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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 b; ]& P6 X* U4 @5 E. knetlogo自带的social science--traffic grid这一例子当中,
& Q y; i n* S/ V$ s/ G6 U! ]globals
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+ g! @3 W* Y* Z. P grid-x-inc ;; the amount of patches in between two roads in the x direction
" d H+ a0 G! u1 `* v+ G" y& R grid-y-inc ;; the amount of patches in between two roads in the y direction; l0 o( w1 T% G0 |8 N5 u
acceleration ;; the constant that controls how much a car speeds up or slows down by if
* z8 I; e& I$ T$ a ;; it is to accelerate or decelerate$ H8 g e. ^3 n
phase ;; keeps track of the phase! Y s5 Y3 T' _( G+ ^
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
$ d) l4 k* ^1 Y5 Q. u; u2 X( ` current-light ;; the currently selected light
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5 u# Z+ [* \6 g ;; patch agentsets/ x& \' E2 s8 x4 y3 i, K0 L8 l8 Q9 P
intersections ;; agentset containing the patches that are intersections
2 T& _' Y' D4 Q' i* U6 M a: t; ` roads ;; agentset containing the patches that are roads
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/ w4 z! K8 v2 Nturtles-own
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; l- q7 q+ `( f8 f' h( {0 S speed ;; the speed of the turtle
7 c$ a, Y6 {; d7 n) e- j up-car? ;; true if the turtle moves downwards and false if it moves to the right
; ]' ?. `; j9 h. A% N& n) b wait-time ;; the amount of time since the last time a turtle has moved# w" H% d! a ?6 m
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3 W/ u; _4 b; D8 qpatches-own* _4 U# [+ A7 W' L
[
2 K4 t. s3 t( Q$ x8 c' _. S8 S& A intersection? ;; true if the patch is at the intersection of two roads! U2 J* K$ _8 W9 `* j+ u
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
& ]4 y _+ Z4 ?: e ;; false for a non-intersection patches.
8 q" I* V- o4 @# x( H2 x my-row ;; the row of the intersection counting from the upper left corner of the
# U4 D$ R& P/ e/ x/ u0 W& @+ f ;; world. -1 for non-intersection patches.
7 ?4 T7 N6 g0 p my-column ;; the column of the intersection counting from the upper left corner of the
- y: u8 c7 j' L! r ;; world. -1 for non-intersection patches.
2 a1 d1 T) L( Y9 L my-phase ;; the phase for the intersection. -1 for non-intersection patches.4 d: o3 K z8 a( K" `' [7 O
auto? ;; whether or not this intersection will switch automatically.& t8 I' F' u) @* B: j
;; false for non-intersection patches.! u5 |& {$ c2 l* w
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, f, A2 S- G) c/ f3 E& l7 K/ G1 W;;;;;;;;;;;;;;;;;;;;;;) a( B0 m1 x' ]
;; Setup Procedures ;;- ^. } w6 f, F' w
;;;;;;;;;;;;;;;;;;;;;;8 b2 V" C6 M3 I6 a9 c5 Q) @
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;; Initialize the display by giving the global and patch variables initial values.3 f u9 h, y' |' u3 W
;; Create num-cars of turtles if there are enough road patches for one turtle to
2 J; T8 B$ [8 @* b$ \;; be created per road patch. Set up the plots.
6 F5 I0 A- z7 R4 v$ E4 hto setup
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- V1 P5 Q6 z+ x: |; W setup-globals% X" G5 F8 M$ ?2 P# I
7 [: X# w' G- [- G1 n. X ;; First we ask the patches to draw themselves and set up a few variables# k, h: i# _, Z
setup-patches$ ?9 ~: A( J- N& f
make-current one-of intersections
+ H* x7 e3 V( P8 d( N label-current& E2 }+ a" c1 l
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set-default-shape turtles "car"
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if (num-cars > count roads)3 u% S M, K+ t7 ^
[
% e _" a" k: `6 Y0 _# S$ { user-message (word "There are too many cars for the amount of "# z1 t9 j' E7 ^8 r6 J
"road. Either increase the amount of roads "# Y+ @5 Z, ?4 @
"by increasing the GRID-SIZE-X or "
' Q, E/ k& o8 s& I "GRID-SIZE-Y sliders, or decrease the "
% ] }2 c7 r9 g `% n* f! M "number of cars by lowering the NUMBER slider.\n"- b9 @ t! I1 |: w7 Y2 }( B$ V* D; m6 t
"The setup has stopped.")/ f$ ?( G) X) a" m( X3 E
stop0 z1 A' ]3 c7 ^; A* ~# n: Q. D$ |+ j
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
9 F0 ?( }( y* {. d+ m crt num-cars
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setup-cars# r) [# J9 }( U
set-car-color
2 L$ Z( O! b& v' h- _* }: u, |( p& | record-data3 I1 W( H2 ^0 h/ [. k- L
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;; give the turtles an initial speed2 V$ D j3 C5 Z% z$ L
ask turtles [ set-car-speed ]
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reset-ticks2 G) E; i' G9 o: L
end6 T$ t: b6 z# \2 b. d' n0 T
+ G9 E( K% [9 o9 M;; Initialize the global variables to appropriate values/ p8 i" ?* Q8 f9 V# `. } ]
to setup-globals
$ a" S6 \$ u1 {/ ^6 M/ L9 S set current-light nobody ;; just for now, since there are no lights yet) p9 e: l0 x" ]( x1 M
set phase 0
) p X8 |# t0 L6 e* V set num-cars-stopped 05 Q |, r' x8 `; B: ^, ~& x
set grid-x-inc world-width / grid-size-x/ ?3 V2 n) ?) K) L8 V$ L4 a4 Y
set grid-y-inc world-height / grid-size-y
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1 |( e) G* E9 N& w& N, K ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary: g6 ?* f/ K% I3 `* g
set acceleration 0.099
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: o" u, A' B5 c3 C R) D F;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
$ b2 |( K& h" e0 P$ v6 V& ?;; and initialize the traffic lights to one setting5 }: j* m' y2 e: W
to setup-patches
, u2 |% X% T$ K- [+ I ;; initialize the patch-owned variables and color the patches to a base-color
" m- v3 @# t; M5 G* E* k4 L* I ask patches6 [3 Q5 _' _9 V. q: ~7 i) V
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set intersection? false. P) S1 ]* P% }- Q
set auto? false `8 }9 ^1 W! @; S! Y; @ W
set green-light-up? true
$ `. m: a H6 D% O, ~ set my-row -1 U! [. V3 F4 s) I
set my-column -1
, q" s. e# g# K5 o5 c0 {& ]- i4 ? set my-phase -1
8 t% @3 x# q; Y9 b7 Y set pcolor brown + 3& ~; @+ c: v$ D* g" }4 x
]
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;; initialize the global variables that hold patch agentsets0 f; }- G0 c- H O; `
set roads patches with
$ [+ K% }8 X0 x, T( B [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 Y, s6 D0 q z6 p7 A
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 P7 q4 Y4 }- I6 d5 Q
set intersections roads with1 B0 [7 k3 z ?+ A3 f- p4 X1 R3 W
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and- g7 L6 F2 n" Y R( V! P' Z2 J
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]* v* ]% G& n4 ?( G$ J8 M% x
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ask roads [ set pcolor white ]
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/ f- O7 [, `- i8 e3 _! kend
l3 q8 c: v1 S: O; Q) T其中定义道路的句子,如下所示,是什么意思啊?- X. f+ C5 g" L7 p& f
set roads patches with
/ J5 ~) p" o4 E [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# d3 z9 I ?3 C! {, a* a (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; N: o8 [2 A/ \+ ~6 f/ L+ 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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