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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' g) ?7 v' u, ^/ O
netlogo自带的social science--traffic grid这一例子当中,3 ~& ^9 ~4 S% M* I9 Q5 J* C6 }* z
globals
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8 f/ [! R, z8 ?& J+ F2 w. n2 b3 [: S grid-x-inc ;; the amount of patches in between two roads in the x direction
, ~) \0 x+ }* q+ @# o7 ? grid-y-inc ;; the amount of patches in between two roads in the y direction
8 p0 b7 i1 m) a% a$ _+ Y8 S$ m acceleration ;; the constant that controls how much a car speeds up or slows down by if
8 ]5 X0 j% H# R& W, S1 Q3 _ ;; it is to accelerate or decelerate* A W6 t$ ~* J3 P: T7 r
phase ;; keeps track of the phase
9 P/ N4 g2 L* a2 m8 S% O num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure" @ b+ c5 @& k7 K/ V
current-light ;; the currently selected light
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;; patch agentsets
1 t& W0 i! X9 D3 L7 K intersections ;; agentset containing the patches that are intersections$ C2 d/ L: ^7 {6 s6 I
roads ;; agentset containing the patches that are roads
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/ }2 v& \8 A4 R$ i4 r8 D3 `turtles-own
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speed ;; the speed of the turtle# y! _# ~0 w6 D$ L" {! i) W
up-car? ;; true if the turtle moves downwards and false if it moves to the right3 S; O% F% l) P% D, ~6 z4 ^" o
wait-time ;; the amount of time since the last time a turtle has moved p4 Z: ?, _+ A$ Q# [- G# d5 N. f
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patches-own* {! x) ~# f& @$ y
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intersection? ;; true if the patch is at the intersection of two roads _# V5 y9 N7 E
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
; b* d* R* ^3 _5 ]- B5 z! P* W0 t* W ;; false for a non-intersection patches.
# j a- v! }! r" b( Z% I my-row ;; the row of the intersection counting from the upper left corner of the
. C# u* \/ y1 S! r' U5 K ;; world. -1 for non-intersection patches.; Z) ^$ }0 O0 @7 G5 w/ l# \4 `. Z
my-column ;; the column of the intersection counting from the upper left corner of the
8 Q+ A+ T# k Y0 ?$ Y ;; world. -1 for non-intersection patches.
* v/ S, @6 I/ O2 o3 k# ~+ N my-phase ;; the phase for the intersection. -1 for non-intersection patches./ I& H3 o+ e, w
auto? ;; whether or not this intersection will switch automatically.
: _% E0 H1 J* Z" m7 l ;; false for non-intersection patches.
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. E& T0 R2 ~$ f. ?) q;;;;;;;;;;;;;;;;;;;;;;6 j3 @, c+ S& Q X8 B9 [. F( i' b
;; Setup Procedures ;;( m5 u- U1 V& E, z$ d
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
( L* j# g. G! F2 c;; Create num-cars of turtles if there are enough road patches for one turtle to
& @( F/ n6 l% P1 E) M# b;; be created per road patch. Set up the plots.' A, W2 }: Z" |5 }1 q3 L1 K
to setup u* R2 X: E) f2 ]) s* a$ W4 q
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setup-globals
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( _1 Y" w) |, m/ G2 n4 v; c ;; First we ask the patches to draw themselves and set up a few variables
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make-current one-of intersections
: q8 |/ e7 p/ A/ @/ i label-current
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( p5 a8 W1 w' V set-default-shape turtles "car"
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, s* F) V! x3 [ if (num-cars > count roads)
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6 E( [7 O f' t user-message (word "There are too many cars for the amount of "0 j* c1 t; z7 A% n+ m1 [8 E' l! e
"road. Either increase the amount of roads "* u6 D/ { j* b `: D
"by increasing the GRID-SIZE-X or "* Y5 i! o5 U/ i; B3 c
"GRID-SIZE-Y sliders, or decrease the "
z K& c) ?5 X( I "number of cars by lowering the NUMBER slider.\n"* J: C9 s3 K: C5 |, q% V& I
"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" }4 o" u8 @, v* B, @- H. `
crt num-cars
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setup-cars$ c3 U# {1 s- A- A7 g
set-car-color3 Q* W0 c3 D3 q, h3 H' y1 S
record-data( m3 {+ S& p# X5 c! S1 q
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;; give the turtles an initial speed
$ p ` t0 n; o7 z6 v/ b8 M& M7 T ask turtles [ set-car-speed ]& P5 ?$ a0 e+ U! b
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reset-ticks$ J2 ~) Q/ P* }; c
end
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;; Initialize the global variables to appropriate values
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! e! m6 ]8 X1 e0 I' N set current-light nobody ;; just for now, since there are no lights yet7 q" b% K% G) m3 D- l. V+ t [
set phase 0
) a: }3 d% e9 a! ~8 `5 o) z set num-cars-stopped 0- B; M, {# n5 s: w, s( d/ R
set grid-x-inc world-width / grid-size-x4 {! C8 E4 I( t8 i6 e
set grid-y-inc world-height / grid-size-y- X- c1 K" F! D2 ]5 H+ `
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary9 X% ^/ m% R& s' D4 l( p, S
set acceleration 0.099
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; ~, F* E+ ]4 t, P2 O;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
" K X8 i) h1 U3 {1 m+ i- b9 A;; and initialize the traffic lights to one setting: U& w. {8 O+ ]8 _1 a0 h( \
to setup-patches' D7 j0 J0 ]4 E
;; initialize the patch-owned variables and color the patches to a base-color
{" |8 d8 t4 z) B; i9 r/ o ask patches2 u& `# j, p1 W- g9 S4 x0 m0 G
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set intersection? false
$ p! J) O" L# I set auto? false0 ~' g0 L5 r/ N# ]. e0 p2 }
set green-light-up? true+ Y5 R& C7 h0 J o$ a6 \
set my-row -1
2 p/ O) f @" C# f: c: I set my-column -17 v4 z v! B6 u, N; P {
set my-phase -1
5 Q4 {& Z4 F. n! g+ [0 p, U set pcolor brown + 31 F: o5 Y5 p6 D6 M; s
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;; initialize the global variables that hold patch agentsets
. n% Y: `8 t) x+ t$ C0 ? set roads patches with
" a, R7 c# r% z4 ]& x* C [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
0 `) r4 k" `5 ?" K! o( I. k& K (floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ p' `* A. l. J7 J8 E
set intersections roads with
3 M* U$ a. {" i3 Y+ g6 c3 l0 F$ r* N [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
2 b1 y" c7 Q9 B* I% r& w% F! {8 Y, j (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]0 B) H G. h) |. \4 ]- ]& C% C. E
setup-intersections
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i: \. a6 s# w( ^8 g9 }其中定义道路的句子,如下所示,是什么意思啊?
. t7 t3 s. M/ o2 q0 b5 R set roads patches with
* q+ p5 d+ Q/ R- W [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or1 \( @: R' e* s8 K5 o
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ k/ ^! c2 C( q
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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