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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。
/ o/ t' G2 O6 Nnetlogo自带的social science--traffic grid这一例子当中,- K; G0 D' I* z
globals" Z. ?6 h7 N& `* O; s# Y- h/ r/ n
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grid-x-inc ;; the amount of patches in between two roads in the x direction# ]* B: b' ?; z3 L
grid-y-inc ;; the amount of patches in between two roads in the y direction% X& J2 l& v5 N' I8 L. Z5 D8 S
acceleration ;; the constant that controls how much a car speeds up or slows down by if4 K5 m/ M& G! E6 _+ p- r
;; it is to accelerate or decelerate' u: S. ?2 b. ^/ N
phase ;; keeps track of the phase
6 j/ i6 m3 W% S- U$ u num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure* r' S/ h# w+ @$ U5 A
current-light ;; the currently selected light
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: r q( H# `" C% n. d3 z- b' e; l ;; patch agentsets- |/ W% {/ q9 P8 ^8 k6 p& x
intersections ;; agentset containing the patches that are intersections
* P' u6 P/ l0 p' R: I) y' b6 s. y roads ;; agentset containing the patches that are roads
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3 x9 L7 a* T _turtles-own
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speed ;; the speed of the turtle5 b* k- p% P# s; b
up-car? ;; true if the turtle moves downwards and false if it moves to the right9 x: \9 f0 |9 Y# [/ k0 b
wait-time ;; the amount of time since the last time a turtle has moved
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' a9 o" ] j" ^- b+ _patches-own
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intersection? ;; true if the patch is at the intersection of two roads
9 L4 X* O1 M5 Z0 p% c. b green-light-up? ;; true if the green light is above the intersection. otherwise, false.
, g C* o5 t, P( w ;; false for a non-intersection patches.+ F3 [2 [4 P9 ?
my-row ;; the row of the intersection counting from the upper left corner of the
0 B4 n6 S) h, D+ E) r. e: N ;; world. -1 for non-intersection patches.' j- I/ v# a/ z$ j5 J- T4 A8 T: t
my-column ;; the column of the intersection counting from the upper left corner of the
$ V7 G+ _0 k& \, q- M- K ;; world. -1 for non-intersection patches.
; ^1 g! H: V; f3 ^9 K/ O: j! u$ P& F1 s my-phase ;; the phase for the intersection. -1 for non-intersection patches." S0 _9 n# y& s8 J: P5 k9 c" m
auto? ;; whether or not this intersection will switch automatically.
3 {1 v0 C4 x: d6 y9 j ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
2 }! N3 U; [- Q U, _7 ~;; Setup Procedures ;;7 A. ^$ |! z9 |7 i7 x
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
* K4 g$ C9 P" Y6 {! X;; Create num-cars of turtles if there are enough road patches for one turtle to
8 a" U* T& V" o6 _- m;; be created per road patch. Set up the plots.
P# S1 ^- V* t0 |3 W' w7 \# }( lto setup
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) l8 Y& ? g7 u setup-globals" Y; X+ U, v- q& }- b4 M! s6 R
3 D$ g+ S$ J% O. ^( K! b ;; First we ask the patches to draw themselves and set up a few variables# o2 `! u$ N* F$ L% C# x
setup-patches
; x2 Y* Q* j* G; u! Y0 Y make-current one-of intersections
2 O& L7 q- `8 H1 ~ label-current) T l) a1 d0 F; N9 } @, m) }
# M0 b7 L& ~! I2 Y' |/ A8 h set-default-shape turtles "car"+ w" p( k" n7 D6 _+ U- U
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if (num-cars > count roads)- L: o* ?' T4 o/ c- |
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7 B: H7 A! k9 s9 y user-message (word "There are too many cars for the amount of "
) R7 A" i8 O) Q8 Q: N "road. Either increase the amount of roads "' U& W* b1 `4 l! }0 P; }- o7 ^/ u
"by increasing the GRID-SIZE-X or "
2 ]" x" l) C, v9 B1 a% v2 I" b "GRID-SIZE-Y sliders, or decrease the "
; x, J, W }! A3 R) I7 P! d "number of cars by lowering the NUMBER slider.\n"- w6 G, m+ @% n6 n- l, f
"The setup has stopped.")
' l) y, ~- E1 b stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
# \) W( q3 W2 a% m! l5 a crt num-cars- u$ K0 D' b) ]' h$ B& P# m9 Q
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setup-cars+ w5 g |: B/ e8 L3 a
set-car-color0 p' m* A0 o! a* h0 ?
record-data- k- O- A' Z& Z! H! g( l( c
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: I7 E4 o9 F7 Y ;; give the turtles an initial speed
R7 ]( z+ L" n% G4 [2 K ask turtles [ set-car-speed ]3 l3 k: P. l8 C D" E
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reset-ticks* D1 B5 N: {. @) W
end( G- u1 l. \+ }4 Y9 j4 j! Z1 p
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;; Initialize the global variables to appropriate values2 k: ]$ h, ]6 w8 A3 R, b
to setup-globals* Z, q' ]& \: s# W3 T% [* h
set current-light nobody ;; just for now, since there are no lights yet
# d$ Z" K4 N( c/ a+ M* N set phase 0
8 N1 z- T1 k" a( f/ d set num-cars-stopped 0
/ D. F: Y1 l# ^$ q H/ l3 B set grid-x-inc world-width / grid-size-x9 g' |" c' f, x, a) }' {
set grid-y-inc world-height / grid-size-y& d* [+ |) J2 d8 J) X* l* o
( l7 d* K ]$ C; [) `5 ^. h6 o) o" x9 k ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
9 B' |3 D% L. C7 y6 K set acceleration 0.099( X2 c) H( q: r% R3 \
end! ` i3 a0 L+ z' H
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,- J v7 k( ?. q |: `
;; and initialize the traffic lights to one setting
- v# M/ \9 k: B. J8 Q5 Z0 ]to setup-patches
5 c9 Y8 e2 f! Q6 T7 T3 A& Q, } ;; initialize the patch-owned variables and color the patches to a base-color
% G8 o% a5 r/ t; d, L ask patches
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# }' X8 ?# ?$ l set intersection? false- C. U ~" q Z2 K5 H2 c8 m
set auto? false
9 v) S( Y6 z. i* W( @2 E set green-light-up? true$ W0 P" j% p2 ?. e
set my-row -1; E& b* D1 q }2 z
set my-column -14 c3 k% e$ {: \ B# v1 }
set my-phase -10 A$ n. X, c" z& f" n
set pcolor brown + 3
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% k' G6 N3 g* K2 p8 Y1 }, X$ Q x ;; initialize the global variables that hold patch agentsets
+ S+ e! `7 G, _ M3 ] set roads patches with! X/ b! {5 R- B/ T
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) E! ~ ]+ }$ I' O# s( V' ]4 n! ^
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]: h& i" |+ m8 o8 ?# d( Y- x
set intersections roads with' y5 M2 ~. W) Z; M$ b' m
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
9 B) l e! T' n) c (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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, M; X9 c1 @4 R ask roads [ set pcolor white ]- T: s) ^ q$ u: W m
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?4 Y+ _, B b# ~
set roads patches with
; l. |( `6 X: c2 q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or$ k: z. K4 P$ W' ]
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 Y9 y7 K( [9 w3 I, I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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