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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 Z, R9 L( L2 U
netlogo自带的social science--traffic grid这一例子当中,# L& ?3 [( G1 Y5 c
globals6 B+ L* V, G% C% j. l
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& w; p a6 R3 @& T, q5 [. n4 z, e grid-x-inc ;; the amount of patches in between two roads in the x direction
5 s2 r- L! ?" f. d! o" {6 Q* B grid-y-inc ;; the amount of patches in between two roads in the y direction2 e# X$ A {; ?2 ^8 H! D
acceleration ;; the constant that controls how much a car speeds up or slows down by if* ^/ T: _+ v8 H+ B" Y/ \7 x8 u/ _
;; it is to accelerate or decelerate% Y9 j/ {- M9 R$ K u
phase ;; keeps track of the phase8 R$ T- Z4 P' i; X
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure! g$ _* E9 v( D8 x8 B
current-light ;; the currently selected light
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8 S9 y _3 j( q+ o* n4 ] ;; patch agentsets
f+ x9 `, W! m5 b8 `( p intersections ;; agentset containing the patches that are intersections
* u- V6 I- u2 T" ]5 ] roads ;; agentset containing the patches that are roads8 P- J) y$ |3 h
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turtles-own
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* O/ R2 u! a; S speed ;; the speed of the turtle/ I+ v6 e. M3 v/ @
up-car? ;; true if the turtle moves downwards and false if it moves to the right# a; x. _ t$ q% t
wait-time ;; the amount of time since the last time a turtle has moved
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! O/ J8 F- E9 C1 m3 g- vpatches-own
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intersection? ;; true if the patch is at the intersection of two roads+ z' M: H8 ~) m0 ]8 [! z o
green-light-up? ;; true if the green light is above the intersection. otherwise, false. `$ U1 w8 u$ H- g$ e' S! j
;; false for a non-intersection patches.* g! u. o Z1 T1 m
my-row ;; the row of the intersection counting from the upper left corner of the7 M& }! ~- N/ E$ D- D
;; world. -1 for non-intersection patches.5 h# ^8 k" `- G0 w9 a1 M
my-column ;; the column of the intersection counting from the upper left corner of the
" Z. l0 s: ]3 H& Z( A7 q ;; world. -1 for non-intersection patches.
9 h$ j( L! L- n# A my-phase ;; the phase for the intersection. -1 for non-intersection patches.& S% }- `! ^- i `, b
auto? ;; whether or not this intersection will switch automatically.
4 }2 Y- g" d T$ M4 i) p( x ;; false for non-intersection patches.! b9 s0 C( f/ H& B
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;;;;;;;;;;;;;;;;;;;;;;
2 R; P+ r o, q6 A, W, n/ I;; Setup Procedures ;;
% @: p5 p& y, m' h7 e/ k4 |9 x/ j- E;;;;;;;;;;;;;;;;;;;;;;, I) J" z! H; h; z/ V+ g4 G. Y
2 G, G$ n, m! I4 u' R;; Initialize the display by giving the global and patch variables initial values.1 [4 [4 z9 r% i4 _$ h$ x2 u7 m
;; Create num-cars of turtles if there are enough road patches for one turtle to+ F( Q( n/ C: ]6 d
;; be created per road patch. Set up the plots.9 r$ B* |* H8 d& l
to setup, n! h% }) @" X9 J9 q" o3 B
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setup-globals
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2 W" s/ q. `* c+ u1 l( R% t% v ;; First we ask the patches to draw themselves and set up a few variables
. t7 v1 u' j2 b9 I: B setup-patches' j8 U) X& _2 t: ~. x; v
make-current one-of intersections# y, b3 C$ b$ Z( c. m$ Z
label-current% m# h0 }* C4 S
8 y M5 k& Z. Q" E. n3 X: V set-default-shape turtles "car"0 N$ J9 c7 S3 Y
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if (num-cars > count roads) f1 \; M0 m Q2 w
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user-message (word "There are too many cars for the amount of "7 T. V3 X! s% E( |& u+ n
"road. Either increase the amount of roads "
$ T, z$ D; I. j& B- ~$ Y( ] R4 b "by increasing the GRID-SIZE-X or "$ c: z |" M% Z
"GRID-SIZE-Y sliders, or decrease the "
1 `; N7 ~/ P7 a: W$ b8 r "number of cars by lowering the NUMBER slider.\n") e9 O1 Z c* T0 N3 E% c3 D
"The setup has stopped.")
6 g3 O, W7 Y7 F* H* U' B, p& z stop
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7 x5 ?9 \9 K& \( G0 V+ g) S ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color+ Q" o8 o: d& l: P) U8 G. M( R0 y
crt num-cars3 ?/ q0 k& M- Z+ m5 P6 w
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9 T$ b- w9 p u: J, g2 K9 ~& b setup-cars
# v+ M }. e8 {8 q! K set-car-color
" _* Q9 ~% c: q8 C2 i+ ]: |9 S0 M record-data
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;; give the turtles an initial speed
1 F, S [- v/ c" } ask turtles [ set-car-speed ]8 `( p5 }& f& t% i0 y) D2 d
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reset-ticks
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+ M/ F) s8 ~) Z3 W$ Q;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet) Z g) \/ N- A4 [% [
set phase 0& ]+ g3 O9 @+ E: y
set num-cars-stopped 07 s+ X- D. x" m# F
set grid-x-inc world-width / grid-size-x3 E; ]# }' a3 U. I
set grid-y-inc world-height / grid-size-y6 a2 t' Y4 a* r1 X
- O2 V( k2 I2 D ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
! R- O" u! r4 v( v6 z set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,9 s6 @: G' ~* j6 H
;; and initialize the traffic lights to one setting4 O0 k2 _; ]2 s; _8 z C0 z/ x
to setup-patches
4 v: }1 e3 z" X: p! q# X& P6 a* G- Q ;; initialize the patch-owned variables and color the patches to a base-color
I8 V) t" O, V% m ask patches
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set intersection? false( A) |2 {* ~' T2 X: Y
set auto? false
! E0 S* G7 H+ t t/ h' n4 f: F set green-light-up? true7 ^+ |3 W! e- p1 t' |: x" @0 }
set my-row -1
( r2 A8 q) L0 H7 f( I" f set my-column -1 O* B! u# z) G- i0 z3 p3 [2 T
set my-phase -1
/ Y& S4 R$ c8 C& t( X set pcolor brown + 34 w! p& |8 D& o; Y' Z* @% D, g- F
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" [4 X0 _3 L5 x) P ;; initialize the global variables that hold patch agentsets
3 n( R, |7 ?/ C( X' s+ C9 F set roads patches with
' {# |! Q; c- z% Y; ] [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or# j$ H0 k! W4 N& s7 m1 D, ]( A
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# g9 F( M8 Z2 ^: w7 l# |/ n% k set intersections roads with
$ J" S) j2 e; n% R* } [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and' l: \' j, y$ S( X
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]1 D1 O) U6 T. \2 S1 O0 f
setup-intersections; @$ T3 S, a) _% u* u
end4 E/ x0 `9 B* L1 k
其中定义道路的句子,如下所示,是什么意思啊? K% |2 c h' k- g+ O
set roads patches with
/ a: @! ^) }! u5 g [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or1 Z& W2 e- G# b' B% l
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 m6 S* w- J" u' N Y
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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