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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。
. m5 e8 K3 F- N! z7 d& J( Ynetlogo自带的social science--traffic grid这一例子当中,
& n$ T$ h- E w+ @) z1 fglobals
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* G9 C7 x- d( I8 A6 [* \ grid-x-inc ;; the amount of patches in between two roads in the x direction0 h' X% D9 K# T& ]3 I
grid-y-inc ;; the amount of patches in between two roads in the y direction
% u, W3 y6 h0 n/ J- R; P/ }4 | acceleration ;; the constant that controls how much a car speeds up or slows down by if- r' I) j* \7 e
;; it is to accelerate or decelerate' r7 Z9 K* u7 h% Y$ m k3 I7 t
phase ;; keeps track of the phase2 g# g- `$ g1 B
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
; ?" ? S9 @' s6 k current-light ;; the currently selected light/ _7 ]- V& a5 y i1 ^8 z
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;; patch agentsets L; v2 Z" n* D+ Z7 [1 ?
intersections ;; agentset containing the patches that are intersections
) f5 p9 w- d. o1 s" }# B7 R* o roads ;; agentset containing the patches that are roads( H1 D4 c0 U, I/ k6 F k: C
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turtles-own
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speed ;; the speed of the turtle
: W" S2 i* X& g# m" [5 V% m up-car? ;; true if the turtle moves downwards and false if it moves to the right$ y( B7 e0 h& x9 v0 ~4 O
wait-time ;; the amount of time since the last time a turtle has moved K% A' G3 F1 _; E; j
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1 E& w( c: t8 r4 x# fpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
+ ~5 D# V% x3 D7 e* L green-light-up? ;; true if the green light is above the intersection. otherwise, false.; Z+ ~4 y" }+ r5 D6 H
;; false for a non-intersection patches.7 G1 N; k9 y% Z0 G& V1 u* }: V
my-row ;; the row of the intersection counting from the upper left corner of the" Y3 z* c9 h$ e* N% S
;; world. -1 for non-intersection patches.
, E6 v' @1 s, s3 X- p my-column ;; the column of the intersection counting from the upper left corner of the
1 T- U5 W' e* ^! z6 Y ;; world. -1 for non-intersection patches.
- q+ g2 ~& d& c0 Y my-phase ;; the phase for the intersection. -1 for non-intersection patches.
4 x6 W; h; Q* P auto? ;; whether or not this intersection will switch automatically.6 z: b0 X2 t1 `5 ?
;; false for non-intersection patches.
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6 s' P! k" ]# Y, S5 e& y% C9 n;;;;;;;;;;;;;;;;;;;;;;
6 w+ ^0 d- N! C;; Setup Procedures ;;* @+ C. a9 L8 }
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/ D* J( } j8 A6 V4 }! | Y;; Initialize the display by giving the global and patch variables initial values.8 T, S6 j! G2 L& @0 @) V
;; Create num-cars of turtles if there are enough road patches for one turtle to
6 w, Z' ~% {6 k8 L- x; U5 C2 y! Z: O;; be created per road patch. Set up the plots.
6 e9 v" e) [* a9 L% ~8 e7 n. C, oto setup- t. e4 a+ S7 g, ^, s2 _9 d
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setup-globals; k7 z b, H2 @
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;; First we ask the patches to draw themselves and set up a few variables
/ K0 w, `9 w+ Z( H: M, {2 e setup-patches
; N. H( e, i) i# g! p) C7 A" ~ make-current one-of intersections( H* x8 m& I% h; M% P
label-current# U: ?' F4 I$ I, u$ i9 B
5 s1 n" {% b! o. Q! P1 h set-default-shape turtles "car"# j. F; k$ }, X* k, ?! ^
6 }% p/ b# j9 z/ H/ z) p if (num-cars > count roads) ~- [3 h3 r2 i( @/ p. q
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+ u2 {2 @1 w, M% M1 M/ [ user-message (word "There are too many cars for the amount of "+ w, A: b, V0 ]2 j* ]) q+ A8 {
"road. Either increase the amount of roads "
0 M7 l- a2 b: |/ x6 K1 i/ h "by increasing the GRID-SIZE-X or "$ x: I; f/ O& Q* C% X& |% _" E( ~
"GRID-SIZE-Y sliders, or decrease the "
, R8 E$ M1 x+ h( l* @% ` "number of cars by lowering the NUMBER slider.\n"! Z b! O2 c& J9 ?+ p
"The setup has stopped.")
5 a, y0 D& W/ k" A: d; x# | stop* K' k) m) n# @9 ^. J7 V
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color" I9 F3 M0 x5 n
crt num-cars2 I0 |1 z6 m9 S' P" C
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setup-cars" _) Q/ @: S' a: M9 Z
set-car-color
+ {" p9 _( k* z. i, t record-data
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;; give the turtles an initial speed
7 U( D, k! i9 {, Z5 u ask turtles [ set-car-speed ]! q! E1 X' A5 d d
; a; x3 V: a) d* N' U reset-ticks
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/ j) e4 T7 R% u+ [;; Initialize the global variables to appropriate values
% }' i3 h8 W6 w! Q. s: mto setup-globals
3 H! z7 ^4 M0 f) {, ] set current-light nobody ;; just for now, since there are no lights yet
% P0 X1 K% {! n* Z7 P8 d) k6 E; P set phase 0! n9 E2 L9 k' m" r y
set num-cars-stopped 0
/ Z+ l% k) [+ u) M7 }, P set grid-x-inc world-width / grid-size-x
0 @1 a7 n# p0 n3 l5 c4 d6 } set grid-y-inc world-height / grid-size-y# r* U0 N# c$ v1 ~) L
- {+ q7 y5 G+ k- t ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
) x$ g2 |9 e' i N set acceleration 0.099
4 M9 g! M# u& A; Z9 bend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,& j! H9 ]7 i- c
;; and initialize the traffic lights to one setting% e3 T8 v% U5 \5 i4 d
to setup-patches
, \5 [, |- s0 B8 z+ q& N8 j' f8 K ;; initialize the patch-owned variables and color the patches to a base-color
5 D; \6 v, z; o7 y7 z+ Y' z' Z ask patches
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; A, f0 }2 V" z. ^4 B set intersection? false$ `/ ?8 d% M2 B; q% H0 t; ~
set auto? false
7 j# r; x8 b" O, k) G: {% q) g set green-light-up? true
) i6 b7 \ ]5 D2 ? set my-row -1* A; a9 X& Z6 V" |6 L' b9 k, ~
set my-column -1) h4 Y1 s, h7 G: y6 g( I
set my-phase -19 }+ @5 Y4 p7 c% ?5 S6 b2 P
set pcolor brown + 3
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1 F; P" l. h d) D4 ], j6 r ;; initialize the global variables that hold patch agentsets
1 C. X& {2 H7 t, G9 R set roads patches with
% e B |4 N J P0 Y0 l: o [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 B. s8 y" ~" l6 x (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 Y9 W: o. q) }2 Z+ T) u; R1 e set intersections roads with
* z& v: f' g3 X8 j+ n2 S/ T) s- o [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and0 ?, j. e8 c* m
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]& E7 D$ F/ N4 |8 O8 r I+ X
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?5 `- f6 o$ h5 O
set roads patches with
/ ]0 K! H0 E0 F& o( Q% z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or# |0 Z+ N" G* Q6 o- X0 }
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ P) v! U: c; U/ T3 w6 Y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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