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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。
" ] I% ?5 d/ l$ ^6 f2 m& I/ I$ vnetlogo自带的social science--traffic grid这一例子当中,1 S. u3 q3 |" `" J
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
, u$ z% S: ?/ k8 r! L grid-y-inc ;; the amount of patches in between two roads in the y direction
5 @' q% ?# X; T* }9 l. P acceleration ;; the constant that controls how much a car speeds up or slows down by if5 u0 S' H: c( `0 o
;; it is to accelerate or decelerate
2 M, T& e, i1 M) Y5 ]& D phase ;; keeps track of the phase
$ @6 H/ T; w/ O% J num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure" H9 H( D- r# X" O; N4 R# f: D
current-light ;; the currently selected light
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$ k; t, g9 J0 Y# Q$ a; }, ?: ^ ;; patch agentsets+ d! `6 W# a1 C7 v& A+ M
intersections ;; agentset containing the patches that are intersections
" s+ p* _. \2 `4 a; N$ i5 p roads ;; agentset containing the patches that are roads
Q' e( y1 T6 w* f, |# }2 x) []
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7 H) M# k' R+ G5 Y/ M7 M" ]1 Jturtles-own
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speed ;; the speed of the turtle
$ S* _6 l- m+ [% r/ T up-car? ;; true if the turtle moves downwards and false if it moves to the right
+ C5 _4 a: E' J7 W wait-time ;; the amount of time since the last time a turtle has moved% [3 m8 h* N ` E
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& Y' T: s+ |( v9 v+ }1 O$ kpatches-own( Y0 O0 v- J/ o6 {* i
[
9 N4 I/ ?. `4 l0 c- }( X. ?' X: ` intersection? ;; true if the patch is at the intersection of two roads
% ]$ ]4 _2 l) g( L1 \7 o* p- T9 W7 X green-light-up? ;; true if the green light is above the intersection. otherwise, false.
( b! x5 S; E6 [; X2 h% ?+ ] ;; false for a non-intersection patches.
; Z) F1 ^$ p9 J9 ? my-row ;; the row of the intersection counting from the upper left corner of the
4 a' z- N H3 z7 ?) y ;; world. -1 for non-intersection patches.% |9 n0 p9 O& F; W
my-column ;; the column of the intersection counting from the upper left corner of the
# F+ r& M6 z9 p; p& z8 \% x ;; world. -1 for non-intersection patches.( P" J0 S; M- z+ R1 p' i
my-phase ;; the phase for the intersection. -1 for non-intersection patches.$ a$ v0 a+ ~! U! H
auto? ;; whether or not this intersection will switch automatically.6 k/ K: T' }9 P; h; c
;; false for non-intersection patches.# T$ ~+ t p0 k. X( x
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. ]5 @$ D4 N' k) u) n+ f9 O;;;;;;;;;;;;;;;;;;;;;;
7 Q; M* g( E- [# k0 }* N1 X;; Setup Procedures ;;2 |% Q% P% J. ]6 Q
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values. [" ?2 T0 i6 C
;; Create num-cars of turtles if there are enough road patches for one turtle to
0 Z" T* t7 q6 i;; be created per road patch. Set up the plots.% I, O+ I2 a* A" D' [+ ]
to setup
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setup-globals
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o$ ]0 y3 x) X: f( [1 w ;; First we ask the patches to draw themselves and set up a few variables
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make-current one-of intersections
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set-default-shape turtles "car"
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "' T2 n, Z$ H% `0 T* D
"road. Either increase the amount of roads "8 i; d/ A# N% \7 M$ E2 z
"by increasing the GRID-SIZE-X or "
7 H" o/ z$ ^7 G; M9 o6 T2 ] "GRID-SIZE-Y sliders, or decrease the "
* ^- V- `) |# x "number of cars by lowering the NUMBER slider.\n"4 O7 ? m9 P+ }, T8 l& Z
"The setup has stopped.")' {; ]7 I9 m& U$ r! Y$ W
stop
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' q# P) S1 ~: Y$ J: @1 Q( p ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
+ d+ u! _2 F; E# z, N' E# b1 w! Z3 q crt num-cars( M* K- U# I% c; S; F8 _2 [3 L
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setup-cars; t* \$ r6 Y, T" U6 D1 g% f
set-car-color+ |- q+ a ]& Y; a! T7 _
record-data5 [& r+ A; ~ h1 ?/ j, Z
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: v5 W5 l8 v3 m O2 m ;; give the turtles an initial speed
, T- b J& B+ @" p2 { ask turtles [ set-car-speed ]" ?, _/ h+ i( Q- q5 ]3 P7 z! u# }* C
% D2 p4 w/ @" x+ Y* U2 E reset-ticks6 J7 p: N- ^ @3 K+ v& r% {. n) _
end
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0 s! n3 f$ y% P+ q) Q2 E;; Initialize the global variables to appropriate values' [4 ~& ], f1 N$ w9 a
to setup-globals# u) d5 ^5 ?1 m5 U9 ~6 d; g5 ~( \
set current-light nobody ;; just for now, since there are no lights yet
# ]/ f; g8 V7 y/ R' ]9 [ set phase 0" M8 @2 w8 ?) q+ X- y7 S( `' S% F
set num-cars-stopped 0
4 f. h* `+ ~" o set grid-x-inc world-width / grid-size-x
5 ^9 g7 r2 Y! ^+ K# t% ~( w9 k0 m set grid-y-inc world-height / grid-size-y
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}( d- ~, }% O6 z+ q- N8 J0 H ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
- Q% F8 C; K; _# e7 F# n set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
5 L$ R8 G" ~: `% d;; and initialize the traffic lights to one setting
+ M+ |; p6 H( ~9 t2 o+ r& K6 Zto setup-patches B& u. U9 M1 i- _
;; initialize the patch-owned variables and color the patches to a base-color( _$ ]% w. i& B
ask patches
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set intersection? false
' o7 A/ [- i, E- t3 Z& t3 z set auto? false5 E7 D; I2 w+ R; b% u
set green-light-up? true1 J+ }( t h5 w4 Z8 |
set my-row -1
) H. {) I5 X8 T: g+ T set my-column -1
3 m5 c \% G# m) S set my-phase -1
7 S* D0 o/ P0 {' H% U: M set pcolor brown + 3
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. B1 }, ?8 ^$ T" X1 | ;; initialize the global variables that hold patch agentsets$ O8 R7 J! s# l2 P$ H
set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]! g |4 e+ H% V6 }, C4 H% p( |, c
set intersections roads with$ \+ L; y: @) ^# C/ ]& o" C' O
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and% T: `; U; n( A3 z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ {& z! i" f4 g1 v+ C% T7 `
- J$ ]6 g9 t' N. f ask roads [ set pcolor white ]
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end
6 k ^1 P* x8 i3 H* E1 h. `其中定义道路的句子,如下所示,是什么意思啊?, N7 f7 d" }) c4 @- x% P% _
set roads patches with. J- `5 `2 o4 i
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' B, [' r, `) i. m9 T" ` (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# b- P+ }' g4 \6 y. F- u3 @; Y& V" O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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