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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。 m$ c3 @5 n/ `0 H
netlogo自带的social science--traffic grid这一例子当中,
9 i7 [) o& Q" Dglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction( N A+ ]4 I7 g' u8 \
grid-y-inc ;; the amount of patches in between two roads in the y direction5 L D6 I. o' }! k+ o# D- X+ n2 w! O
acceleration ;; the constant that controls how much a car speeds up or slows down by if
! |' E2 Z# P! A3 w; y f ;; it is to accelerate or decelerate/ R1 n8 g+ i* a6 _4 x
phase ;; keeps track of the phase+ L3 W/ Z- l+ V
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure. J, d" P) o( d2 P( ?+ b G6 r. ]
current-light ;; the currently selected light
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I3 Q5 g9 W: g) ]5 `: k ;; patch agentsets
4 w) i7 ?' l* M* B. ? intersections ;; agentset containing the patches that are intersections7 o- `( B! N4 B& f# ^
roads ;; agentset containing the patches that are roads! N1 r& K- b9 Q. Q
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turtles-own
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- a) A1 ~. d& F9 y N, E speed ;; the speed of the turtle
|8 e+ H, h$ g5 Q4 d8 o" w up-car? ;; true if the turtle moves downwards and false if it moves to the right
8 s, P7 f- `; v. g wait-time ;; the amount of time since the last time a turtle has moved
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1 S3 ^7 X6 t9 u2 l2 a0 Q! P% Lpatches-own1 q3 l7 l# d% Z, d& I
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intersection? ;; true if the patch is at the intersection of two roads' W& r$ x/ x2 o% f7 `) \3 |9 j
green-light-up? ;; true if the green light is above the intersection. otherwise, false.* x5 b& F. c% S8 |. ~
;; false for a non-intersection patches.( Z& H& Y# w% K* P p* ^
my-row ;; the row of the intersection counting from the upper left corner of the
+ x" B0 @+ ]" d ;; world. -1 for non-intersection patches./ o& p3 a8 T) l9 E: w. Z
my-column ;; the column of the intersection counting from the upper left corner of the0 \% M6 X1 ^- S( a- q* ^4 j( u1 W6 {
;; world. -1 for non-intersection patches.# p: h) R; \8 R/ O
my-phase ;; the phase for the intersection. -1 for non-intersection patches. |7 Q5 w6 I c, b# q" s3 ^1 Q
auto? ;; whether or not this intersection will switch automatically./ R0 ? E2 l7 J# o
;; false for non-intersection patches.
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5 z: J. j7 ~) h3 w* h;;;;;;;;;;;;;;;;;;;;;;
$ k& f0 z1 k) V: R; ]' d- J: k;; Setup Procedures ;;* ~8 s# S) P0 ]3 J0 w! S
;;;;;;;;;;;;;;;;;;;;;;, [5 |0 C, T5 H* k. N
- T6 P3 e" [, y' {4 |# G: F H8 Q;; Initialize the display by giving the global and patch variables initial values.1 }$ ]+ F) r8 v( e4 Z/ z
;; Create num-cars of turtles if there are enough road patches for one turtle to
5 J( o! q, T7 Z4 ^;; be created per road patch. Set up the plots. e! {& R( c$ Y. S( S$ b r
to setup
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. _, T& l! U, q' s, ~, [ setup-globals+ t" a2 O$ b5 U0 Z$ r# b5 E& ] U
* ?# o* E* h8 Q1 y ;; First we ask the patches to draw themselves and set up a few variables" r2 j( j+ }8 G+ k7 C
setup-patches
4 N- D7 w' i/ S" W5 x. r5 U make-current one-of intersections
& v+ I- x- f0 ? label-current
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set-default-shape turtles "car": `# U$ Z) q `1 d' i5 w6 y
& A u. ^5 U& o: K if (num-cars > count roads)
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( ^1 [: x" q4 _. D user-message (word "There are too many cars for the amount of "
+ |: a# H" E6 z8 c$ H& f V# J2 z "road. Either increase the amount of roads "
7 k* s" C2 M0 b4 A/ I, } "by increasing the GRID-SIZE-X or "- \6 j2 e+ R" N4 m# i7 b0 o
"GRID-SIZE-Y sliders, or decrease the "
* F0 k* {, G5 T4 L L0 U "number of cars by lowering the NUMBER slider.\n"
: m3 ^6 f( w5 j7 Z0 C "The setup has stopped.")
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
- u( D8 o) v6 G& A* p, l crt num-cars- }$ L# u9 `( W# W! P# D
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setup-cars
2 C3 y9 o( t9 M. s% n set-car-color/ Q; h. B' [% b% o! f( p
record-data
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;; give the turtles an initial speed
/ R7 Z, K5 `: N1 j% ~, [ Z ask turtles [ set-car-speed ]% T, L2 M0 l- p8 b: c! I3 z
9 z3 }' |6 p% K& ~ reset-ticks
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet& k4 x2 W5 C" M" J2 r
set phase 0( y' W0 V( ?' P1 w2 r6 u, n* U
set num-cars-stopped 08 v, N6 r$ v$ F- c
set grid-x-inc world-width / grid-size-x
- j! u; {/ ^+ n, a' |8 X0 Y% P set grid-y-inc world-height / grid-size-y" X1 a* A% G- D
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
5 D4 a! `; p5 X) C set acceleration 0.0994 P0 h Y6 H" e' h
end& i5 v9 R& i5 ~. j; b* h" X% D1 ?/ c
& `& w" ]- j& @9 U+ q; O b; O;; Make the patches have appropriate colors, set up the roads and intersections agentsets,5 j0 B& f; K2 g6 O* _ O5 o
;; and initialize the traffic lights to one setting
0 o$ M( \* L& X( y1 _% e4 ?( Vto setup-patches
' w) e" O0 n+ a# Y( R ;; initialize the patch-owned variables and color the patches to a base-color7 s; E# j# x0 u! N. c1 Y& ?
ask patches
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set intersection? false8 X0 {# C- T- t" a3 s3 E
set auto? false0 `; x6 ?2 C) H
set green-light-up? true
3 ?- T5 Z' H$ R3 R, m" g set my-row -1- r* \/ b* K6 p
set my-column -10 A# v T7 Z0 g/ G: ?
set my-phase -1
2 c) x9 s7 q ~! @4 P' r0 _4 Q set pcolor brown + 3" `$ e/ a2 K. l( y" _
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;; initialize the global variables that hold patch agentsets
% A6 j1 \& _6 y2 b! X% z4 m set roads patches with/ ]7 F$ |/ O# J v! T) F' c
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# v( Q2 u! S' k0 _ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 v: d5 _6 B v5 {1 I, A% J8 Y set intersections roads with
A: r- X; [" g) N( u& b [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and/ C0 m6 q4 O- h
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 M; y* n% H5 i& ]2 ?
( M: z; ~# I; p' P, j0 i ask roads [ set pcolor white ]) j* T( `2 E) h2 s
setup-intersections: U0 ~$ A9 I x: X; Y& i3 \
end
& l5 e4 x l0 E9 ^/ ?9 N其中定义道路的句子,如下所示,是什么意思啊?# h# z" J( m( |8 E, A1 ?
set roads patches with( F: @2 ^- \( A
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or- H$ o8 K1 _1 i, R% X
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. u& P/ M' E) b3 A4 E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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