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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。
5 O4 ] n/ M( b5 U3 Ynetlogo自带的social science--traffic grid这一例子当中,
; V0 ?: ]0 T3 B: ~globals9 G% [3 K" N; h$ ?
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8 @6 _ m5 x1 P* m" B/ m grid-x-inc ;; the amount of patches in between two roads in the x direction1 g7 U5 e5 Z4 N4 G
grid-y-inc ;; the amount of patches in between two roads in the y direction
% d ^2 a' _# g( O acceleration ;; the constant that controls how much a car speeds up or slows down by if& l1 C3 H+ R* ~& _6 [! `6 w
;; it is to accelerate or decelerate
) D8 _5 }8 o% c8 l M: F, b phase ;; keeps track of the phase
) u; }+ H" ?; e) j" ~0 k num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure2 M. |' ^- S8 D! Y3 M
current-light ;; the currently selected light
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;; patch agentsets* G3 P) e# H# t: u9 R' a& m
intersections ;; agentset containing the patches that are intersections0 W! W1 W7 u, A& f1 }3 ]
roads ;; agentset containing the patches that are roads
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/ X1 y/ j( D! e0 a- ~3 Z) `4 iturtles-own. }2 K1 a8 E* U
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9 v; E! @! E' X4 X speed ;; the speed of the turtle
/ B8 A6 z$ B# M8 Z% Z$ L c% u; i up-car? ;; true if the turtle moves downwards and false if it moves to the right
# l6 b8 g# [8 E3 N2 A wait-time ;; the amount of time since the last time a turtle has moved
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# h& f- T; ^$ B0 Z$ ~9 tpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
" e! B9 x2 o8 s N1 E0 n green-light-up? ;; true if the green light is above the intersection. otherwise, false.
4 l9 i1 z7 t' O$ G, x ;; false for a non-intersection patches.
- f1 \! g( S: A+ A" ? my-row ;; the row of the intersection counting from the upper left corner of the
5 D1 U4 u6 c$ y" ]. g% d: T" W ;; world. -1 for non-intersection patches.- _+ h# P" K! l8 ]* ~9 `
my-column ;; the column of the intersection counting from the upper left corner of the
7 V6 e$ ]1 A3 e9 E& E# u8 f1 T ;; world. -1 for non-intersection patches.2 R. {; ]4 c2 T6 O+ L; x
my-phase ;; the phase for the intersection. -1 for non-intersection patches.3 D5 [" n; {6 |' }
auto? ;; whether or not this intersection will switch automatically.6 a* q8 P7 p( `! A
;; false for non-intersection patches.6 U" T- `2 M4 t4 `: @) V$ t5 ?: _
]
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. _6 ], O- |. {! E m2 u;;;;;;;;;;;;;;;;;;;;;;4 P8 p6 \' `4 ^
;; Setup Procedures ;;
: p# k4 z0 H9 B/ h' X! l;;;;;;;;;;;;;;;;;;;;;;9 ~0 { j- O6 O% L" m: W# i4 e
* Z+ t+ F- }9 B1 N8 B5 K;; Initialize the display by giving the global and patch variables initial values.
5 p# _! T, T7 J% b3 E& h6 ]* f;; Create num-cars of turtles if there are enough road patches for one turtle to
. q( s. f& c0 U: u7 y) B;; be created per road patch. Set up the plots.! R( y% @6 H* g* N, s% y- P
to setup' P5 T/ ?: ?' W A/ U7 F% z
ca
( T0 |6 B# ~6 G" ` setup-globals& }, f6 i! E, G) r/ P6 c
' y' m) @1 y) K1 e9 C5 g5 S2 Y ;; First we ask the patches to draw themselves and set up a few variables
- i8 a: C: P4 V2 F. ^7 D2 S setup-patches
. y* B9 R- Y& m9 G" \- \4 g make-current one-of intersections) {: p k7 `* c
label-current
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set-default-shape turtles "car"" `) q5 f+ r2 P y
( N1 A! `6 ?2 N3 n' ~4 I+ v if (num-cars > count roads)
0 Z4 z& u% _6 _ G" T4 d) v [- ~0 ], ^- b, g6 I i0 P ^
user-message (word "There are too many cars for the amount of "6 q" d) k$ g" E3 p! W
"road. Either increase the amount of roads "1 ]0 ~. ~* j$ A1 u+ Z
"by increasing the GRID-SIZE-X or "$ f* U% f; Q( r! Y4 `% V( I5 {
"GRID-SIZE-Y sliders, or decrease the "9 j/ H6 t- z1 @9 Y. u. x2 b
"number of cars by lowering the NUMBER slider.\n"' H0 Q9 w: H/ f5 q
"The setup has stopped.")3 C4 s% i. m" r- a4 t
stop
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8 h( V: W/ k' i5 T4 y$ ~ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color' n. d9 M$ n$ Y& m
crt num-cars
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! q) S0 X+ J6 {& B4 ? setup-cars
6 h1 P, ?9 C: D9 ]" Z7 b0 Z7 { set-car-color$ H# Z2 B/ w0 y6 R& b
record-data
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- H8 {! I! [$ ? ;; give the turtles an initial speed
" E3 B; U7 |; ^5 L1 \ ask turtles [ set-car-speed ]* A/ I0 a; X, ~; x" v5 d
; t* R, R V y reset-ticks9 q! M; S' ~! d6 ?* h
end) B1 |: V1 b% S- O
; C B) w" y( U$ Q- a7 V% S;; Initialize the global variables to appropriate values0 t! w `- K( ~7 ]# K
to setup-globals
2 S( G8 Z% q0 V. ~& K3 g set current-light nobody ;; just for now, since there are no lights yet
5 K; k) h# b! D n" v+ x set phase 02 b6 o* M0 f, b* @' H5 M
set num-cars-stopped 08 T5 ^3 D+ [ }6 e- \/ d- H, a
set grid-x-inc world-width / grid-size-x& i. T% N8 f$ y/ h* [- |
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 boundary
; G* P8 S/ n2 ?. P( x2 d' F( X set acceleration 0.0992 {! A& ?+ K! j* ]
end
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( ^6 b- U" O1 s7 s3 }/ q;; Make the patches have appropriate colors, set up the roads and intersections agentsets," O& K# Q5 b6 o% Z) I
;; and initialize the traffic lights to one setting6 {5 i3 |( ~* v! H4 }* o
to setup-patches' c9 h) |% T: p2 w }4 c. n/ Q
;; initialize the patch-owned variables and color the patches to a base-color
6 q# {8 K" Z9 X- c! l8 F0 } ask patches
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; P0 l7 F, c4 S+ K set intersection? false
" i5 v9 ^3 N( k o6 ]9 j* [0 Z4 } set auto? false1 o7 d$ b9 @) r* Z( h6 |0 Z, {% ^ W
set green-light-up? true
& |- H" N9 i" L/ Z. E set my-row -15 v1 J( Y% @. R: D, e
set my-column -1
- y. P0 b6 Q! M6 A- q& n set my-phase -1+ [9 |8 a. s1 h
set pcolor brown + 3
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& u7 k0 C9 `+ V, T* C- n ;; initialize the global variables that hold patch agentsets
8 v2 l! @* r: k2 i, i% U d" p set roads patches with
$ G- R- d! n4 B d$ } [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" Z% `( u, j4 j" L# P (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 m# r, `" O3 L) n) K" t set intersections roads with6 n9 y) v& T1 w- ^( w
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and# z8 R; y# T' q: b
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]. C' O9 d- r% E& o( y) ?
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ask roads [ set pcolor white ]! G; | U# k: q& p
setup-intersections j) q7 @) i e- K, j; H3 E
end
4 V4 N! y' \3 [! |其中定义道路的句子,如下所示,是什么意思啊?. l8 ? D5 `6 A7 w/ B' e
set roads patches with& D# I' ~8 D7 n1 c* ]
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
& n6 r! h* E& s- z, u# i' r% V+ i (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. r6 ?! s2 T" B+ `9 {1 Y# P$ A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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