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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。6 w. [& y9 J6 C
netlogo自带的social science--traffic grid这一例子当中,
% K9 o1 S" ~3 t' {+ `* eglobals
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) Z4 ~, k _9 `: b4 F; \( q# w8 N grid-x-inc ;; the amount of patches in between two roads in the x direction2 m; a9 D/ x& [# K- l. C6 B
grid-y-inc ;; the amount of patches in between two roads in the y direction" l; i n# f: e5 ?
acceleration ;; the constant that controls how much a car speeds up or slows down by if2 I9 g" f% R$ J0 Q9 Z. U
;; it is to accelerate or decelerate% R4 L3 @9 C. D5 P6 D8 y( U3 U0 S
phase ;; keeps track of the phase
5 S3 ~: U0 x; d3 c! ]% T9 l6 E num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
) z6 g% J! s6 q; ]: Q+ j" J current-light ;; the currently selected light
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" F& X f/ b+ q+ [ ;; patch agentsets4 Q6 b5 v$ `1 U8 f* w: y9 u+ h
intersections ;; agentset containing the patches that are intersections
( R0 m$ u0 w8 X; ?% H* B7 [" u roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle4 v, a" i1 o' _* z% A
up-car? ;; true if the turtle moves downwards and false if it moves to the right
; j/ z+ r0 P. c" Q; @ wait-time ;; the amount of time since the last time a turtle has moved9 h& L* ~% X: u
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7 k2 ~6 ?8 B' e) m! W" P" E' w# apatches-own
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intersection? ;; true if the patch is at the intersection of two roads3 ~3 t; d E, _* m% i3 b
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
$ v9 E" z& U; m0 y* A j; z h) u ;; false for a non-intersection patches.: S; t8 B/ X' Q. D
my-row ;; the row of the intersection counting from the upper left corner of the
5 g' Q8 s2 T& Y; x0 j0 P5 E; w ;; world. -1 for non-intersection patches.
" G6 M' ]* g8 o2 d3 [3 o" m my-column ;; the column of the intersection counting from the upper left corner of the
4 ^ |4 n# c" W: _5 D4 N0 \4 x( _+ z ;; world. -1 for non-intersection patches.
' S3 @- F N$ Y1 D9 t my-phase ;; the phase for the intersection. -1 for non-intersection patches. }. R4 w* X! E# ^; w
auto? ;; whether or not this intersection will switch automatically.
; d" @) f! \) r0 T8 \ ;; false for non-intersection patches.& |% v) Y0 t* B2 e/ A% Z- ~6 [
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;;;;;;;;;;;;;;;;;;;;;;" }( }( J9 V. Y! r% i" W m; y/ g; Y
;; Setup Procedures ;;
$ J, `% n) j4 w0 B+ E: z6 U+ m;;;;;;;;;;;;;;;;;;;;;;6 K# s6 [. c; L
' D. f3 a) _5 ]) ^;; Initialize the display by giving the global and patch variables initial values.% O. W5 {7 @! |9 B) }% z+ J1 {4 ?
;; Create num-cars of turtles if there are enough road patches for one turtle to. s5 F+ s4 P- z: J
;; be created per road patch. Set up the plots.5 I; w7 k- m# ~: |& B
to setup
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' X* Z- S; j. v$ A1 q) @& G setup-globals4 S5 ?# V$ f- }+ @
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;; First we ask the patches to draw themselves and set up a few variables$ T- s/ O1 R, w5 A
setup-patches
! F$ ], c" j* \1 f8 w make-current one-of intersections
% E; Y r& l7 v label-current
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set-default-shape turtles "car"& D/ D& B/ C$ g" d$ D7 S
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if (num-cars > count roads)
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& j) w4 r' y+ y9 j$ V+ a3 a& C user-message (word "There are too many cars for the amount of "2 b3 C" G' c0 z8 R8 H9 ^; `
"road. Either increase the amount of roads "
) n/ k# |4 M, ?1 i "by increasing the GRID-SIZE-X or "9 _* M" o a' @& _
"GRID-SIZE-Y sliders, or decrease the "' f# l4 W$ Y( n# t
"number of cars by lowering the NUMBER slider.\n"1 N# N4 M9 z% P% U! Z K7 |; s
"The setup has stopped.")
+ S( e2 G) G5 a7 X9 g stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color: {) l7 c3 ~/ `' m
crt num-cars
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: K! I" l4 v4 }0 y5 @' v; m. M. P- Q setup-cars
6 p5 Y8 v, i3 l& V8 q set-car-color
C. [: k, o7 c$ U+ b. G record-data
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;; give the turtles an initial speed
) L- a6 g# Z) i; ^ ask turtles [ set-car-speed ]
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- b. }! e6 y. {! i j reset-ticks
8 q9 v3 c h4 N/ m) ~1 W# d* S: ~ d% Cend
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;; Initialize the global variables to appropriate values
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5 \4 I% r: A' `+ [. r1 m1 B0 C set current-light nobody ;; just for now, since there are no lights yet. b) L' _1 `0 k" M
set phase 05 ^7 _4 C5 h3 n* F( _& n( j* G! i2 m
set num-cars-stopped 03 f" q# K, {0 }! `
set grid-x-inc world-width / grid-size-x
9 F/ ^7 n" G* D set grid-y-inc world-height / grid-size-y- U( M( @" I$ ?& d! h
8 m# K- C1 s! |' A" g# L# l ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary4 t; q+ ?: |8 b/ M- A5 ^
set acceleration 0.099
6 j$ I: O8 Q/ x, \2 U8 X7 nend
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( ~; ?! F! E. g' G* |;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
& l& {. S2 v: i6 J+ n) l& A3 t/ k;; and initialize the traffic lights to one setting% `3 V* y, v$ d7 [
to setup-patches
% J( s) f& s% { ;; initialize the patch-owned variables and color the patches to a base-color7 {) c; x; F# g. ^6 a
ask patches" i8 U( r+ F$ q7 C* s) ?& [ O
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set intersection? false: w- a! v6 x- O D& M w" S
set auto? false: D( q; x3 o" c2 Y5 P5 d
set green-light-up? true
) f1 N. G! D. k7 R% q( Y2 _6 X set my-row -15 n) Y E- O, j) a8 D
set my-column -1+ e+ y; M, Z( W5 D) V+ r. R
set my-phase -1+ I9 G* Q9 M4 z5 @
set pcolor brown + 3
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! I7 ]! N# L/ o& ^2 ]2 b ;; initialize the global variables that hold patch agentsets
5 t& V/ Y& m# r3 d set roads patches with, c6 i9 P# r, ~
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
) N4 G' n* ?; }2 Y0 W. s* W (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
- m! W8 o7 r- ~7 @ set intersections roads with
( F$ K$ B8 ~) c( { [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
4 _2 V& \; M3 }6 H9 O; i& s F (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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其中定义道路的句子,如下所示,是什么意思啊?
: J2 Q/ a3 K2 @" G5 y9 i% K set roads patches with; d* }7 A! D; O
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 m2 k. m. E* G- R i
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
x# k4 A3 p9 f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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