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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。( Q6 A" y4 R; Z3 r% o* N. |
netlogo自带的social science--traffic grid这一例子当中,
- Q1 @3 m, n I. @! ~; g+ pglobals/ {- a+ v$ G9 C& \
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grid-x-inc ;; the amount of patches in between two roads in the x direction
( O; \# S$ w' F3 } grid-y-inc ;; the amount of patches in between two roads in the y direction( Y0 Y: B& t( L- f, ], V# }
acceleration ;; the constant that controls how much a car speeds up or slows down by if
* `. L9 D2 k( p j7 W, ?) `" S4 u5 J ;; it is to accelerate or decelerate, A- W+ t! f, N4 x* M( z x
phase ;; keeps track of the phase$ C6 O- P& Q* o* _) V. E- _2 c7 j
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure7 `7 O( P/ M _
current-light ;; the currently selected light Z# v/ H# Z* y8 u
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;; patch agentsets
# ]- P) |7 t1 g' n; @" j intersections ;; agentset containing the patches that are intersections) s3 \- {2 ^& o% _4 ~% W
roads ;; agentset containing the patches that are roads
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+ p5 w C- |4 {! U- E2 v5 N$ s! @4 i& L
turtles-own
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speed ;; the speed of the turtle% c7 H# g' u7 z' n
up-car? ;; true if the turtle moves downwards and false if it moves to the right
7 a, u: H5 p; {7 q1 [ wait-time ;; the amount of time since the last time a turtle has moved* [; C. t% e9 }% v6 s7 ]# {. K
]
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patches-own& p3 o& Z |1 |% f; w
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intersection? ;; true if the patch is at the intersection of two roads) J' i) v/ B$ I8 r6 G" {) D9 S
green-light-up? ;; true if the green light is above the intersection. otherwise, false., V* O- z" L/ i5 u" z
;; false for a non-intersection patches.0 s0 j1 b! V5 O
my-row ;; the row of the intersection counting from the upper left corner of the4 s& Z- e9 ~( p7 w8 U* {1 T# F
;; world. -1 for non-intersection patches.
% W5 }( U8 Q. T3 Y! |' O my-column ;; the column of the intersection counting from the upper left corner of the6 b) ]4 n, H% t& ?9 Y
;; world. -1 for non-intersection patches.
8 k) t/ q. I# y- y! @6 K. g& e! E my-phase ;; the phase for the intersection. -1 for non-intersection patches.9 c# k! y9 `4 r: g8 f
auto? ;; whether or not this intersection will switch automatically.- H) C9 v/ G; }2 A
;; false for non-intersection patches.
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! s+ P7 l( t1 N' e' \9 K4 t- ~( {;;;;;;;;;;;;;;;;;;;;;;
6 X6 T. k2 I( _1 W h- a$ I;; Setup Procedures ;;
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$ _* f G) E9 e" T6 h, Q;; Initialize the display by giving the global and patch variables initial values. p% Y [8 T j% j4 G+ [- @
;; Create num-cars of turtles if there are enough road patches for one turtle to: z6 _: r: h5 Y4 l/ H7 w6 O0 H, F# _2 S
;; be created per road patch. Set up the plots.
5 S/ b9 _$ y7 w7 X1 K5 |to setup( [( f. Y7 P) i3 \1 w
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setup-globals9 L0 s4 g) n" y6 A
5 K( z; z7 o' p0 x6 @ ;; First we ask the patches to draw themselves and set up a few variables
) Y2 k# j) ?/ P1 K9 F- R+ j6 e setup-patches
) d6 ?- [5 C# f! q) t make-current one-of intersections7 r( c9 R4 ^ s( U8 u$ i
label-current
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- @8 T7 W+ w( G4 m* `- P set-default-shape turtles "car"6 w: I8 q+ e& W% Q
* ~" F6 B9 I$ E( D3 D if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
$ E) |! [) V- } ?) S+ J "road. Either increase the amount of roads "; C8 ~+ t5 g' @) P- k5 I
"by increasing the GRID-SIZE-X or "' e# B& S8 h2 @- K0 Z9 B* J/ d: `
"GRID-SIZE-Y sliders, or decrease the "
4 o: S- X: G- }* Q* R+ O, R "number of cars by lowering the NUMBER slider.\n"' {6 Z2 n2 \5 y. H6 B
"The setup has stopped.")
) x1 I' ]2 B% J G% ~3 U# T stop
% G0 b I2 {( E0 s ]
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! A+ ~9 M. ~! M; c( ] ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
' z1 l4 l3 a' s( W5 o+ H crt num-cars
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, X( S- r" O% f5 N7 V" w' w3 U9 b' M setup-cars
7 Y9 b8 d4 N% v7 m( q' ^1 M8 w set-car-color
' z% K9 F: I+ [3 ^6 w0 Y7 E record-data
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% G: d. P' J* z1 [ ;; give the turtles an initial speed
6 x& Q4 n8 f; X* J: C( ] k ask turtles [ set-car-speed ]
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2 X+ m- G$ o1 U, s* R# F reset-ticks
+ d4 |7 A, ^, g3 p, Dend
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;; Initialize the global variables to appropriate values K4 l2 o7 Z3 b# z
to setup-globals! b; c+ O( P2 X
set current-light nobody ;; just for now, since there are no lights yet$ z2 W5 H* r0 s& G1 g
set phase 0
; H! b q% n7 D5 R" Y set num-cars-stopped 0 e6 b, z7 W: k5 Z
set grid-x-inc world-width / grid-size-x' b* G7 Q; \2 i
set grid-y-inc world-height / grid-size-y4 m2 H, d6 P# r7 |
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
+ u$ k- g# n% R. n+ M set acceleration 0.099
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5 I' o1 T2 P6 U N1 B3 I;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
+ L9 f) W: v; n, C# c) y( j;; and initialize the traffic lights to one setting! q/ w. x: K# M' i$ R
to setup-patches
; l7 s# v: B0 P$ ?6 T, E ;; initialize the patch-owned variables and color the patches to a base-color
6 M h; x5 z7 f1 d: z1 y4 N. o9 W ask patches
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set intersection? false
; S& V1 b; d9 o" V7 K N set auto? false
5 e! C: A4 f* }1 D; g3 O5 M set green-light-up? true
# n7 L3 J4 b; y9 [ set my-row -19 p: C- r/ v. e" m% f
set my-column -1
" g) |1 M3 F6 c1 `& O set my-phase -11 y3 d9 z8 G( @: l8 l7 r
set pcolor brown + 3
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/ z6 i) n$ ~* h0 g( U& v; n9 F ;; initialize the global variables that hold patch agentsets/ }& C7 g% ~! u" E9 `0 s, ]" f& \
set roads patches with I( { w; X. [: l9 \/ T
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or$ @! u6 K& W! r& K# v
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 ~3 [9 N% Y. y
set intersections roads with0 \$ H( P% k! V& C
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
5 j$ C: d! m5 L- U5 _* m (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
& G/ b0 @7 f9 ~# U2 I setup-intersections2 I. d' e @$ l2 u" ]0 F2 k
end; ]# B6 ^2 S" Q1 d! R9 l
其中定义道路的句子,如下所示,是什么意思啊?
% p; [$ |$ |" E: R: r% {; Q* G* w set roads patches with
+ r& ~4 }9 I! f [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
) |7 J8 y0 Q v* E4 V (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: V. W3 n6 B- m L" i
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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