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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。. H1 O, b0 l$ C: `# C/ F- n
netlogo自带的social science--traffic grid这一例子当中,
8 S' ^9 v4 {1 D. c$ cglobals2 i3 R' f9 J8 b9 L9 B# f+ i
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- V3 D5 r8 u8 x& [7 d grid-x-inc ;; the amount of patches in between two roads in the x direction
( [8 |% e i0 J9 x' Q grid-y-inc ;; the amount of patches in between two roads in the y direction, B6 X" n ]3 g5 m0 @8 }+ _
acceleration ;; the constant that controls how much a car speeds up or slows down by if
! t+ R! z9 E. c+ v6 b; a: H ;; it is to accelerate or decelerate4 M$ z, g& e9 a* ?
phase ;; keeps track of the phase
; X8 B0 a F0 l+ G+ m num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure7 t6 n1 b) `0 }8 |8 n0 K" S
current-light ;; the currently selected light1 u7 ?8 C! e# x# {- v& }
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;; patch agentsets
& \& I1 G1 y: W r+ D. E intersections ;; agentset containing the patches that are intersections
% j' A0 z! K2 d* S; S1 ?; E9 v9 X& ] roads ;; agentset containing the patches that are roads5 S7 l/ c7 i& `! Z; |' V; J& u% V
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turtles-own, t1 a9 T( ~) ]+ r8 z
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speed ;; the speed of the turtle1 a2 y7 n' Q$ Z# p1 g' }
up-car? ;; true if the turtle moves downwards and false if it moves to the right
: D9 Z, n: \- ^4 Z wait-time ;; the amount of time since the last time a turtle has moved# w- g+ F, n) k
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; O7 O( B# v o: f' b$ ^' Vpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
6 v) S7 j$ _, k& h! R2 @' N green-light-up? ;; true if the green light is above the intersection. otherwise, false.
y9 I" D4 a9 F( T ;; false for a non-intersection patches.
% }! K8 P: ~9 D, L! _! K my-row ;; the row of the intersection counting from the upper left corner of the" b: C& u. q* y1 t2 e
;; world. -1 for non-intersection patches.7 P" h% O. ?" s8 H
my-column ;; the column of the intersection counting from the upper left corner of the; ? M: t$ c9 q1 m$ q; t# t
;; world. -1 for non-intersection patches.9 p1 x* g* L# {( w" k& s
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
t3 ~/ _( s7 S2 O, A auto? ;; whether or not this intersection will switch automatically.- f6 v0 d( H" v+ @7 [
;; false for non-intersection patches.
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: o# l5 F x" k: c% a, G;;;;;;;;;;;;;;;;;;;;;;' p) \5 [3 [. ~& n
;; Setup Procedures ;;- t9 g+ I# d: m0 W6 g, U
;;;;;;;;;;;;;;;;;;;;;;# m m! u" T7 q) _
* i0 g! d$ `1 H% Y;; Initialize the display by giving the global and patch variables initial values.8 ?# ?7 n) i- q8 Z+ J# L
;; Create num-cars of turtles if there are enough road patches for one turtle to+ {! ^% U0 m1 H# ] S0 r: y$ q
;; be created per road patch. Set up the plots.
k$ \; X7 `& t% eto setup: w9 R* c# Y; G0 H! |
ca
) Z+ g9 o6 k2 W) `9 _* v setup-globals# W; C2 `( O8 n* V% m0 _
& k% v) V5 M+ W4 O. X( t ;; First we ask the patches to draw themselves and set up a few variables
Q: U ?/ d7 S" v setup-patches
1 E& J! U/ o6 h) y9 u make-current one-of intersections
$ B% _" x$ D" g) m9 v3 a label-current
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set-default-shape turtles "car"/ F9 ?7 O7 S+ u' g/ s
, p3 ]2 o" j, ^1 U w# v if (num-cars > count roads)$ f! V/ \! Q& S, M
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user-message (word "There are too many cars for the amount of "" P0 f+ _4 Z. o2 G F3 a+ j
"road. Either increase the amount of roads "
, ~4 M, B: g% f5 _* a* {* s- E9 Z "by increasing the GRID-SIZE-X or " W" a, b! k, g
"GRID-SIZE-Y sliders, or decrease the "3 W% M9 k# t1 \; C& @
"number of cars by lowering the NUMBER slider.\n", R5 X" L; I4 H& [
"The setup has stopped.")3 f% z' Z% @1 @) Q+ K" C7 b
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
& m: @8 @4 Y" u9 H2 c: j7 I# I z crt num-cars
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# Y) s/ j' }! s) J/ A$ A setup-cars
2 _. R) Z' H( E: I# P0 c set-car-color
; b a" a- m8 @& Y) d record-data+ G7 e8 U4 f2 B' ]0 j
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;; give the turtles an initial speed
3 e) W) i9 X+ P2 O; d ask turtles [ set-car-speed ]; h' B2 ^8 N o! R
2 S: o; V: l( b1 y" W; t reset-ticks: Z2 _6 J( Y- D$ |$ ~
end
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) Z1 n8 O4 H( y6 r/ e: n( Z' m;; Initialize the global variables to appropriate values
6 U2 I% d/ r) j4 I' W6 E% hto setup-globals# ]3 O7 ]4 B+ ]" Q3 s, r
set current-light nobody ;; just for now, since there are no lights yet
. B; ~7 w- e8 m set phase 0
, b( { U# h1 G set num-cars-stopped 0
5 j3 L3 U, [, u8 | [* c set grid-x-inc world-width / grid-size-x& L9 c% `/ f1 k/ i- f4 a
set grid-y-inc world-height / grid-size-y
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; O- E" z% r1 _5 O0 f7 Y N( h+ c ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
( ?" Z* P1 k( R2 t5 R' N& L set acceleration 0.099, y8 z# V5 I# K
end
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; B- A. g" |8 A: @5 M& f;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
) V! j# i& h/ b# ?;; and initialize the traffic lights to one setting5 a. P8 x: C$ W- J" l, H
to setup-patches
& y7 ?" j) E3 q' q6 r ;; initialize the patch-owned variables and color the patches to a base-color
" ?: G. d% O* E, ^0 w ask patches
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set intersection? false
0 j7 a& x# }% l5 R1 [) m. D5 k set auto? false. F, E8 Y& B) {: i: `, Z& w% j
set green-light-up? true# e) J) k0 S- S
set my-row -1; y' h$ M8 t+ a; @
set my-column -1" Z: _: X0 i# \
set my-phase -16 M, q/ X _/ H
set pcolor brown + 34 d$ y _$ _, S7 i# T. l+ x& q
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;; initialize the global variables that hold patch agentsets) V9 |3 ]9 I* Y# z3 O9 Q% q6 D( F; A: t( k
set roads patches with
' t6 o2 }) R) O O" I6 n+ O' ]) x: S [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 q' y0 m# t7 Y/ z- m (floor((pycor + max-pycor) mod grid-y-inc) = 0)]' R+ Z) y. _' I. V# ^
set intersections roads with9 r, I1 T4 x9 |% t* [
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and8 H E1 v: A; \1 a
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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: R w' Z7 n& s* k ask roads [ set pcolor white ]" P& O! C) n: g) e3 o- i2 z) u6 z0 J4 I! [
setup-intersections
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: N. z' o! F6 Q/ i1 M9 m8 |其中定义道路的句子,如下所示,是什么意思啊?+ i: F* H4 k0 t& L
set roads patches with* k+ p7 E0 z7 l5 r6 E7 q
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# j" p) G3 N. X! C- g (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: {! Z% ~& v' b _0 d {) ^
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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