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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# _& v, f, a- |netlogo自带的social science--traffic grid这一例子当中,
7 @4 C+ \# c; w$ f! Z/ \' _globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction V, l7 v `: F0 C
grid-y-inc ;; the amount of patches in between two roads in the y direction7 r# N$ z* V, X$ s6 @
acceleration ;; the constant that controls how much a car speeds up or slows down by if
( |: T' ^4 e+ l- i, W. K& t ;; it is to accelerate or decelerate6 N( l4 B- v' U, j* \% [
phase ;; keeps track of the phase
- d2 K/ e2 p9 f num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
, @3 K" _+ V5 t current-light ;; the currently selected light6 J2 c$ P8 u3 y3 U* [ E; {
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;; patch agentsets; a1 ]# `, D5 }/ M7 A3 Z
intersections ;; agentset containing the patches that are intersections9 T) H& k) f+ f/ w9 n
roads ;; agentset containing the patches that are roads
5 `. U& B( [- j/ G2 a x% B]
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. ?1 M. ^2 I) `% s, dturtles-own7 J$ j5 F2 S) x( ^& \
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speed ;; the speed of the turtle
) i u+ @+ H2 H% s0 G0 h/ R up-car? ;; true if the turtle moves downwards and false if it moves to the right
$ r6 e- x: u. F1 W wait-time ;; the amount of time since the last time a turtle has moved
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: J' @, A2 d8 lpatches-own
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+ J ^% M( q( b) V% e9 a9 F& f intersection? ;; true if the patch is at the intersection of two roads
# E* ~- W9 P2 O9 E' U9 [6 b5 s green-light-up? ;; true if the green light is above the intersection. otherwise, false.* B/ J5 ]4 a3 E+ U x/ m6 f
;; false for a non-intersection patches., M" H, ~: |. f. _5 `5 g3 i- y
my-row ;; the row of the intersection counting from the upper left corner of the
! ?* `% E9 C" e8 N; L7 B ;; world. -1 for non-intersection patches./ w: y' O: e; Y( v1 e+ z* n! g
my-column ;; the column of the intersection counting from the upper left corner of the+ c: B6 U4 ~$ Q6 e2 u
;; world. -1 for non-intersection patches.$ o0 _: e. y* e- u. J
my-phase ;; the phase for the intersection. -1 for non-intersection patches.% F/ E( U3 x' h4 ?) s4 q8 c( R
auto? ;; whether or not this intersection will switch automatically.
& n4 p' p% h$ @5 q8 g" t; { ;; false for non-intersection patches.. [! f' [+ T0 Z
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;;;;;;;;;;;;;;;;;;;;;;( g+ W9 Q2 [ [- \$ X1 ?* C
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
$ m) W# r% b& e5 p; D: x;; Create num-cars of turtles if there are enough road patches for one turtle to
: z- t+ _( B) W! z5 T0 U5 }5 W* `) w;; be created per road patch. Set up the plots.
i3 | W2 C! ]# N3 F, Rto setup( ^% ^ a2 h$ g5 H. c# E4 v5 `
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables! t; P, j+ g( c2 N+ C& H: Y8 y
setup-patches
4 @# w. s6 E1 r7 ?) u make-current one-of intersections9 y% {* d6 b% e6 _( l: d8 O" v7 D
label-current8 n: H5 ?/ m8 {1 K' b. k7 S' H
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set-default-shape turtles "car") ~) i& s6 h0 p. e; o% T- F: R5 J& D+ ^
* Y1 g4 y; H! l4 t if (num-cars > count roads)! v, f/ l# V5 S6 P" a0 R
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user-message (word "There are too many cars for the amount of "3 ?0 ]$ h' V4 }" T' j( v
"road. Either increase the amount of roads "
/ \# w! ]3 f* G* S! S( B "by increasing the GRID-SIZE-X or "
9 A ^$ c. Q, b! [) W7 U "GRID-SIZE-Y sliders, or decrease the "
: ~( j. n8 C" x8 W) P- K "number of cars by lowering the NUMBER slider.\n". K8 g: X( m; S$ v4 ^
"The setup has stopped.")
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; r7 ~6 B, S1 j9 e ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
- r9 s+ l3 u& w) U( C# }3 N" ~ crt num-cars
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7 I* \" P, e' ?8 C& ^( u( ~- a setup-cars
; C, |) f9 \9 z7 U' u set-car-color& ^: ?. ^8 K( E! U% B a' a9 H& _/ F
record-data* F/ R* A) ^ j! ^- B; h( b
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) g1 ^- R" J' _; G! x5 A8 K ;; give the turtles an initial speed$ l% F0 Q# U5 u9 ` E# m5 I
ask turtles [ set-car-speed ]
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reset-ticks& y0 W5 Z8 f3 C1 b; D/ ]) |
end: f- }0 b9 S) j W1 X7 \
! ?& p- T# [" T7 h' ]+ @) r- Y;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet) b+ A' | h4 l5 X. M5 B
set phase 0
4 P9 N' K. }0 p set num-cars-stopped 0
# e( ?* }. L/ d; o, a/ \- K6 N& w0 x set grid-x-inc world-width / grid-size-x) O8 Q7 ?6 r d5 A0 S8 q3 w
set grid-y-inc world-height / grid-size-y
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( }: K \! u* m. d, w' Y& Q ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary: s3 g0 q" V3 J7 i5 q& J3 t& G
set acceleration 0.099
& o' m# v9 l: p0 ]- Xend, S( `4 c, W$ \4 ^5 Y
1 _0 x$ |/ b5 I: I5 a, d5 {% `;; Make the patches have appropriate colors, set up the roads and intersections agentsets,+ S/ Z' O% B6 e) l7 _( P' L6 [5 X. J
;; and initialize the traffic lights to one setting; N9 r5 s+ g3 W3 T( g* v: s
to setup-patches3 A. j1 C; h9 ?: ~& L
;; initialize the patch-owned variables and color the patches to a base-color
7 ]7 I7 v* V9 l9 w: V: p: K5 S# B3 R ask patches
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W; s/ K( T1 E% y set intersection? false+ k! `! a1 z8 _) `+ T( ^1 \4 J% C
set auto? false
* F# E5 h- v5 ~2 Y4 O set green-light-up? true
F C: K5 o _$ b set my-row -10 p+ d0 ]2 C1 G0 s, O" j* ]6 m, Z! e
set my-column -1" f3 U# x# ?0 o+ l
set my-phase -16 s* R f1 S& n
set pcolor brown + 3. q( Z0 ?% D2 E1 }: O
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;; initialize the global variables that hold patch agentsets
# W; S! x9 i0 N* t; V set roads patches with
' U! r7 j# c7 S. v# Y* L3 R. j [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
( g8 ~: y8 h) C8 ]4 z. j3 b/ ? (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, M! l4 @$ @7 A* {4 X set intersections roads with9 z; B+ @& B' E, c. F, p; F! ]
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
4 [, b2 K* J0 \5 Q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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2 ?* d/ q$ Q) Y ask roads [ set pcolor white ]
3 L( |5 S) K, ^0 V, I1 K: e setup-intersections
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* r) x: \8 V% P9 B其中定义道路的句子,如下所示,是什么意思啊?* C, `9 s( i4 I4 Y( u
set roads patches with8 y, c5 N; t) ~. [& W8 k
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or3 ]7 Q$ C6 J. T
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
l# p$ j) K2 G7 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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