/ i! a
make-current one-of intersections
5 u" e& c9 O" d5 e" V label-current( j& U% x4 X5 s3 S' {; f; {& j
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set-default-shape turtles "car"
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v7 k/ J7 Q1 ]3 j1 S if (num-cars > count roads), Q- G! [" s) g+ m7 z( J
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user-message (word "There are too many cars for the amount of "
# f4 ~; R! Q: w8 r/ E "road. Either increase the amount of roads "
! v! V( L# K; _4 ]! j2 o. {2 P7 j "by increasing the GRID-SIZE-X or "( z8 w9 r; N% w8 G
"GRID-SIZE-Y sliders, or decrease the "
% \) q# J& H. m "number of cars by lowering the NUMBER slider.\n"
2 N: l. n6 N# ]9 L1 f1 D! e "The setup has stopped.")
6 ]1 u- }4 |# u; k; G% L5 g stop1 ~* X( ?# M% ?5 a9 b" j$ \
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2 s& o! S+ M+ w) g; W1 J: y3 ? ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
6 o- C8 u3 l1 ^% N* n, ^ crt num-cars8 I6 i/ h* }5 g9 Y3 B7 y A8 E5 d
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- K- M2 R5 X4 a& z, U set-car-color
1 G/ I+ ?! J X' E record-data
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;; give the turtles an initial speed+ N; @& j/ }# m& n$ _
ask turtles [ set-car-speed ]
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reset-ticks2 k) @9 p5 T' ]) ]) N( [( P" R1 t
end
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, R" Z2 I1 v7 g9 l# H* W' D;; Initialize the global variables to appropriate values
2 M/ _) g: ^% v# mto setup-globals
m+ i7 F! v1 w0 m$ k6 A set current-light nobody ;; just for now, since there are no lights yet
# i8 N' U. ~( k* m set phase 0) h# i: n& @- j0 v2 W8 O" U
set num-cars-stopped 0
P1 e# m" L/ t7 d4 l set grid-x-inc world-width / grid-size-x
" A9 K j* i3 N+ L3 X0 U! y* x- r 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 boundary
) G' x5 q. ~( h6 a" b set acceleration 0.0999 ?2 w+ \: o: N1 C$ [5 ?+ k
end$ V% H7 m+ u* m
$ h! X3 n5 E& B9 z" h;; Make the patches have appropriate colors, set up the roads and intersections agentsets,3 h! W$ L* [1 t5 q. F v7 V
;; and initialize the traffic lights to one setting
- U$ M1 v+ H4 s8 Fto setup-patches2 @* J7 i4 l( W! O* c' N4 C
;; initialize the patch-owned variables and color the patches to a base-color4 u# B+ l [# T' g: h" i# I3 {
ask patches
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# F% K( j( U8 u( ?3 e: f+ O, c set intersection? false# f' o9 I! N4 J* H
set auto? false! h0 K2 ?- b7 D$ o- I$ u, W0 V$ z
set green-light-up? true& q$ ^# z/ A/ A' P; Z
set my-row -1
1 @% Z* ^2 e* @8 d* X9 S3 H' T% \ set my-column -1
% {. K! ^$ B9 h$ X% l/ L! G$ q, i set my-phase -1
$ \. @) }& O: A& C0 M( n set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets5 O1 E% E7 _4 j% U: K) Z# |
set roads patches with
+ I3 M! A; o. |0 e [ d* J [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or0 M V2 \7 \6 J8 X2 a
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 t% t1 D5 v z- {0 H- C+ u
set intersections roads with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]% H/ @/ m i6 c" F1 i0 w7 _" b- Z
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ask roads [ set pcolor white ]5 \: `3 }% w: L! _/ O8 u0 t4 C/ m
setup-intersections9 s$ y6 D- `2 E* X; C8 l9 u% p
end. l3 G( P1 z8 s% v+ g$ R
其中定义道路的句子,如下所示,是什么意思啊?) Z+ k9 T! K& m, g( u5 I/ {5 |
set roads patches with
' J7 y6 \5 ~. }+ |0 T2 M4 w O* V [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" z6 r( X2 f" m2 E$ { Z0 c% { e (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* D( l. n% N- N" z6 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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