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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。
( P! k# } Z# u; Gnetlogo自带的social science--traffic grid这一例子当中,
4 n7 Q4 W0 e+ y: g3 A# t* tglobals6 ~* N- e9 Q7 p2 ~$ W& K/ Q
[
1 F$ ]) P' {7 T% x" | grid-x-inc ;; the amount of patches in between two roads in the x direction. Y1 q3 a- n& G1 ]* N: c% S: k2 c
grid-y-inc ;; the amount of patches in between two roads in the y direction" F5 m: `- m% K B; B6 e
acceleration ;; the constant that controls how much a car speeds up or slows down by if
* O0 j/ Z. ~' x1 G' C: E ;; it is to accelerate or decelerate
6 f: f7 h5 S, J8 j- z* R phase ;; keeps track of the phase: p7 F1 @4 U, [; b7 \! T
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
/ V( i+ c4 L5 P4 \3 t/ ]+ \ current-light ;; the currently selected light2 ^) R; j, E6 T- n" Y0 h( t( g) @' G
2 u% f8 F/ M% t/ _: B" h ;; patch agentsets i1 |, B9 i5 Y, r) b# u
intersections ;; agentset containing the patches that are intersections) p# C2 _$ c. u$ ^+ @/ }2 x
roads ;; agentset containing the patches that are roads
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- H" G" I7 y; [turtles-own% S4 N( ]/ y# J8 R8 H4 k
[
/ R" e6 x; I( G- T& h speed ;; the speed of the turtle' n$ Z& K& j: a! o
up-car? ;; true if the turtle moves downwards and false if it moves to the right, `. e* y7 Z/ z& ~' I2 K: c; W
wait-time ;; the amount of time since the last time a turtle has moved
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; q( S q5 B/ Y2 N" Qpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
; o0 z: C: i# } green-light-up? ;; true if the green light is above the intersection. otherwise, false.
, j; }& }8 O% _( D4 E$ |% d ;; false for a non-intersection patches.
- k8 v" H. q4 W: O+ \ Z1 E my-row ;; the row of the intersection counting from the upper left corner of the
" @5 u* ]- `7 b N# G# _" [$ ^ ;; world. -1 for non-intersection patches.
# z) S! Q- |/ t; p r$ a my-column ;; the column of the intersection counting from the upper left corner of the+ [1 \! p8 _+ _2 O. A) p
;; world. -1 for non-intersection patches.
% e& B( \. j/ Z my-phase ;; the phase for the intersection. -1 for non-intersection patches.
/ h, n. z5 e9 V! `1 h$ G auto? ;; whether or not this intersection will switch automatically.
' X" b* ^1 o- ? ;; false for non-intersection patches.
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# [) e. ~1 n. _) R' d! u;;;;;;;;;;;;;;;;;;;;;;6 m/ C, H5 n; v3 o, G: x1 A
;; Setup Procedures ;;: z& h. e1 V9 H c# @
;;;;;;;;;;;;;;;;;;;;;;
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4 _3 T; ?2 e8 T1 h;; Initialize the display by giving the global and patch variables initial values.$ v1 A% O4 F% V
;; Create num-cars of turtles if there are enough road patches for one turtle to; G f0 v0 n* s* s6 I. _2 r2 c
;; be created per road patch. Set up the plots.; r: I% L: Z3 b) c
to setup1 w Z) j+ J* E
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables7 T9 A7 M" G; o5 i+ j
setup-patches
( A, M* k- X# b/ {9 D7 j make-current one-of intersections! ?9 J8 | L* d8 {9 x
label-current
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# q6 f% J6 L4 [/ }3 k" h set-default-shape turtles "car"
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/ k% k3 J% ?! F8 V1 f if (num-cars > count roads) |3 F0 ]: `: b
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user-message (word "There are too many cars for the amount of "
" v& t& {6 `1 h "road. Either increase the amount of roads "+ A4 Y* P0 G6 A2 b
"by increasing the GRID-SIZE-X or "3 H! i' z" G' J9 V8 g
"GRID-SIZE-Y sliders, or decrease the "
9 j- r' k h9 R1 e2 l& i "number of cars by lowering the NUMBER slider.\n"
2 g- ^' ~8 o* a* i! X' z. W3 j( m "The setup has stopped.")7 G! C* }: G) V: o& ?6 G
stop& u B7 p8 k- I' Z9 S' \
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9 p+ ^9 e" G% ~7 U ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color- n. W. J, W5 l
crt num-cars1 d8 X4 Z: z+ v- K
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setup-cars( b* ]3 ^4 V& b
set-car-color
( b9 R" L: s3 W record-data
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) A( U3 }/ m& c( m, G6 e ;; give the turtles an initial speed
o" K# ]: \! h3 |; N ask turtles [ set-car-speed ]" d* Z; u# |) r" p! [
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reset-ticks
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6 U- g$ J6 G, O& m, n; G;; Initialize the global variables to appropriate values
2 A% k% N) H% i r/ n1 gto setup-globals
2 j5 y0 e9 S# t set current-light nobody ;; just for now, since there are no lights yet
, Y, y! m! c" Y5 {0 P set phase 0" ^1 t% p) z0 W2 q
set num-cars-stopped 0# g5 q9 j; } a1 w( M4 N2 }
set grid-x-inc world-width / grid-size-x0 p2 R9 S- f5 l: I+ g# m+ `
set grid-y-inc world-height / grid-size-y
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* H# M6 X }- g+ d. m9 m ]0 K6 w* l ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary+ R$ @1 G- n( m8 r2 I- V, w
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,- H5 g1 E: h- F
;; and initialize the traffic lights to one setting% r# _: z: O; }9 K" b
to setup-patches* g. T5 z& _# m9 W6 S5 l
;; initialize the patch-owned variables and color the patches to a base-color6 m2 z) t: X- [& D) K) L- ?
ask patches
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' v x- f$ N) y' U+ X; l* Q set intersection? false& h' J+ }% P+ e
set auto? false/ y6 `6 W6 u7 `) ?* @6 ]2 m
set green-light-up? true
' B& s( {, q1 Y( h set my-row -1
6 ?' n7 ^% ~2 _$ E o' a& g set my-column -19 C; l/ R3 _+ n9 m3 e- n; r# s& e0 }
set my-phase -15 w$ s) i8 {+ _# b
set pcolor brown + 3" y# ^5 }& }/ c& X
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;; initialize the global variables that hold patch agentsets3 U' b; E# P* ^7 ^9 M2 @8 p( t
set roads patches with/ T# J9 V. N p, D$ a4 E8 e
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or- E. {; O3 r# Y5 C1 m0 D
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]" y/ A `' t$ ?1 i) {8 Z
set intersections roads with
3 g6 [' G. a* T+ }% Z* w [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
9 @" q+ U# V( M8 q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 v( ?$ m: A- A; ~: U% [ h
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ask roads [ set pcolor white ] j* |5 t/ S, k7 ^- i& q5 c
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?7 J, ^6 l0 k5 U0 [4 X
set roads patches with
/ i. C' n/ o3 }% X( u8 w [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# h+ \' f( p' R$ G9 a2 E2 t P (floor((pycor + max-pycor) mod grid-y-inc) = 0)]* i" Z, F* U" |! M& Z- G
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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