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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 T( t6 X/ n# j- E# P ]
netlogo自带的social science--traffic grid这一例子当中,
- K- }/ Q1 E. sglobals% ~0 x8 O( d" s, g) j1 R! k' i
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0 S+ F5 }8 m) C0 `8 i grid-x-inc ;; the amount of patches in between two roads in the x direction
0 i( M9 i1 h3 h& O grid-y-inc ;; the amount of patches in between two roads in the y direction) \# Z- x* H" T) R w% v
acceleration ;; the constant that controls how much a car speeds up or slows down by if
3 d2 \: p; u h/ q- K! U: X' y7 c ;; it is to accelerate or decelerate( L+ t6 Q9 ~" Q8 e: M( Y) \
phase ;; keeps track of the phase7 g, E- J8 y" j3 l: C
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
5 [- Y! K8 d- ^- s" T" w7 o* y current-light ;; the currently selected light! s8 Y* S' f, e+ G2 i
: f$ k. F Z7 r! O& B8 m ;; patch agentsets) m5 [1 i9 O% o, T- m
intersections ;; agentset containing the patches that are intersections
' H# q2 k2 e) _5 i4 O; L. u roads ;; agentset containing the patches that are roads5 C: B3 H' P( X- N' ] h2 p
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+ G, C. f0 O% W! e& Jturtles-own. q% R' s% Y9 h" L
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speed ;; the speed of the turtle' I* i) [" M, K; L% b7 I
up-car? ;; true if the turtle moves downwards and false if it moves to the right9 b7 O$ K2 W* F/ H. i. q7 x
wait-time ;; the amount of time since the last time a turtle has moved
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4 l3 i# C4 h. d9 i$ lpatches-own
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intersection? ;; true if the patch is at the intersection of two roads3 I9 v2 ]2 O l- i8 M2 x
green-light-up? ;; true if the green light is above the intersection. otherwise, false.. T7 y5 j- \- u
;; false for a non-intersection patches.& Y0 O7 d, ~) v/ h f) R
my-row ;; the row of the intersection counting from the upper left corner of the
/ h% ]9 ^2 S A/ F5 z& k ;; world. -1 for non-intersection patches.& B, J* Z- Q3 N3 t! G7 L
my-column ;; the column of the intersection counting from the upper left corner of the
. ^. W+ T% p% g4 C. J. z" Z k7 v" w$ L# ~ ;; world. -1 for non-intersection patches.7 g% }- P$ H& t/ s4 M
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
) E. I4 h/ |) ?4 B" s; H8 K auto? ;; whether or not this intersection will switch automatically.0 O( ?+ \# c8 r0 ] \% T- h
;; false for non-intersection patches.. `+ k& x6 N' Q! V ?
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9 F8 L! L/ V1 G$ `) r) S- m;;;;;;;;;;;;;;;;;;;;;;
2 [+ D3 q7 b/ x0 {;; Setup Procedures ;;* k) @0 Y7 }& x/ t+ _
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;; Initialize the display by giving the global and patch variables initial values.0 M+ c# p) \$ B4 c: f
;; Create num-cars of turtles if there are enough road patches for one turtle to
6 ?( V6 B: S: a0 F+ `;; be created per road patch. Set up the plots.
4 ?3 }, g7 B7 u( f/ a; E' ^# mto setup1 q! m. o$ ~8 Y7 ?
ca
& @6 b9 w% D. e f ` setup-globals
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;; First we ask the patches to draw themselves and set up a few variables& ^) Y7 ~( A. M+ g
setup-patches
' }5 R% G; c$ y" \2 Y make-current one-of intersections
1 b; H" D6 t3 p# i* B2 y label-current3 {: T) r( V5 v. t& z; M# C5 s" Z# q
0 b! k% B y) [8 B2 ?8 N set-default-shape turtles "car"; f, l# y& @) W+ }) R! q$ {
' {: F8 X: ?! j3 q- N" N if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "6 T$ f% w. ?9 k+ m0 g# c' G
"road. Either increase the amount of roads "
$ I/ e* D9 O& x% |2 I N0 x "by increasing the GRID-SIZE-X or "' `2 y1 V; V3 R& ^' ]' Q( ]% g. O' i
"GRID-SIZE-Y sliders, or decrease the "5 X$ t, E, R9 f$ z. l/ m/ g
"number of cars by lowering the NUMBER slider.\n"$ V5 z( b* F2 h- t4 }/ k4 ~
"The setup has stopped.")! v- K) J$ }) S& s4 ^) S+ Z
stop7 m" |4 M5 |4 Y; Y5 H7 b- J
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, w9 f+ |; Q1 K7 N. v+ m ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color$ x1 u8 X% f- u2 J. ^( @+ Q; |
crt num-cars8 K" }! z4 @0 H+ z; T& y
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setup-cars
7 @) ?. C0 V R( K0 I( @" D( J set-car-color; D5 {3 i2 Q; N* l5 f* V8 k, y
record-data
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;; give the turtles an initial speed
D3 |: Q% S) v, d8 K' @8 P ask turtles [ set-car-speed ]
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$ o: U! y i! o: P u reset-ticks
1 ~5 _2 j, R) d: N5 K4 M, j0 I/ B( S/ nend1 H9 D3 A2 q3 {$ v9 X* i
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;; Initialize the global variables to appropriate values3 D% V k1 n* b( a! `5 v1 Y9 k2 p. O
to setup-globals/ g7 N7 O4 M( X2 S& T! b9 j
set current-light nobody ;; just for now, since there are no lights yet& @) J3 R$ C1 @
set phase 0
5 [0 c) T$ s( M8 U( u set num-cars-stopped 05 l! |& E! H5 |( t& T* Z
set grid-x-inc world-width / grid-size-x
" a' ]+ {7 k1 e+ P; p* L9 k/ t; h 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 boundary0 o1 q. f- ?. r! G
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
; J* t5 B, v9 o* J;; and initialize the traffic lights to one setting
3 x$ D1 Z, R! ?+ cto setup-patches
7 y5 O! K$ U' [. q- A ;; initialize the patch-owned variables and color the patches to a base-color, }; r3 X! `! w1 Z
ask patches
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set intersection? false
. r* O& v5 g) M' }$ x+ z set auto? false7 a$ I4 h$ p! H, t; K
set green-light-up? true$ R: z' i( I3 x [6 B
set my-row -1
, p# f1 p$ i5 f: F+ \6 @ set my-column -1, d4 i2 X: `; V) C
set my-phase -1
7 o6 o' S" ~$ c: m7 {4 Q set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets$ v* g* S/ |" [2 c" M
set roads patches with
' P" R8 i# r( l$ e" d% Z$ T" o [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or$ \0 @ e' ]* x6 N) [! v3 {
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 k/ b8 N4 ^/ W* f2 E
set intersections roads with
5 R; ?( E9 {* Q" [9 |' N8 c [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
/ F& \4 T, { P D (floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 t2 a% {6 n* D+ O
9 \1 O& d8 V; C o ask roads [ set pcolor white ]* @& L3 X% r( h& L
setup-intersections
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; m+ G5 T; ^# D9 V其中定义道路的句子,如下所示,是什么意思啊?2 a7 R2 C4 P( a! o$ v8 ^' k
set roads patches with' V6 e% w8 d& o/ T P' D5 f) [
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ C' G0 w# a2 G \& x (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 a2 q8 L, _% }: P0 M4 F" d1 X3 H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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