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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。- k& V4 Z& }* I8 W
netlogo自带的social science--traffic grid这一例子当中,
# D6 F: T5 T3 s; I& Oglobals
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1 B- z* t& g2 D$ {3 r grid-x-inc ;; the amount of patches in between two roads in the x direction, g, C/ W0 Q3 o' m* w
grid-y-inc ;; the amount of patches in between two roads in the y direction. L U. a0 \$ }& w* o
acceleration ;; the constant that controls how much a car speeds up or slows down by if
$ H& U% `0 P& n7 n/ D: G% \" n ;; it is to accelerate or decelerate4 S c. e( C, H6 w; A6 T
phase ;; keeps track of the phase. @$ ~/ J. }3 x9 V
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure3 a) z- ]- [7 w' G, v9 [
current-light ;; the currently selected light
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;; patch agentsets
% }# ]# x. S9 L8 a/ U intersections ;; agentset containing the patches that are intersections0 H: _$ A% S, y; `* s
roads ;; agentset containing the patches that are roads& u* k: p* O- Z; w
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turtles-own, V) Y' O1 s! o8 }
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q+ |: E& E+ g' Y speed ;; the speed of the turtle$ e3 ?5 X* n" `6 {& L( Y$ z3 ~* r
up-car? ;; true if the turtle moves downwards and false if it moves to the right
5 O7 G! s3 p4 s wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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/ E, Z' p) @. A6 \& ^+ N$ w intersection? ;; true if the patch is at the intersection of two roads) C/ W9 }# f6 \/ Y
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
% c2 [2 V6 p; n' \ ;; false for a non-intersection patches.
% o% ~% Q! w" k" j% _; a( x my-row ;; the row of the intersection counting from the upper left corner of the( r A" ]& N8 c/ A
;; world. -1 for non-intersection patches.
8 v- H& A H% H( U+ l my-column ;; the column of the intersection counting from the upper left corner of the
; b& F& _$ `# t ;; world. -1 for non-intersection patches./ R' h, X8 s A$ _- I
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
$ z8 H2 R0 C3 q- M; j& G! q auto? ;; whether or not this intersection will switch automatically., @ i: ^* {/ [' v
;; false for non-intersection patches.
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! \7 N& u2 P; w" r;;;;;;;;;;;;;;;;;;;;;;. o# Z5 E+ f. r0 k, R% \1 I. E
;; Setup Procedures ;;
2 B0 M8 Y1 y4 h, Q: M;;;;;;;;;;;;;;;;;;;;;;
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0 [+ }* ]; Y( A;; Initialize the display by giving the global and patch variables initial values.
0 U; ^# M* V" x/ Q5 \1 ~% M8 L;; Create num-cars of turtles if there are enough road patches for one turtle to
J5 L- h) ~# l, q$ y; H1 H, M;; be created per road patch. Set up the plots.5 M2 `% A: h$ |
to setup
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6 E/ q. P) E% F setup-globals) Z( w0 N3 z3 p: w( z2 T
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;; First we ask the patches to draw themselves and set up a few variables
( f3 |3 s }, b2 _4 P; R setup-patches
9 t8 E1 H. X4 U+ n% H4 F7 H# K make-current one-of intersections( R, v- h4 u' t0 _% C
label-current
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set-default-shape turtles "car"
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4 @% x* ^4 @3 h if (num-cars > count roads). W9 F% g. t5 K& _6 j9 e$ o# x
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- \# J/ \) q1 \- l user-message (word "There are too many cars for the amount of "! Z5 Z- [2 f) \) c* [6 p4 Z$ I
"road. Either increase the amount of roads "4 w$ W& o: {5 d! L: b# H F
"by increasing the GRID-SIZE-X or "7 J8 T. z* X( y+ L
"GRID-SIZE-Y sliders, or decrease the "
Z/ G$ [$ b7 m. z. U! u+ T "number of cars by lowering the NUMBER slider.\n"
& V) @- _1 F' D) ^" v9 d "The setup has stopped.")
- z2 w4 ~8 L3 r+ D stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color5 l6 G1 @! v& I' `" c
crt num-cars- { V4 ~3 p, j% q
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1 }5 i) `1 Z, T& l- k setup-cars
0 y& Z. C6 H* a0 p set-car-color; m3 P7 ^, n5 h( J
record-data
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;; give the turtles an initial speed5 {& g- Y c1 q& x
ask turtles [ set-car-speed ]4 n6 H7 d- f1 U$ \& ~0 A: K, `
/ l `; q+ [- {* m5 m2 i- N reset-ticks/ P/ f% K& w6 ~+ |
end
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, e9 n# q2 {/ Q" k! ?9 \;; Initialize the global variables to appropriate values
7 x! m6 c' c# `, Z+ L- S" e9 hto setup-globals
, y2 U$ S) h8 b set current-light nobody ;; just for now, since there are no lights yet
9 D" p- K& ^0 ^7 L set phase 0
4 b; U" |$ A h8 w0 e set num-cars-stopped 0
' l( w+ _9 ~$ y* H7 n: L set grid-x-inc world-width / grid-size-x
7 K$ H: Z2 K7 y set grid-y-inc world-height / grid-size-y: h$ O5 y. P4 d7 u1 U i: \ C
3 @0 J6 t+ _, }. Y, g7 H ]' T ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary) I4 q( h8 y' B1 {4 v5 f: L+ x8 K
set acceleration 0.099
3 P c. A- E8 {) \) d7 M7 _4 xend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
0 P/ G- E4 U) s3 u s( s4 N;; and initialize the traffic lights to one setting& Z: \; }* x" ~* D+ O. l$ R
to setup-patches& F- B+ ]( F8 f* Y( o1 M
;; initialize the patch-owned variables and color the patches to a base-color
0 Y$ I! i# Z ?" [# E ask patches' F1 @& W* q! \- z& X* E/ d; X
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+ S, U2 \8 z! ~8 w; J. n set intersection? false# ~, h7 y6 \, {5 H; Y% w0 |
set auto? false1 s9 G" f) C% f
set green-light-up? true
: Q# Y1 m% o3 D2 s# g) U% A& G6 Y set my-row -1
q B3 W0 O( F set my-column -15 H/ K, [% ~4 e' a* }
set my-phase -1$ m+ h: q# U- v+ w
set pcolor brown + 37 J6 r0 f9 r. i) R8 S, i
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' a5 l( f% {5 a+ F# ^1 D: f ;; initialize the global variables that hold patch agentsets z- r! U" f" z v9 e' c
set roads patches with# e% T3 J6 E f* o- y1 K7 x
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
) q* a9 i% H1 d. L" ] (floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 V- c$ `# A6 d7 y! f
set intersections roads with
0 v: L2 j' U; z& v& x6 { [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and2 r$ Q* Z8 l9 I# t4 ]6 ~" J( ~
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 v- p, J* `7 H: H$ p
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ask roads [ set pcolor white ]8 E; o# A. d q! z" p6 h
setup-intersections% e+ Q1 E; } V, ?/ I/ p: t. Q
end: S5 n. P- |) s- \- Z
其中定义道路的句子,如下所示,是什么意思啊?( g- _: P) f" e$ V
set roads patches with, Y. b: e& b/ l; f t$ m
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or( [8 ~ p9 y* i U7 Q$ V/ Z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ a4 }" X8 Q- Z8 ]% G, ~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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