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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。$ Y, \# M( d9 h& t
netlogo自带的social science--traffic grid这一例子当中,$ {7 p9 w$ i) X# N8 S
globals
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9 E! R9 `" ~: T) Z& v grid-x-inc ;; the amount of patches in between two roads in the x direction0 p: \- J% y3 h8 V! Y# N; E$ w
grid-y-inc ;; the amount of patches in between two roads in the y direction
8 M: v2 }' N4 q! b2 x! L) @6 h acceleration ;; the constant that controls how much a car speeds up or slows down by if6 [+ Z+ |3 A' i* O9 R8 O: q& n! t
;; it is to accelerate or decelerate
& @" r7 G' |+ B9 L7 z phase ;; keeps track of the phase9 T% i% p9 W4 B( ]1 B. h+ d* b+ N
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure/ \! { G" @6 X' V. W, g, x0 [
current-light ;; the currently selected light( y% g+ w. o. i( a( m/ U
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;; patch agentsets) Q1 M' c! V6 K( u
intersections ;; agentset containing the patches that are intersections
. v$ D! C2 l. A5 Z8 I, \4 S& F/ z" | roads ;; agentset containing the patches that are roads
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. g0 \1 f, G6 ~7 `/ K5 Qturtles-own; }' ~& g, E R2 q
[
0 g) h( R* o. \/ l/ e speed ;; the speed of the turtle/ B& r3 u9 n3 u8 ~! ]
up-car? ;; true if the turtle moves downwards and false if it moves to the right% G' L2 i7 e: S t' Z. L
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own6 C4 j( u- u7 l- x% P/ B( k9 y% W
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intersection? ;; true if the patch is at the intersection of two roads) T t+ P" `. Z9 K
green-light-up? ;; true if the green light is above the intersection. otherwise, false." Z3 W9 l0 w8 i* {
;; false for a non-intersection patches.
+ x( b3 d5 J4 I c1 u0 t# j my-row ;; the row of the intersection counting from the upper left corner of the
# R7 ~3 F+ P/ r. k1 {0 P& I! U4 P# ] ;; world. -1 for non-intersection patches." R% g& F4 ` U1 M8 B" c: p: T" w
my-column ;; the column of the intersection counting from the upper left corner of the
- ^# L( W1 X h' {% l$ j8 [ ;; world. -1 for non-intersection patches.3 C9 m6 e- \0 S. F
my-phase ;; the phase for the intersection. -1 for non-intersection patches., s2 z$ \8 O! t# |1 {6 a) v
auto? ;; whether or not this intersection will switch automatically.' z0 o4 [9 |7 p8 r; }3 d
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
1 X! Q0 U N8 v) F5 m2 [* e- n;; Setup Procedures ;;
5 W e3 k- d$ p% F;;;;;;;;;;;;;;;;;;;;;;
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z+ Z# F: N. l9 S* ~5 J;; Initialize the display by giving the global and patch variables initial values.
, P: [1 j) i! v;; Create num-cars of turtles if there are enough road patches for one turtle to. u8 s! Y3 D3 _6 g
;; be created per road patch. Set up the plots.
0 [( g( t; `/ b+ l1 c! qto setup9 S6 Q5 G" e3 p L2 m# ~
ca
8 l$ l0 J! m3 w setup-globals% l* I+ |) {% o8 C. H
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;; First we ask the patches to draw themselves and set up a few variables
$ Z7 I1 k0 I6 i# P q$ q; {7 ?* ` N9 Z setup-patches( R6 A1 @8 h( z2 s; n2 l9 S( f3 o
make-current one-of intersections- \! S1 w1 Y7 B- `
label-current4 N! ^+ ?- ^% M4 ^
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set-default-shape turtles "car"
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if (num-cars > count roads)
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1 q; d- [% i* x: q3 ] user-message (word "There are too many cars for the amount of "
# h: p' @" ~" S9 Q "road. Either increase the amount of roads "
9 [# W7 r" ^" {" y9 } "by increasing the GRID-SIZE-X or "
6 Y' T3 h/ F) Q' U# l "GRID-SIZE-Y sliders, or decrease the "# T0 k$ I3 X- J+ R
"number of cars by lowering the NUMBER slider.\n"
* u7 o" B6 [8 ^ ~ "The setup has stopped.")
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]
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
4 s# d3 X# j$ E1 `" h1 Q$ V crt num-cars: @7 V2 I' U- {( e& v; d/ B
[
8 [( p! P+ G+ c | B setup-cars% w' |0 `- T. `7 B
set-car-color
' `! i2 H0 K$ R$ x record-data
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1 F7 ?3 J- d4 m. z: w ;; give the turtles an initial speed4 h* l4 |9 z, n: ?7 l
ask turtles [ set-car-speed ], p& f2 j" e j* J2 a0 s6 h( T
. ~5 W9 ?0 j; ]0 h reset-ticks5 S [' w( ?5 }+ e+ ~/ x
end% B# I5 O. x* v! p& l
" J) O1 O- g7 m;; Initialize the global variables to appropriate values
8 A+ e. g! j, a$ c3 Oto setup-globals
6 s* a- s) Q1 Q9 t$ c' | set current-light nobody ;; just for now, since there are no lights yet
7 |# @& |9 \9 X: K set phase 07 D" D( |1 Z. l, m. t
set num-cars-stopped 0- |& O5 t% c# H# L. C
set grid-x-inc world-width / grid-size-x
- ^6 V5 s: N' Z) ^$ }4 I% _6 s 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 boundary2 T7 {$ a+ x/ D& K" d8 I
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,7 i6 p0 ]6 o# a; U' K& k$ z1 B- P
;; and initialize the traffic lights to one setting
2 p( {6 u' M% o+ F& Yto setup-patches
, C: `& n* D$ w. W* a% I2 X ;; initialize the patch-owned variables and color the patches to a base-color
# d9 ^; v; i. z: o ask patches
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9 o, u8 V- o& J) U3 V5 x set intersection? false
5 c1 Q' G% t1 k) ~2 h set auto? false7 x/ i. b7 K: V S* O
set green-light-up? true
1 d' O2 `7 n. L, F8 ~ set my-row -1+ A' K; V* |5 \" z
set my-column -10 K- n- i; v8 @) I% f8 v
set my-phase -1
; D( D' b ~' r set pcolor brown + 3
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4 c0 ]3 x1 B( g9 C9 Q ;; initialize the global variables that hold patch agentsets5 l7 q5 W1 I% ?- N' H3 ^
set roads patches with
T- q3 ~ ^3 `' Y+ s! V W [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or# C( W% h" V2 ~+ i) c
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]- A: G9 v! m8 @1 V; e
set intersections roads with, S8 C5 D# {' w( r
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and& s# h- u4 A& u c$ T
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]) D0 N% U$ N8 ]; O
setup-intersections: |' _. q# s/ Q3 a$ p* r
end5 D( {5 p+ a F$ w, u. a
其中定义道路的句子,如下所示,是什么意思啊?7 S4 T- W" u7 R$ R s1 N
set roads patches with4 P: E/ V/ n6 B) Y0 u/ q3 Y
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, @8 r0 u# z3 B& `( b
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
& } y' ~! P7 ^' T; T* h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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