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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。, S1 M' C( }' ~$ |8 r( S; z7 `
netlogo自带的social science--traffic grid这一例子当中,
2 m5 w& I- P8 q1 J& j1 Qglobals
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9 S+ `, A4 i9 X9 K( f9 V' F grid-x-inc ;; the amount of patches in between two roads in the x direction
3 g+ K5 m2 r1 J4 F, Z# d- U/ F grid-y-inc ;; the amount of patches in between two roads in the y direction
0 j6 k8 d) r. O3 }+ ]7 M+ i0 C acceleration ;; the constant that controls how much a car speeds up or slows down by if
1 G, v( G# g& |5 ] ;; it is to accelerate or decelerate' j: L4 n; Y$ A* s9 K5 o, {
phase ;; keeps track of the phase
+ i f# K9 o) O2 Q6 q num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
; x W' p1 V% ^; {( W4 B! y current-light ;; the currently selected light5 b P8 t* j( Z: p. G
% j3 x, C+ Y- s* e B ;; patch agentsets
% ?1 A9 G9 {7 ]8 _# E) \2 { intersections ;; agentset containing the patches that are intersections4 `; S( s) g8 K( ~
roads ;; agentset containing the patches that are roads* M6 L& d+ S: X1 r4 ]( G
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turtles-own* X( j, A6 F$ o3 V% u# B2 `
[
; b5 b* U% l# u/ ?2 E0 G! T+ [ speed ;; the speed of the turtle
* a3 d5 i% l; Y' Z up-car? ;; true if the turtle moves downwards and false if it moves to the right g7 d; M$ I: A' A n+ X
wait-time ;; the amount of time since the last time a turtle has moved1 {% l+ F2 C" D6 ]( o8 v+ M
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( P3 |! X) ?& W$ H- Jpatches-own9 V$ r' y9 j: f$ b, a: ^
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intersection? ;; true if the patch is at the intersection of two roads
/ f# S7 _8 A0 p" a5 o% L0 e7 s+ p green-light-up? ;; true if the green light is above the intersection. otherwise, false.
& Q3 Z& h" O, r ^+ b ;; false for a non-intersection patches.3 G: Q6 \' X: Y' O7 ^
my-row ;; the row of the intersection counting from the upper left corner of the
, C# @3 G7 N6 w: @; ~8 j+ g ;; world. -1 for non-intersection patches.! L; l3 B" v4 t
my-column ;; the column of the intersection counting from the upper left corner of the y$ M+ I+ A3 Q9 s6 E
;; world. -1 for non-intersection patches.
( t' G% m( E) r$ e4 x' Q7 N my-phase ;; the phase for the intersection. -1 for non-intersection patches.% u& ^7 Y/ ~# ~$ w d0 Q
auto? ;; whether or not this intersection will switch automatically.
$ L6 o: g' X2 D: x v2 y ;; false for non-intersection patches.
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5 r z0 N4 Y; O) ?6 Q4 |;;;;;;;;;;;;;;;;;;;;;;
! Z O( A. z" M6 p5 |! W7 j0 s;; Setup Procedures ;;
/ @. x, i; y2 X! {7 b- c4 Z( H4 A;;;;;;;;;;;;;;;;;;;;;;0 j6 [: _/ j) B @( D% E
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;; Initialize the display by giving the global and patch variables initial values.
6 V9 L% U- t- Q; J: m;; Create num-cars of turtles if there are enough road patches for one turtle to$ C2 G2 N$ C( O$ \) s
;; be created per road patch. Set up the plots.
6 z: ?( o/ e' c* Z" Nto setup
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setup-globals
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. z) d( Y1 j* S8 Y, H ;; First we ask the patches to draw themselves and set up a few variables
( e6 Z _" }) e; c/ U6 y- w setup-patches
* e7 v% S' i6 ?; F- W! O9 O make-current one-of intersections
% U: c8 K6 k P _& a. } label-current7 P) u: A/ a, x5 s. ]
) N) T4 u! A% V: n: b+ W2 e1 z& d set-default-shape turtles "car"
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" U: `5 L! w8 U& \# m9 J if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
# K1 t/ P: M8 }$ }% q "road. Either increase the amount of roads "
2 b9 M, p' L1 R( ^# h" ?% r "by increasing the GRID-SIZE-X or "
) j6 {' v& \. T# l( G! Y* V "GRID-SIZE-Y sliders, or decrease the "! O& ^# q9 v0 b
"number of cars by lowering the NUMBER slider.\n") n, w3 P2 Y4 x8 _7 O
"The setup has stopped.")* v. W, U; t( a% p0 \' V
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
( o' q* W8 J8 X1 F6 D& B" u crt num-cars
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" s& r: Y* T$ a) R setup-cars1 e+ E6 Y- L) E
set-car-color/ |# N3 L, Q: R2 G8 W
record-data
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/ } ~3 n( ?$ \1 w* {$ L ;; give the turtles an initial speed) M: Z% K+ r0 l; k( J
ask turtles [ set-car-speed ]( s8 S# [' m6 M/ `1 t i
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reset-ticks$ e3 j# C2 o8 L1 M
end' V: ` {# q. e4 r
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;; Initialize the global variables to appropriate values. x6 T, S0 P) B. u2 H7 x, J. z, Z
to setup-globals
3 e; I" ~1 h- z8 t. L0 q. S% q set current-light nobody ;; just for now, since there are no lights yet
$ C8 O: t5 h* m set phase 0
+ d9 B, x. z: D4 |/ f7 H% h1 t set num-cars-stopped 07 [0 x, A) J: ^- q
set grid-x-inc world-width / grid-size-x) G5 ~) Z! k* Z+ G/ p$ k9 M+ z+ o
set grid-y-inc world-height / grid-size-y
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* [! k9 ?; r6 r ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
/ h/ v3 s5 L& O( [( t/ m. h. O C set acceleration 0.099" e- h& H0 i: G7 p l
end
% r: D( j9 @& a m8 c |: U
$ O$ t$ m0 S! [' S# };; Make the patches have appropriate colors, set up the roads and intersections agentsets,: A. ]2 I; p- {0 }8 `: g
;; and initialize the traffic lights to one setting0 k8 K! I' Y8 `8 ]9 I
to setup-patches, Z9 S1 \, G7 {
;; initialize the patch-owned variables and color the patches to a base-color
) ~& x* K( X! T D4 r; G. q ask patches
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set intersection? false
6 Z' c+ D; G% \6 X set auto? false
, x0 g* f0 h' r/ m set green-light-up? true8 E: K2 V! T/ w8 s1 D' p
set my-row -13 h A6 ~) z( f3 T# |2 t: J
set my-column -1
# T5 z2 z3 ?. J# V. U set my-phase -1( `1 y( B+ @1 }1 B1 T- S3 x
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets6 O: x7 a. h- @! ? L' N3 o
set roads patches with' S) f; c$ ?4 h
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or: B. Z" B- B3 ]1 C5 ~- {2 d" [" T8 {
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 k x' ?! } b y: ]/ z3 V
set intersections roads with
) h7 ^ J4 W9 a6 w8 D: F4 m* k7 H [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
" b4 t- o$ L- d% O4 C9 {, }- x! C; R (floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ J4 F& ]0 O8 _
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ask roads [ set pcolor white ]
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end
4 Z/ m3 s8 t9 Z/ e3 e) A其中定义道路的句子,如下所示,是什么意思啊?
- } k3 w- p- M B# x5 l set roads patches with0 b! f3 s& c1 p% p( b$ L
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 A4 l L( c5 x6 ?# l% e$ N2 o0 c, v (floor((pycor + max-pycor) mod grid-y-inc) = 0)], H3 p/ h& n- ^( \3 s
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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