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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。9 h6 y# G% u3 i; q% s, I
netlogo自带的social science--traffic grid这一例子当中,% {, V# E- p5 k+ D
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction6 f @6 o% I% @
grid-y-inc ;; the amount of patches in between two roads in the y direction
6 M9 k7 J8 Z/ o1 P" d9 g acceleration ;; the constant that controls how much a car speeds up or slows down by if
9 N6 N3 B2 A2 e ;; it is to accelerate or decelerate
; h+ Q" E% c6 a+ ~ L7 N* \ phase ;; keeps track of the phase6 `8 a6 A& f$ P% \. l
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure8 h9 F6 g w" w) r+ H& B" u7 Q
current-light ;; the currently selected light
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;; patch agentsets' i2 I, j4 ^" d6 F* k
intersections ;; agentset containing the patches that are intersections* O0 \: k: B+ {: @: D) [/ m& p
roads ;; agentset containing the patches that are roads" u8 B* X S7 S: p
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turtles-own' l+ v& l9 C- \3 q! T+ B' ]/ _0 Z& J
[
: t/ [1 d7 \% B3 p speed ;; the speed of the turtle
( b7 ?6 _; E& P4 \6 e' B up-car? ;; true if the turtle moves downwards and false if it moves to the right
- ~/ J& I! I# P wait-time ;; the amount of time since the last time a turtle has moved9 _# X3 d' L# J0 [
]
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( c& I) l7 L. ?patches-own
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2 c& v- r# o: }( O intersection? ;; true if the patch is at the intersection of two roads* B* B7 h" S' n2 N) p7 B
green-light-up? ;; true if the green light is above the intersection. otherwise, false., u* U/ O( R, O& H" l; P
;; false for a non-intersection patches.
h& W D, b: W4 w) T my-row ;; the row of the intersection counting from the upper left corner of the" y( `( @2 T) c3 e9 e
;; world. -1 for non-intersection patches.
% y! I% ~/ f* C4 k2 ^) Y. i: o my-column ;; the column of the intersection counting from the upper left corner of the, s3 A u* C2 s* v% d
;; world. -1 for non-intersection patches.0 j, u V+ R B0 Y
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
$ U) ?3 c% v7 v3 S4 l$ E auto? ;; whether or not this intersection will switch automatically.
4 } F5 Q. @: D; c5 _6 I ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;" _# G- K. T: ]- s& _; ]# z
;; Setup Procedures ;;) G$ E* Y. o( }- ]& _
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& L& ]! W/ o; _8 S/ O3 q8 F;; Initialize the display by giving the global and patch variables initial values.
' a# E+ K+ u4 J5 f9 `2 M: C4 k- a;; Create num-cars of turtles if there are enough road patches for one turtle to6 T, t1 d9 D& L* t" q, X
;; be created per road patch. Set up the plots.2 b" Q* l2 Y3 F: t T
to setup" J. J" n( |+ G$ T0 R% }' Z# |, \, P
ca
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. w! a# t/ P, D* k/ B* I ;; First we ask the patches to draw themselves and set up a few variables( j" J5 P: {3 }5 m W/ I7 w& g5 r
setup-patches7 Q2 @- ?& N3 N: G& T$ [
make-current one-of intersections
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+ A* Y }9 ?2 i: O" L' O set-default-shape turtles "car"
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/ c0 R* B. ?2 D if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
" B8 a9 y$ B1 e9 s/ O. C4 } "road. Either increase the amount of roads "
; k" O+ k' n1 k" C7 G& r "by increasing the GRID-SIZE-X or "7 w ^' w1 p2 i; M
"GRID-SIZE-Y sliders, or decrease the "
. T; z* U0 ^# }! y m/ ` ?) j "number of cars by lowering the NUMBER slider.\n"
1 O+ {/ z$ }+ P( X' |/ i! [& [; |. a "The setup has stopped.")
7 I, P6 ~" `3 W6 B! _' T; Z1 c stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
% ]9 Z) b: K. ?; m% Z9 o# q& ~2 v crt num-cars
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setup-cars/ T- \! @! T! a0 w/ b. H
set-car-color" d' t& e8 \1 A# v$ w
record-data
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;; give the turtles an initial speed& u! g6 }9 Q9 G% B2 b1 b/ f
ask turtles [ set-car-speed ]/ s n6 ^8 r8 [, d$ I1 F. p
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reset-ticks
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/ t; Y/ k& |1 t5 f% c7 A;; Initialize the global variables to appropriate values
8 I* h/ }! l! T& ~4 t9 bto setup-globals
8 \- s- A! J7 [, P' ?+ n9 } set current-light nobody ;; just for now, since there are no lights yet5 C. Q3 y) X. T
set phase 0
! m7 W! s { |$ r5 D- T5 q set num-cars-stopped 0. `0 \, n4 i( @6 @# v% e5 J3 c: C
set grid-x-inc world-width / grid-size-x
) {- Y# ~2 q! V+ I* {1 w set grid-y-inc world-height / grid-size-y3 x0 S- y" `7 T4 C( 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& T0 x" o- j0 r) v" g. D3 U: V
set acceleration 0.099+ q: v" k+ m% D2 B
end2 s" q& [1 E$ A5 y7 `: |/ R
& l9 n7 ?% _$ V K" x R$ c: S;; Make the patches have appropriate colors, set up the roads and intersections agentsets,* {/ ]' T' o) _) E3 d6 L
;; and initialize the traffic lights to one setting
4 a3 _, L' _4 Pto setup-patches1 R& z' y+ I9 }
;; initialize the patch-owned variables and color the patches to a base-color
' ^+ R! L0 f6 S' a3 b$ }0 L& L ask patches3 H6 x7 {3 x: g7 X
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set intersection? false
S8 i6 W, V4 v! q+ N7 s set auto? false, J: V- G8 _, L5 F" f
set green-light-up? true0 o" Z1 R( i5 P: J* U9 y
set my-row -1
; W# a! X- c4 ^8 T1 g T set my-column -1
! n: F* V5 V2 _$ z$ g% u+ b8 E set my-phase -1/ z( z7 W! Z; ~1 q& n# E
set pcolor brown + 3
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( v$ y2 g. R9 }% q! _' P$ `5 U ;; initialize the global variables that hold patch agentsets+ }9 o1 t; |) C: c% `! B$ `! ~" O9 i
set roads patches with" [6 h$ |3 n# y6 [
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or( n% h7 g' n7 U- T( e/ O0 @
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]! i: F1 ?/ w6 J* z, A2 ?/ B
set intersections roads with" F3 N+ [7 n# J% J' n$ r% m
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
( P% n, f/ h* [( J (floor((pycor + max-pycor) mod grid-y-inc) = 0)]! h3 y; Z% r3 ?5 D
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ask roads [ set pcolor white ]
/ _# _; ]; V& B setup-intersections
3 L$ b8 e7 N0 O3 h1 z$ l- k+ Fend
4 v8 z' R' `9 @其中定义道路的句子,如下所示,是什么意思啊?4 C! f. S$ Z6 D+ h# H" j
set roads patches with
2 g2 c0 u1 P5 H [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
- Y$ T a$ Y: l% r/ C (floor((pycor + max-pycor) mod grid-y-inc) = 0)], k& I: f- a$ A; u) D' N# z6 S3 p/ T
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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