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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。" T8 t, T% i( o
netlogo自带的social science--traffic grid这一例子当中,! ?8 C/ N, a& ~8 j( b; T* ?
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
M: M5 Z1 z; Y& ?$ M& `9 P9 |! m grid-y-inc ;; the amount of patches in between two roads in the y direction' r! x- q7 ]& K5 o; G& [
acceleration ;; the constant that controls how much a car speeds up or slows down by if8 p1 ^7 W; |8 x* ~8 T; V0 h: ^" P
;; it is to accelerate or decelerate$ X- e+ P# c) d
phase ;; keeps track of the phase
' v' W. r4 F1 I: q0 J' ~ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure3 c& t( o1 l: {
current-light ;; the currently selected light
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;; patch agentsets- w! b6 S, t' j: j. x; `6 Z$ M
intersections ;; agentset containing the patches that are intersections' r) i. v# K, h& D
roads ;; agentset containing the patches that are roads% T2 r8 r3 G( c. c! f: Q
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turtles-own
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speed ;; the speed of the turtle
1 X; E: j' j+ ^# k& Y up-car? ;; true if the turtle moves downwards and false if it moves to the right V8 f! p3 p& M8 d0 x
wait-time ;; the amount of time since the last time a turtle has moved
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5 U* U4 A) k9 ]) B) s: n! Q; wpatches-own. X0 C1 N r7 _
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% }5 b2 I+ Z, j! q intersection? ;; true if the patch is at the intersection of two roads; I& O: ^9 X7 q/ h9 a/ I
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
) c1 `# q5 F4 f& l& N ;; false for a non-intersection patches.
- Y- Z8 e" Y( l5 x) J. [ my-row ;; the row of the intersection counting from the upper left corner of the3 A8 M9 @$ e6 q3 {* t
;; world. -1 for non-intersection patches.
' x; H0 j1 `2 U7 T3 {, e: E my-column ;; the column of the intersection counting from the upper left corner of the4 m+ e8 f$ Q" H" L; N& N5 w
;; world. -1 for non-intersection patches.
+ R3 s% q3 Q: w; r% v; M/ Q my-phase ;; the phase for the intersection. -1 for non-intersection patches.
- W' R+ t% A" @8 `1 H# u3 a auto? ;; whether or not this intersection will switch automatically.8 K; [9 @+ I1 P+ [" x6 n4 e. d
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
0 Q6 d5 ]' _3 P2 z" m* w. M! t;; Setup Procedures ;;" r5 W9 R; u& y6 T/ ~) U6 e
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;; Initialize the display by giving the global and patch variables initial values.
( m, W' V! Y1 g! M z& ^9 c;; Create num-cars of turtles if there are enough road patches for one turtle to
) u3 X1 P* C9 D# a1 Z" H;; be created per road patch. Set up the plots.' p ?$ a* Z5 k# W9 j/ {0 I
to setup
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0 k/ k. p/ S8 X; @; ~ g setup-globals" ?8 H1 q7 M: v; m+ f0 R5 P
5 V2 j) o1 i" Q' O9 ^2 g ;; First we ask the patches to draw themselves and set up a few variables
/ j5 t# u. x: M setup-patches, _- N4 [1 L4 }6 L* e ]
make-current one-of intersections
! O8 z; @, S% _- e4 r label-current
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( k) V' U1 v. B0 w set-default-shape turtles "car"
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6 y3 q$ I2 v/ |* _ if (num-cars > count roads)8 r0 y8 \6 ?8 i5 X" t9 B8 l+ F/ h. V
[
0 W, L2 ^% W% }, L3 a user-message (word "There are too many cars for the amount of "
7 [$ s4 J3 j: a$ @. v7 A/ H "road. Either increase the amount of roads "
! l. k/ L D* L4 N) l' U8 a. V "by increasing the GRID-SIZE-X or "
$ |, l* O# d& `: ~/ O$ q$ v1 F "GRID-SIZE-Y sliders, or decrease the "% I; m, j3 _7 Z, H' s% ^
"number of cars by lowering the NUMBER slider.\n"9 c3 b& z! q/ r: S3 A
"The setup has stopped.")6 Y6 c$ b! ^4 U. A
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color5 U# Y/ C: c! G! s8 T3 U
crt num-cars6 j) n% e7 I4 q% {/ u3 M
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( b) t/ k" r& K% Q& X9 m setup-cars
" n8 `. p$ j7 J) A$ L set-car-color
, t% k# |+ c3 P' J record-data9 v: m+ k+ E7 ]! }9 o& S y
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;; give the turtles an initial speed( \- c, _5 Y9 q Y& _: f
ask turtles [ set-car-speed ]
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reset-ticks. G3 [3 u1 X' M7 V% U& |) r
end
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- b5 \! w/ c; Z2 ?;; Initialize the global variables to appropriate values
& p1 ^' q% l- z# }) kto setup-globals
: b5 }) v/ ?# N: ]) `, e! Y set current-light nobody ;; just for now, since there are no lights yet
/ f) S( {; o" V set phase 01 x8 ]9 O$ p) S' s9 {9 r4 j! O
set num-cars-stopped 0" m% B3 e* F A" K- o8 v6 T
set grid-x-inc world-width / grid-size-x
2 I3 H1 z- c$ W3 s) g: h set grid-y-inc world-height / grid-size-y4 q/ e1 G4 u2 r! }* K" D* T
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
8 F' x t# J* H5 e7 m set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,% _& d, a% ^3 ~
;; and initialize the traffic lights to one setting
- v4 i! x- d j* O# r6 V- fto setup-patches
: c; ~1 a% @% | l ;; initialize the patch-owned variables and color the patches to a base-color
2 e$ z" \4 f; c% N" m R ask patches9 h, y$ ]4 X4 R1 [
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set intersection? false# ^- W& G: b5 B, e$ M. u- H, g; `
set auto? false
& Y" ?- o* i2 Z0 U; c# w! E set green-light-up? true, X; X+ M% z/ A# ~/ }$ l! f
set my-row -19 i0 l$ F& i T9 Y8 j+ I
set my-column -1
. |, C: L2 G. Z1 } c set my-phase -1
8 [5 X6 S9 C+ O& O" B" L set pcolor brown + 30 ^9 @0 t+ u, G
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;; initialize the global variables that hold patch agentsets# b+ n8 @( n8 q' X. [; v& k
set roads patches with
[9 Z: e8 { R; _ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 @6 A3 r! i+ K7 r; y2 f3 O4 J (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 L# g5 e* x8 F set intersections roads with0 B5 i% `6 s; y* E
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and1 u. |3 u b* J1 v/ Y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 L& ?5 J8 `. _. g
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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?
, f& q2 y( |) F# c set roads patches with; T. W8 a" L$ o& e# b
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' t$ L/ x- b& y# m8 W (floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 g- P( Q# x4 B3 A T) g7 J
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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