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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。2 @( ^2 r+ E7 A% g5 B9 i: G/ m
netlogo自带的social science--traffic grid这一例子当中,
8 h; g/ |( e0 R8 Y: r( `. ]globals1 R& J% v9 i( ?# ?- d
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grid-x-inc ;; the amount of patches in between two roads in the x direction
5 p1 K5 U7 B( O( c grid-y-inc ;; the amount of patches in between two roads in the y direction* X7 N9 X' f( a ~: l/ ^/ }
acceleration ;; the constant that controls how much a car speeds up or slows down by if
! p; g$ @ | S w" l! H ;; it is to accelerate or decelerate# B3 ^* g* E( i1 K' i; B( h
phase ;; keeps track of the phase
, Q$ M ^# R s, i& g num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure' h* f% x% V) V1 h" v
current-light ;; the currently selected light; D2 T9 c; `* E- N4 w& Z
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;; patch agentsets
* N* @" q0 T0 e$ Y0 { intersections ;; agentset containing the patches that are intersections
: g" J% s; m; B( s4 t roads ;; agentset containing the patches that are roads) o U9 ]( n8 k, L* Z, n
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turtles-own
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7 n, }# U$ i% P* V speed ;; the speed of the turtle
$ z9 P" _/ q. s$ t up-car? ;; true if the turtle moves downwards and false if it moves to the right( V3 R u; F4 q" L1 j
wait-time ;; the amount of time since the last time a turtle has moved
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5 O7 W+ q, z7 l3 r2 Jpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
, Y/ i" s. }" M% _ green-light-up? ;; true if the green light is above the intersection. otherwise, false.. n" Q: A- P2 G+ a; K0 I% Y& h
;; false for a non-intersection patches.
/ [/ w7 R7 Y8 }8 L" b( s0 W$ J. G my-row ;; the row of the intersection counting from the upper left corner of the
8 o4 {( q' ], X& f% a ;; world. -1 for non-intersection patches.
9 s# R) L* P( T# [- c my-column ;; the column of the intersection counting from the upper left corner of the: T8 ^0 F4 P; u# ?' n6 w' l+ |
;; world. -1 for non-intersection patches.
9 J4 Y" M- z% D- Z7 h0 q my-phase ;; the phase for the intersection. -1 for non-intersection patches.! y/ D3 a3 m! F' y% T1 p
auto? ;; whether or not this intersection will switch automatically.
4 U. s* G1 Y* @5 f2 {) | ;; false for non-intersection patches.2 R# j: i% q h1 I1 t: I
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: S( \9 c- I$ V& w# I;;;;;;;;;;;;;;;;;;;;;;' X: }$ c" X' _. R
;; Setup Procedures ;;) j2 X! F. e3 R
;;;;;;;;;;;;;;;;;;;;;;
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; r1 W* N7 c; p. X% b- J! D2 [0 ]. I;; Initialize the display by giving the global and patch variables initial values.
* s$ M: f/ @! }+ g" X# a+ D;; Create num-cars of turtles if there are enough road patches for one turtle to7 u. u/ _* ^6 R& R( f' a+ t
;; be created per road patch. Set up the plots.2 w3 y7 t% d8 ?7 ]# J5 q
to setup; A' y7 T v8 d7 _# t9 D3 c
ca
$ q" X! M3 S' I. u6 x- I setup-globals( A3 m6 a" y+ U* a' j& ?2 i
# b( d. o- d6 H5 e ;; First we ask the patches to draw themselves and set up a few variables0 L2 ~7 K# L9 ]% X2 z; l
setup-patches' E' d# R4 _$ K c; T8 K p
make-current one-of intersections
_2 D* K. ]- G) T label-current
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set-default-shape turtles "car". E# W$ A s& s" E0 Q) l3 k
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if (num-cars > count roads)
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/ R$ G" T( {3 {& a( B( N user-message (word "There are too many cars for the amount of "
H5 |" h* f P, r* ^ "road. Either increase the amount of roads "
3 |' o& q4 b5 h/ l "by increasing the GRID-SIZE-X or "$ G$ t" r: \* j' Q! f" T4 e
"GRID-SIZE-Y sliders, or decrease the "
; b4 a/ D/ x7 i1 [ "number of cars by lowering the NUMBER slider.\n"
8 p9 r f+ }# Q' p4 @: s9 u "The setup has stopped.")5 ~1 I, @8 P& l% M4 L( N
stop
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% {% F+ b3 V k5 D3 K) P" K: j ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
6 s. E$ ]: B" N& c% i) l crt num-cars/ d) D) l* f7 V' t8 B' Y
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setup-cars
% W" |2 Y! V3 y r; H# l set-car-color# t7 _, X/ g r/ K% L
record-data+ Q5 i7 @! a7 w+ L, G3 M) N0 P+ T
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;; give the turtles an initial speed. W; E. u6 ]. C y7 p
ask turtles [ set-car-speed ]
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reset-ticks9 U6 w; y1 e* C+ V% h. T' L
end
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;; Initialize the global variables to appropriate values
' Y2 q) X; C+ gto setup-globals g( l4 U6 R" Q* a$ Y
set current-light nobody ;; just for now, since there are no lights yet
" W: a* N; L9 [- X8 f: _3 D set phase 0
o, s6 T8 e- T- O& O; P% ~4 A set num-cars-stopped 0; [2 e! {$ O6 b- q6 `
set grid-x-inc world-width / grid-size-x' v4 M, \1 \: m
set grid-y-inc world-height / grid-size-y1 k- t' j0 {9 ?, j% U& T/ J
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
2 }5 A7 l( z% E- p# I( i set acceleration 0.099
M7 n) S/ U. m5 T. iend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
- B* w: }( r3 c3 v' K;; and initialize the traffic lights to one setting
2 n3 C2 V' t+ O) Bto setup-patches' w* e. L6 Y* o
;; initialize the patch-owned variables and color the patches to a base-color
8 C0 i% W, y- }8 l; j ask patches
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set intersection? false) E5 T+ R3 i6 G9 t
set auto? false7 R1 F, s5 K" f/ Z8 B
set green-light-up? true0 x3 l/ j3 y1 t8 A; D
set my-row -1
7 a$ j: @+ y# x+ z set my-column -1
% `( ]6 r# q! a set my-phase -1
+ y) y0 p( o% N: A$ F: O1 G- }2 | set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets! d7 m3 d& l% ^( t
set roads patches with' Q' M. |; z l, _; ?. X
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
) B- v d' N. J) D/ H$ A+ G' C$ ~ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' _3 r" [4 `% N% B7 s set intersections roads with
& U; p+ _: z3 n" z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
! u4 @2 c# u7 n' x) H- a* t( V' Y, L. E (floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 I. e6 D0 q1 j" d
8 g2 i& t: p. H. u3 z" ` ask roads [ set pcolor white ]2 a6 G. R" z; v; U1 |# a* S
setup-intersections& ]9 e v! [+ `2 _! y" P! q
end4 p V% ?, R+ w, T' C8 A3 ~- H
其中定义道路的句子,如下所示,是什么意思啊?
/ H% [$ K; w D. x set roads patches with5 j% I! h- r; j) ~7 ?/ H: d" m
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 h7 Q4 _( \3 y) t6 j% Y6 w (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
4 _* V! ?* U$ j3 B2 s# Y7 K- d$ F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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