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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。) g1 y7 }4 c# i# n3 M \
netlogo自带的social science--traffic grid这一例子当中,# ^" s+ k9 f5 k; Z. k
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
! y0 V+ f) x+ y+ k! w, s grid-y-inc ;; the amount of patches in between two roads in the y direction* E% t, B" ~1 k* D- G; }
acceleration ;; the constant that controls how much a car speeds up or slows down by if0 ]% r8 q5 u7 h% I# h6 N
;; it is to accelerate or decelerate1 ^* N5 h0 E% W, ^( Y9 B' d
phase ;; keeps track of the phase S' o n9 v( S) A) b$ L0 Q
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
8 o/ j+ {; u/ z( `: t current-light ;; the currently selected light
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;; patch agentsets5 F& V; v) F! Z! f4 |2 W
intersections ;; agentset containing the patches that are intersections
6 j% N$ l/ q$ @' a+ I/ l roads ;; agentset containing the patches that are roads! o$ u* ~4 q* l% @) m5 \: \6 ?8 F
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turtles-own. _7 }$ Q7 J( `7 |
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speed ;; the speed of the turtle
- E5 }) D* y# Y up-car? ;; true if the turtle moves downwards and false if it moves to the right
+ W' g+ C0 t+ |. S wait-time ;; the amount of time since the last time a turtle has moved$ _! Z( Z+ T+ ?; G
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patches-own: i O* o3 C7 z" Y( h* P
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0 c/ R: C2 E V; E intersection? ;; true if the patch is at the intersection of two roads
8 N+ y; B' X8 ~6 | green-light-up? ;; true if the green light is above the intersection. otherwise, false.# e$ B. E& d. ^" }& v& D
;; false for a non-intersection patches.
1 _1 W1 ?2 j9 d0 s my-row ;; the row of the intersection counting from the upper left corner of the r' `- h& q' W( L% W: ^, W9 p/ E# d- V/ M
;; world. -1 for non-intersection patches.
% `7 ~! c1 o3 v4 q9 X8 T! I/ J* W my-column ;; the column of the intersection counting from the upper left corner of the
0 y4 d3 w, n' }+ T7 b" \& H# C" ]0 S ;; world. -1 for non-intersection patches.
3 K- R% X: k3 }. Q' P8 q my-phase ;; the phase for the intersection. -1 for non-intersection patches.% R7 t; |7 J B. h" V
auto? ;; whether or not this intersection will switch automatically." ~, v' F' A% }! R- K. t
;; false for non-intersection patches.
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- x( C. L/ @% z/ s& J2 ]: u ];;;;;;;;;;;;;;;;;;;;;;
, m% B/ K8 R4 m& J( T. j# ?' m;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
( n% I9 ? g8 t' Y) f0 J;; Create num-cars of turtles if there are enough road patches for one turtle to3 D' \1 ^. b$ H$ Z
;; be created per road patch. Set up the plots.
) s7 \5 ?& @! Y9 U" c% b' Dto setup
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- r9 ` c1 Y4 A$ q setup-globals. B/ x; e' a, z/ h. ^
1 c$ A* p$ _/ e7 t* ` ;; First we ask the patches to draw themselves and set up a few variables6 A: u- b, z& {9 S/ h
setup-patches
: @7 G2 G$ e# \* _ make-current one-of intersections
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6 x7 c$ Z& G9 n4 N# D' R set-default-shape turtles "car"
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if (num-cars > count roads)5 ]' P2 Q' {3 E/ m+ Q7 A
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user-message (word "There are too many cars for the amount of ": S d; V" I6 `) b6 a' |4 W+ S
"road. Either increase the amount of roads "5 m7 c! C; c" \8 W5 {
"by increasing the GRID-SIZE-X or "- W4 Z5 S) G! n/ R
"GRID-SIZE-Y sliders, or decrease the ", S }4 {8 z9 v, P
"number of cars by lowering the NUMBER slider.\n"9 a7 Y, A! ]+ m' O5 m
"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' m; _# R9 d8 A
crt num-cars
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' p$ r" M, G8 c( k1 w setup-cars
0 u5 a% f3 V5 }+ y set-car-color' [+ `; n* b: f, e' e) H
record-data
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8 s k2 r y' @, d ;; give the turtles an initial speed
) _. \* y8 Q e! r" |' O ask turtles [ set-car-speed ]
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reset-ticks6 f2 {8 m7 O/ s9 a, Z& @
end/ ]* E# M( N/ r! z' ~$ q
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;; Initialize the global variables to appropriate values4 N" o! o# q' d$ i @, Y
to setup-globals: Z* O1 X6 z) ? X& G
set current-light nobody ;; just for now, since there are no lights yet
+ r1 X! T# P6 E8 K set phase 0
- ^) D5 D% g3 P. m; m5 `: e set num-cars-stopped 0: V. q) B3 M d3 M3 `$ [
set grid-x-inc world-width / grid-size-x
1 [0 f/ T1 q: Q0 j% ?$ k3 Y$ g set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
) R" ]0 ]- D# G/ h z set acceleration 0.099 Q [) }6 r8 k* g _9 A
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,8 G$ o, c( T; ]! B
;; and initialize the traffic lights to one setting
3 \2 G1 L v. g) C- dto setup-patches, F, r- k4 a: V1 j% j: [
;; initialize the patch-owned variables and color the patches to a base-color5 u6 C: T! s# |5 [ O# V9 P# k
ask patches
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set intersection? false7 A! E9 K$ k; {1 k! W7 ?
set auto? false) {0 Z7 \) G4 x; M5 k* Y1 s8 q$ u
set green-light-up? true( x8 Z, U: C( f
set my-row -1
% w i0 j* k: X$ X set my-column -1
( r/ p! I/ h9 ~$ n, w set my-phase -1" h+ K* _% B" r( d6 d `
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
" F* k6 @ \/ n# R ?7 ~8 a set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 s7 e! r% h T6 d$ X; f& F& S set intersections roads with6 `" h3 V; W! I( x$ `! M
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and4 r. o8 l c4 N' p$ }/ o7 ]8 e8 o( t
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 @+ [) n- V7 v1 X( o
7 r; _0 n# r& E2 W& [% R* m8 W; v ask roads [ set pcolor white ]
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end' F1 r8 d0 U9 }/ j# d9 I" g( H! \6 N* [
其中定义道路的句子,如下所示,是什么意思啊?: _4 c6 S% U8 s6 m1 r1 E% R
set roads patches with( H" \( u6 }- S& I0 |
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 Q& c7 n9 B7 ] (floor((pycor + max-pycor) mod grid-y-inc) = 0)]- ]8 H5 d0 ]7 @* e8 g" Z: a, _
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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