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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。4 F; T* R% @: q
netlogo自带的social science--traffic grid这一例子当中,
/ O( M M+ I1 d2 [3 s5 J6 I# wglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction6 g/ W! b$ r8 V2 |! m$ ?+ b% m
grid-y-inc ;; the amount of patches in between two roads in the y direction: P# n5 z6 Z( E: f, G4 H
acceleration ;; the constant that controls how much a car speeds up or slows down by if( G' o5 a* m, `5 w- y9 y) |
;; it is to accelerate or decelerate- r+ t" A) U6 K4 _6 e3 o c
phase ;; keeps track of the phase* l3 ?- X( V! c2 R \/ Y
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
- ]' ?+ U( p F5 |! ?6 y+ e current-light ;; the currently selected light' q2 l4 f( G& I" c
0 U" H- b, I. \, d P0 g ;; patch agentsets" K6 f2 G. V% q- V
intersections ;; agentset containing the patches that are intersections
4 X0 W$ k5 y7 t9 P8 Y roads ;; agentset containing the patches that are roads
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' G* k' ]# ^ Z, P- x, V* s9 Aturtles-own
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+ ]! S- |' v- n3 P; y speed ;; the speed of the turtle
! x+ t. e4 z N3 u. }3 P; Y up-car? ;; true if the turtle moves downwards and false if it moves to the right& c. V' _( r) O: i8 m7 ^) r7 M
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads/ `; c9 E X( \, Y9 c; q) Y
green-light-up? ;; true if the green light is above the intersection. otherwise, false.. e9 U9 O, ?6 z5 H# }) f
;; false for a non-intersection patches.
0 q N' ?+ h r my-row ;; the row of the intersection counting from the upper left corner of the
$ N: h" a! O) G8 M3 w. _6 Q3 ^7 L6 M3 u ;; world. -1 for non-intersection patches.! {0 E1 T5 a- K5 j3 `% ]& P, Y
my-column ;; the column of the intersection counting from the upper left corner of the
$ W5 m9 |0 X1 ]8 o) Q# D- G ;; world. -1 for non-intersection patches.! b- S; s2 b; H1 H# |3 K
my-phase ;; the phase for the intersection. -1 for non-intersection patches.8 v5 l( B1 G" w+ _' x4 @
auto? ;; whether or not this intersection will switch automatically./ h7 R( F, r6 f! Z! H. w
;; false for non-intersection patches.4 Q' q4 a) z7 ]$ k
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' L; S5 ^4 W9 R& r* _) Y;;;;;;;;;;;;;;;;;;;;;;
& e3 ]6 k" e% ?7 Z h;; Setup Procedures ;;4 ], X: Q7 Q b4 C* y) U
;;;;;;;;;;;;;;;;;;;;;;3 W0 X, c( W9 k! r7 ?7 } m
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;; Initialize the display by giving the global and patch variables initial values.+ g8 r6 u' E+ Z
;; Create num-cars of turtles if there are enough road patches for one turtle to& N% D3 r! ]: b5 }+ _" m' U# `
;; be created per road patch. Set up the plots.7 e5 G, [: x+ H8 w% {4 s+ n$ @" b/ t
to setup/ z6 E7 N9 |, J! _
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setup-globals! H# B1 v( ]+ @" p
: C% ]% B* Z7 _" w ;; First we ask the patches to draw themselves and set up a few variables
4 G) c# W) [) Q3 S. p- P2 A setup-patches
9 k$ u8 S, x3 Z make-current one-of intersections
6 ]9 F: A6 j- U. F0 m+ p! p" o label-current8 ^2 I2 a* ^2 [4 G+ i2 ?) s6 b
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set-default-shape turtles "car" D* x3 _* P) n+ e, r( z: w, w
& g/ J3 d- ]" Z! m& N7 ? if (num-cars > count roads)
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% V; ?8 k e" y* L6 z f4 f0 f* f user-message (word "There are too many cars for the amount of "$ [" R$ | Y: h7 i) ]
"road. Either increase the amount of roads "6 w# j# |3 n+ r+ a; n$ Q
"by increasing the GRID-SIZE-X or "
, Q$ e: X4 N& `9 U# H "GRID-SIZE-Y sliders, or decrease the "
. \5 h, y' g6 g5 C "number of cars by lowering the NUMBER slider.\n"' @' I* a/ G* I% m% D0 \9 x8 l4 \
"The setup has stopped.")$ i9 p7 K- i. P# R: Z* [0 ]+ X' Q6 @1 z
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color5 B# z2 D( v- f4 @" J
crt num-cars9 e0 P o- x8 A0 g7 {) q: w- E
[
% w. e2 O: [ e T setup-cars
+ X2 B; w$ ^- b e# n set-car-color
% ]/ _$ `8 s9 i record-data
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4 Q( h8 D6 l/ B% h9 t& | ;; give the turtles an initial speed8 F( W3 P6 L7 \: F' a
ask turtles [ set-car-speed ]! m9 o0 I- d2 p0 k( |/ t
" I1 @2 h7 N0 f reset-ticks
" @+ p% s/ t9 h" L$ u) kend
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( m9 X" \9 `/ m3 ^;; Initialize the global variables to appropriate values9 T e8 T6 q ~
to setup-globals
9 Q3 \/ M/ s+ F set current-light nobody ;; just for now, since there are no lights yet
5 b, J! \; T0 R* f4 J* H. J1 e set phase 0
/ K" u* a: h0 _- W" m( ^ set num-cars-stopped 0* q% {# L9 }+ N5 [* M" _7 W) j
set grid-x-inc world-width / grid-size-x
/ `: i7 a4 u8 |! V set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary4 g% Q' E* y ?( R4 w: t8 Q6 K
set acceleration 0.0999 V$ [9 n# ?+ ]3 h+ ~* {
end' |3 A6 p6 Q# m( {1 l
: P' [/ S( k9 I
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,: D+ \) i5 P7 S# I, `+ L6 S
;; and initialize the traffic lights to one setting* h. V' M2 Z* y; u3 [ |2 s
to setup-patches
3 _4 `) c4 ?9 \& \2 p ;; initialize the patch-owned variables and color the patches to a base-color; p) w! H0 b4 b6 B) V3 E
ask patches
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* H) m" |$ w3 o8 \* \$ x0 z* S set intersection? false; Z2 P) U# ^/ T
set auto? false
' K+ U& g8 n3 u set green-light-up? true
- [ M" Z6 a) ]1 f S set my-row -1; [- P) D" D5 l) r# a" S& J
set my-column -1
4 g, D# `8 f- M( M set my-phase -1$ E2 M* |2 d. H$ `$ O& {8 g1 W
set pcolor brown + 3/ u4 y8 S+ w: ~" Q" G% t
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;; initialize the global variables that hold patch agentsets) R; d6 D( n7 x6 Z. B* O
set roads patches with
9 b% s% B; ^4 n% W; f2 Z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or# W8 X$ ^! J5 q0 }' H
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 f, N1 q7 x3 H& z/ H set intersections roads with& @: A, l) Q/ z. D: V* h
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and! ?1 W9 J0 ~% |8 _
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]% n0 L% x% c4 `; c6 o; [, U
! V0 w) P( ]. } C/ v5 t ask roads [ set pcolor white ]1 ~( L$ Q. J% n* P! H- j- h; p
setup-intersections
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3 A! J: h6 B. R. H3 }$ u, j7 Y其中定义道路的句子,如下所示,是什么意思啊?+ G! N" v; o' u" A5 o
set roads patches with
7 x- @3 e& v2 k7 c" b [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
( q& p7 `+ b7 l2 _ (floor((pycor + max-pycor) mod grid-y-inc) = 0)], }/ H& m) g5 y* \+ 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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