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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。6 ]7 R, `; W' }0 P8 C f
netlogo自带的social science--traffic grid这一例子当中,
9 P; d/ Z* y" e0 `globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
: @0 f# m! |7 _' I" B6 l grid-y-inc ;; the amount of patches in between two roads in the y direction
" m* z# P e5 ` acceleration ;; the constant that controls how much a car speeds up or slows down by if
3 A' r# g. t+ ? ;; it is to accelerate or decelerate+ R5 f* ?* g8 N1 h& G
phase ;; keeps track of the phase* M9 w4 U. K' q/ d3 v
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure& D4 O+ d$ n2 q6 W- i5 I' [6 P
current-light ;; the currently selected light b* N) J5 q$ [4 H
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;; patch agentsets
0 S% c& h4 E$ m$ j b intersections ;; agentset containing the patches that are intersections3 b8 E7 j# V( O8 d: T; d
roads ;; agentset containing the patches that are roads( Y( h5 v+ g7 U/ K7 ?/ d- T2 ~; I
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turtles-own. I; n5 E+ [+ i
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speed ;; the speed of the turtle4 d- s3 P' p2 h
up-car? ;; true if the turtle moves downwards and false if it moves to the right
4 u! i# L* l: }1 @& |1 @ wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
, t$ ~$ Y: g7 w/ T green-light-up? ;; true if the green light is above the intersection. otherwise, false.$ G; W/ q9 n) I. c
;; false for a non-intersection patches.
( x+ p' m z# ~% G; g2 q my-row ;; the row of the intersection counting from the upper left corner of the* V, T' N/ F1 M4 X A5 f) t
;; world. -1 for non-intersection patches.
9 K' C9 g7 n7 k' t% \. U5 Q j my-column ;; the column of the intersection counting from the upper left corner of the
6 R9 |9 M' g- S& w ;; world. -1 for non-intersection patches.8 t, K2 Z1 J. {$ H
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
* J- A( x3 n7 {- r auto? ;; whether or not this intersection will switch automatically.6 C9 M! e+ n8 A) C8 }: K
;; false for non-intersection patches.
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' c: Y, L. O9 t" z6 U0 k1 d1 c7 I;;;;;;;;;;;;;;;;;;;;;;
! h3 c2 K. F7 Y. ?) j* b& z# n;; Setup Procedures ;;
" {4 `" p. [; @/ x* @;;;;;;;;;;;;;;;;;;;;;;8 }5 s4 T1 V+ e
" F0 d I9 Q8 {4 z: u;; Initialize the display by giving the global and patch variables initial values.
A6 s' Y1 q% z/ s;; Create num-cars of turtles if there are enough road patches for one turtle to: Z' @# L J* b7 F" Q; I& j; E
;; be created per road patch. Set up the plots.6 a0 l4 ~; B, b) ?5 i8 R9 E
to setup4 Z) @) R8 M, p6 o6 w% z9 ^
ca
3 K% c. T/ ]* ^3 Z2 o; i% I setup-globals" F5 O8 i( G j
# q4 s& H0 w% A$ M ;; First we ask the patches to draw themselves and set up a few variables) B* H7 e' v7 S# j' R$ D; K
setup-patches
* f2 l# ?9 ]( N, A7 ]) m make-current one-of intersections
2 o; i, n. k, I1 S+ f label-current0 {3 Q' c; M2 Y6 b$ r+ i7 q5 a
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set-default-shape turtles "car"( j ?+ t+ z& Z: F- c7 r
: e j/ L- J& I6 ?- F+ N6 ~! m if (num-cars > count roads): a3 {: b8 G- O0 @% q/ v! d& G
[
0 `3 R% T: l' o; H3 O user-message (word "There are too many cars for the amount of "/ S9 _$ n% v; J @- _5 L
"road. Either increase the amount of roads "- @' V8 |( m/ {$ |
"by increasing the GRID-SIZE-X or "
5 l/ w2 n W- a4 {1 Y "GRID-SIZE-Y sliders, or decrease the "
/ x3 c' _8 H; w6 a/ P" v! a "number of cars by lowering the NUMBER slider.\n"* j7 x; T! {8 z
"The setup has stopped.")' Z3 i- K3 _2 V+ t% y& ]. Q8 n$ o
stop$ u% E/ l( ?8 X
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4 e; [9 U9 ?2 B) o/ Z ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color1 r0 @1 K4 M/ F. u! ~5 M4 J4 c0 D
crt num-cars8 q3 u$ ]3 _+ M; C
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setup-cars) a9 n6 J$ c8 m8 P2 O
set-car-color
3 f) `, u, }7 |/ c& V/ n( }. y' ? record-data8 v; `% z, O; n$ P. q1 Q. f* @
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1 l- K- I, p6 ]1 }! m ;; give the turtles an initial speed3 Y$ \) x* T, P j1 P4 D- M7 z G! ]
ask turtles [ set-car-speed ]
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/ d9 p3 [% s/ o9 a( }" P reset-ticks4 d% `( T# y) b2 h$ ^% U- M
end
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;; Initialize the global variables to appropriate values
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% R" Z" t# C1 W& U" d set current-light nobody ;; just for now, since there are no lights yet) r# H4 y1 C8 ~# Z2 m, n
set phase 0
3 Z3 J$ ]" R* { f3 P( Z7 e set num-cars-stopped 0) C0 T0 c/ \1 K2 P% k- n" M; a
set grid-x-inc world-width / grid-size-x, v! w" k% G/ g% B: y3 H+ q& A
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' j. ~. f! i' [3 ?# A! b5 h% a% u
set acceleration 0.099
3 R. I: M$ ]- n; _% D* o j& n! ~end- ?# O. M4 L( l
+ H2 |" I7 H. ~, p8 \( U/ m& V;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
! p, Y/ E/ k+ G5 M( X4 L- e5 l;; and initialize the traffic lights to one setting
, g$ K/ F7 w) S, zto setup-patches
0 ^0 P; {" L. |$ D ;; initialize the patch-owned variables and color the patches to a base-color" v, d6 q& \3 U- E6 Y9 z
ask patches
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( I$ y+ k% M/ c; f0 N' g- ~" q set intersection? false; c7 C* A* N9 A# c5 V% m
set auto? false1 k. @' y3 s* t1 j) {
set green-light-up? true
6 W3 q' E- |$ _' I( c. @ set my-row -1
3 L. g9 P9 `& T3 K( W1 K set my-column -17 _' ~1 D( A8 H* C1 K o
set my-phase -1$ i+ t' t& X9 g4 p$ @+ \1 F$ U1 P
set pcolor brown + 3 X! r! u) M, I9 a
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;; initialize the global variables that hold patch agentsets
1 s0 ]. I( L" p+ B& k8 V. [! R: H set roads patches with2 j, w4 e, D( @1 ]" D& [. I$ u2 l4 \. |: h
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# B7 A1 \% B2 L3 a: O8 T2 q& w (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; M/ D0 Z$ j5 H$ r* w
set intersections roads with2 b% M) n1 I5 `' P3 D
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and( L \4 C+ C/ h
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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; `5 ^6 r9 s/ H% I/ w ask roads [ set pcolor white ]
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% S$ S- ^8 o$ k. `其中定义道路的句子,如下所示,是什么意思啊?7 }: u8 `9 ]. K
set roads patches with" G+ ?( i. J/ ~6 w- {2 U7 _0 t! ^$ _
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
) X6 [: r! O& G4 B (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 J1 W9 s' F) T2 d& 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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