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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。
+ E% W& {4 p' T/ H+ h# pnetlogo自带的social science--traffic grid这一例子当中,
# m% b: ]! P, F& W. ~globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction0 J; d- e& M& x1 b8 M
grid-y-inc ;; the amount of patches in between two roads in the y direction
6 N: [ ^/ T: l3 K4 w% ? acceleration ;; the constant that controls how much a car speeds up or slows down by if' \' G( N/ s; L, T7 ]" ^' y5 Z
;; it is to accelerate or decelerate2 b- C3 R9 F- H( X8 \
phase ;; keeps track of the phase
! O* e8 k7 J6 h num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
, ^. v% l: e! A/ B8 x current-light ;; the currently selected light! a4 S3 _/ s0 s4 q, V7 w
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;; patch agentsets, G Q1 N; h/ ?+ F" F7 g; J; H
intersections ;; agentset containing the patches that are intersections
6 W3 t n, E. N3 M: X# ~. A roads ;; agentset containing the patches that are roads7 O) N- Z& H+ J& }4 H
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turtles-own
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1 Z/ d& r8 ~5 z) A2 \" K' c* ~ speed ;; the speed of the turtle
2 C" Y$ O9 Z9 x up-car? ;; true if the turtle moves downwards and false if it moves to the right2 k: k' M6 I4 H3 ?) @3 e
wait-time ;; the amount of time since the last time a turtle has moved+ ^. a9 y% i2 U% s2 d7 S5 ~
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patches-own
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' a) P% v( S- ^6 T% Y, n intersection? ;; true if the patch is at the intersection of two roads4 T% a3 b5 i6 n
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
( t* I: C8 n7 P9 M) ` ;; false for a non-intersection patches.
9 [: D# e: A6 o- | c* @5 c my-row ;; the row of the intersection counting from the upper left corner of the0 ^. y8 j6 J0 V
;; world. -1 for non-intersection patches.
5 L6 Z( ` R) K# d0 t c my-column ;; the column of the intersection counting from the upper left corner of the' g+ @1 n h- K2 l
;; world. -1 for non-intersection patches.
! t d- E6 Q# V1 x4 f# S3 U my-phase ;; the phase for the intersection. -1 for non-intersection patches.
& ^2 D1 H& {; w; ]6 i% \. { auto? ;; whether or not this intersection will switch automatically.
8 u6 ]0 y* }+ \3 u K! \9 P( y ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
3 j# l; h: B9 q;; Setup Procedures ;;( e1 p, A+ Z `: V7 w( r2 b
;;;;;;;;;;;;;;;;;;;;;;1 l% V2 Y& S) V$ c. e
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;; Initialize the display by giving the global and patch variables initial values.
. r: W: a7 Y, o4 j$ v9 ~6 c;; Create num-cars of turtles if there are enough road patches for one turtle to/ D* S& d! M- B9 Q3 P( _
;; be created per road patch. Set up the plots.
8 _0 Y' ]8 e/ O! uto setup% A" g7 d2 L5 |: R
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setup-globals' M3 d& I' R2 k
5 M) _- e" @. Y; R3 ]' B ;; First we ask the patches to draw themselves and set up a few variables \/ W c) h1 H3 e4 ?
setup-patches, r& K& f% h5 T2 q7 B
make-current one-of intersections' b* R: x0 u, J2 \' B% E
label-current
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set-default-shape turtles "car"
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7 g. C( m" z* {, g) s v$ L) p if (num-cars > count roads)4 |6 h. E- ~' }, B7 h8 N7 k
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user-message (word "There are too many cars for the amount of "
2 p' H7 ~3 G* {1 Z% z) j "road. Either increase the amount of roads "" o# x1 i3 [2 V; k6 G
"by increasing the GRID-SIZE-X or "
" M0 g$ K P) h4 N0 s g& `7 l. Q "GRID-SIZE-Y sliders, or decrease the "
$ b( U6 G' R8 N& {5 m) [9 ?$ N* |4 d "number of cars by lowering the NUMBER slider.\n"
- |, _2 O. Z) _: r "The setup has stopped.")+ H1 D4 K _$ R# g- ~2 R
stop! O; x3 j" t! e2 q
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) X' W( z3 i1 e" a. d& ] ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
2 `0 I" z6 d0 d& Q' Q; ]* T1 I; T crt num-cars% m! L; C8 Q/ E" P) f
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5 \3 \; @. g: w( J8 d( h- x setup-cars, V+ n4 P2 D+ |: Q* _# e- i& r. q' }
set-car-color
' b d$ t" r7 Z2 V2 u. C+ I record-data
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;; give the turtles an initial speed
1 W* @. c" H' i6 K ask turtles [ set-car-speed ]% k) ^, i4 X1 q; R6 E! d. A
3 _9 E* }9 ?1 m$ n5 O reset-ticks- R/ z; `$ {& n( U& {% [4 a4 X) l
end" E2 h+ @$ K' t' F; h4 i
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;; Initialize the global variables to appropriate values& h, Q V% y: |% D! a
to setup-globals5 l" P& x0 N+ y% B/ W4 L
set current-light nobody ;; just for now, since there are no lights yet
$ w b% e9 b- a: s: ^+ F9 m0 a set phase 0
3 a, t: S. [- ]. ` t7 o2 }& r set num-cars-stopped 0
$ Z! r& {6 `% R4 \9 ^; v set grid-x-inc world-width / grid-size-x) i+ G$ V3 S: b" ]6 W% F% C6 ]3 }
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- Q, v6 N# t _/ B
set acceleration 0.099/ k' U5 D& F& K) }: v1 {" }
end) @6 d& x) a0 W# A8 B0 G% x* \
+ f5 `' k0 i" X! O- M;; Make the patches have appropriate colors, set up the roads and intersections agentsets,6 v+ A7 Y# t$ U ^
;; and initialize the traffic lights to one setting4 _3 c$ {. G% H+ q$ X
to setup-patches
* [: j+ f) z. a. A& V, N# `/ c6 c ;; initialize the patch-owned variables and color the patches to a base-color( g# R7 m' p1 K0 O
ask patches
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5 F. }- j) f2 x' s set intersection? false
6 m) r: V0 |. J, b$ b" F* ] set auto? false
5 d& X g+ Z7 Z, v* d set green-light-up? true$ _" A$ {3 N4 ^4 X& c: A$ w! H
set my-row -1; F6 Q0 d- f$ u" s
set my-column -12 x* U" j e: x' I
set my-phase -1( X; H' E' p e& W# P8 D
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets" `/ S6 M& D$ k% D, W) v4 x; w7 q
set roads patches with1 Y' ]2 V" O: I* C
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! T$ | _9 P4 y$ s; u, Q
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 }+ B9 i$ ^) ?8 C+ m
set intersections roads with
) U" B0 ~1 V# L A; ~% v [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
5 d6 |$ ~# u" k% D# m (floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 M3 X. V' a$ ?6 j( m
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ask roads [ set pcolor white ]
# _( ^1 D, G& ] setup-intersections3 _4 _ s ~8 ?0 [
end3 h1 E$ ?: p" V" S5 ]
其中定义道路的句子,如下所示,是什么意思啊? u P: B' {. O8 j6 a
set roads patches with' U9 X* y# Z* Z2 W4 q/ P
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or4 ?, X8 K6 I) ?/ w
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ C( b+ p. Q) h* q8 b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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