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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。
- A" ^, f* f* z6 \# ?$ Mnetlogo自带的social science--traffic grid这一例子当中,
) L& L ~& O- ?' Nglobals, Y2 R9 m8 Z8 n$ I3 I6 O2 ?
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grid-x-inc ;; the amount of patches in between two roads in the x direction
2 [2 w5 o" T/ h/ I5 } grid-y-inc ;; the amount of patches in between two roads in the y direction
' N% k$ d5 f: R" d& O4 h acceleration ;; the constant that controls how much a car speeds up or slows down by if
2 E# E4 N- j) u' f/ F( R ;; it is to accelerate or decelerate
9 a. s, C0 {6 O" g% P phase ;; keeps track of the phase
; n: n/ m0 P) V$ y num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure' ~! d- H0 t3 e3 u0 T9 x
current-light ;; the currently selected light
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;; patch agentsets( E' W [' w5 J7 K; |
intersections ;; agentset containing the patches that are intersections
/ r! x+ |) j1 m9 o roads ;; agentset containing the patches that are roads
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turtles-own
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& F' v# L' Y) Z8 V. i. ` speed ;; the speed of the turtle
8 | [5 R2 z. v( \5 @+ W up-car? ;; true if the turtle moves downwards and false if it moves to the right) C2 s- F8 q; c
wait-time ;; the amount of time since the last time a turtle has moved
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1 C$ H4 h. V; ]$ Q2 opatches-own
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intersection? ;; true if the patch is at the intersection of two roads$ `, {( i8 g1 a% b7 h n
green-light-up? ;; true if the green light is above the intersection. otherwise, false., B0 o+ K3 c, b% y9 \5 C# D
;; false for a non-intersection patches.
* `- x) Z' L# @( I2 _" W$ l my-row ;; the row of the intersection counting from the upper left corner of the& o. v# J5 U9 W8 F. ~
;; world. -1 for non-intersection patches.' E9 U. _3 x$ X: J* i/ F9 r/ Y! g' T
my-column ;; the column of the intersection counting from the upper left corner of the$ P3 m: T, G% u7 u9 g, z7 ?
;; world. -1 for non-intersection patches.5 n# A7 i9 T$ I% C& S! l
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
, J% |! r: J& c9 B auto? ;; whether or not this intersection will switch automatically.9 I8 i, I- h4 ^ L" Q
;; false for non-intersection patches.! P7 S% @/ R2 d$ _0 Y4 A
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6 o% V" g( I h, U5 K2 p( Z; T;;;;;;;;;;;;;;;;;;;;;;
6 F/ B5 `6 y9 \" w7 k;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values., F( m9 ]6 L5 y, J- J# J
;; Create num-cars of turtles if there are enough road patches for one turtle to
5 J9 O) c0 ~' S0 J6 T4 P$ o5 R2 ?;; be created per road patch. Set up the plots.
* f& C1 v9 K4 I3 Y# e& b8 gto setup) b) U% S9 q; {, V
ca
2 r1 g* P. M1 }4 p: w- w- e setup-globals
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0 a% _# E, `$ L; z/ {& I ;; First we ask the patches to draw themselves and set up a few variables% Y& O* l* ^6 E, ?2 t; m1 j! O& O
setup-patches
3 e) g* d# i# r- D% ^ make-current one-of intersections' K# \0 a: l" O/ l i
label-current2 |: Q5 N6 f( i( m
, K! a# r, J1 J: U0 D set-default-shape turtles "car"
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if (num-cars > count roads)# ~- ^6 B8 U8 U
[
8 a7 h. o" F* X: d user-message (word "There are too many cars for the amount of "0 n( m, d2 c3 q0 G! R+ v: V: r" ]
"road. Either increase the amount of roads "
- F! O. B# s$ t7 e; C5 u1 C' d "by increasing the GRID-SIZE-X or "
$ g0 N8 p$ ]( [6 U: u" ^. p "GRID-SIZE-Y sliders, or decrease the "9 O8 |. }/ S, A- Q
"number of cars by lowering the NUMBER slider.\n"
3 F9 |& _: M6 @' O8 @3 n "The setup has stopped.")) y& V- I s" ]- q4 m4 h8 a1 X; e
stop$ i! R% c. C& k9 b% U
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color* v+ C1 ]9 m7 g9 l H
crt num-cars) H1 o2 P3 O5 b* ^3 n! R4 y8 m
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setup-cars
1 a0 b; `! |9 E( n. g9 d: p* } set-car-color. k, r) f/ ?: K- Q! n% ~
record-data6 }$ Z; J, ^/ v# ] g* p
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;; give the turtles an initial speed
1 U- _7 q0 H" S7 r ask turtles [ set-car-speed ]
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' m0 u: F- b$ ~; k) [7 I; k reset-ticks" P8 Y+ y, X3 S' V
end
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# o( l2 Y7 ]. q9 ]3 c;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
& P1 Q6 u5 }; b X9 {; F set phase 0
8 f x% K( K: ?' a9 z5 y5 e) U8 L set num-cars-stopped 0
6 m# i4 ~+ V% p! l& t3 m( w5 C$ L set grid-x-inc world-width / grid-size-x
5 I5 ^3 C/ u/ C, h set grid-y-inc world-height / grid-size-y$ D+ L8 [& X+ d" o7 S( v
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
% e$ ]3 w* Y* T, X8 R9 E set acceleration 0.099
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8 c( p0 ^+ ~& p& i% h6 b+ t;; Make the patches have appropriate colors, set up the roads and intersections agentsets," y$ o) K# R0 n" c$ z
;; and initialize the traffic lights to one setting
5 b3 @0 o2 \9 E3 d3 y& }. _to setup-patches
, w( t q1 k' e$ U( v ;; initialize the patch-owned variables and color the patches to a base-color
x/ v) T5 E9 {) h ask patches
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* {' ~# I, B! V* G. w# f set intersection? false
9 n) z f5 E, z( d, m) n" \- E set auto? false4 I: X% j- c# m8 h, u5 V5 z. V' _
set green-light-up? true
2 h2 Z' y& s- `0 E( W& H' } set my-row -1
9 ~7 B3 V! b( t; t9 q set my-column -1- H1 t& y9 X. M( F* @% h
set my-phase -18 L0 A! Q2 j o
set pcolor brown + 30 t; R9 _2 d0 H" F/ W/ j* B, C' F
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;; initialize the global variables that hold patch agentsets
k' Y6 y/ ?. E6 ~# v set roads patches with
& d/ I" V2 |( x3 ?, z2 } [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or. ^2 I! R3 S7 E0 r% L p( s
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; ?! I( ^8 b( D! z, s set intersections roads with& E j o2 _7 `+ ~
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and% F6 F- @! \' U# I4 `/ M
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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其中定义道路的句子,如下所示,是什么意思啊?6 T1 ]: Y7 t. }. U
set roads patches with" \! W# j; P( g; N% }/ L
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
% W( n+ R4 s- h, S (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 j$ C: Z# p0 P2 x* V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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