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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。0 G. H* t2 U3 B' Z7 D) b, F
netlogo自带的social science--traffic grid这一例子当中,
$ l' i0 ]5 C8 wglobals
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; K+ G7 z" x2 Q) a grid-x-inc ;; the amount of patches in between two roads in the x direction# ^; n/ u4 a C5 m3 t0 m
grid-y-inc ;; the amount of patches in between two roads in the y direction
; a9 @ y) b, P/ D acceleration ;; the constant that controls how much a car speeds up or slows down by if
3 e7 ^+ W8 z6 Q' c; e: p ;; it is to accelerate or decelerate
2 D4 }7 y% H$ a( N phase ;; keeps track of the phase
6 H+ t+ R% C; i% s; v num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
. g0 U! o1 l$ m* L current-light ;; the currently selected light
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. a. |" Z" T2 C' A ;; patch agentsets
3 |. c' O% @ K+ Z& a+ W5 ]8 u1 k6 U intersections ;; agentset containing the patches that are intersections1 L( ?. n4 k/ B% N" h* W
roads ;; agentset containing the patches that are roads
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turtles-own
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8 x1 `$ e" x8 r0 z: L speed ;; the speed of the turtle
/ P( p5 r* w% ]- F, O up-car? ;; true if the turtle moves downwards and false if it moves to the right
* A z$ J2 u t wait-time ;; the amount of time since the last time a turtle has moved
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patches-own+ b+ \! f) R' R6 \0 s
[
! v9 [& l% { H! ]/ u+ l( V intersection? ;; true if the patch is at the intersection of two roads
/ r7 t# d& h3 V$ g green-light-up? ;; true if the green light is above the intersection. otherwise, false.
+ p N! J" \, t ;; false for a non-intersection patches.$ h$ t# t- u$ c( y
my-row ;; the row of the intersection counting from the upper left corner of the
% S2 D1 E/ k, Z/ `5 n5 ~9 j ;; world. -1 for non-intersection patches.. X$ k% ]* b3 }
my-column ;; the column of the intersection counting from the upper left corner of the+ O1 i; G/ w4 n" B+ y3 M, X* L
;; world. -1 for non-intersection patches.9 Y& y1 s: o$ E7 z4 H2 y
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
# t, Z2 i& S' W' z: o( l7 ^* e auto? ;; whether or not this intersection will switch automatically.& G" {7 F, o" f9 Y" Z6 W% v
;; false for non-intersection patches.# l. m8 `( |+ G/ F ?: z8 ~
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- W. T* q7 |8 M8 ? f2 e2 }7 _;;;;;;;;;;;;;;;;;;;;;;. u* [7 ]- p8 L0 X
;; Setup Procedures ;;
7 V3 n. Q. B+ [* _& _;;;;;;;;;;;;;;;;;;;;;;
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- e& o% ]4 O j2 Y3 t;; Initialize the display by giving the global and patch variables initial values.
8 J2 _& v$ `. G% i% Q9 O b6 d: `;; Create num-cars of turtles if there are enough road patches for one turtle to
7 v% H; j3 M# [9 ^;; be created per road patch. Set up the plots.3 V% a6 r) v- b3 N/ C8 ?
to setup/ z' }2 }) a. P5 M( y* G% k3 y p* Q% R
ca
7 G% F& `$ [, A/ }- g setup-globals, z6 _0 l' h& @9 W
- d2 S( s$ m4 Y; ]: w& b ;; First we ask the patches to draw themselves and set up a few variables
/ {3 p! q3 j( L6 X setup-patches" V3 H; ]0 {! u
make-current one-of intersections
; Y! m4 `3 j$ q# w0 Q- E, @' H/ u label-current
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set-default-shape turtles "car"/ z6 }4 U2 n$ s, ~# t
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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 "
/ }- @1 L5 Z9 s "road. Either increase the amount of roads "
) Y, l n5 o* d1 d "by increasing the GRID-SIZE-X or "& v j* A3 l9 D! {& Z5 i
"GRID-SIZE-Y sliders, or decrease the "
) @" ~( f9 {2 z1 C% H+ s6 t "number of cars by lowering the NUMBER slider.\n"3 R3 k2 f1 u4 s
"The setup has stopped.")
9 P' J* x E Q4 o }) y+ h) }* P5 ` stop
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2 W \9 b$ }6 ~/ S$ k9 v ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color% l! e, l' j8 @7 M1 d4 o+ Y
crt num-cars, ]# K" b S4 {6 [, D0 J
[
R7 B. }7 s( h setup-cars$ ?- Y# `. P- m' _4 ]; ]& X
set-car-color) g+ Q( p& x/ j o! A$ s
record-data" Q6 x3 i! g+ |. \0 ]
]
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4 A' \/ _* {# R! b# I6 k ;; give the turtles an initial speed
& i7 r: W0 P9 n ask turtles [ set-car-speed ]
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reset-ticks8 w5 O$ q* | E& }. `2 u
end
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. p/ y. F. _* @& \; K! z;; Initialize the global variables to appropriate values
$ u5 Z/ A: ~+ s5 C4 vto setup-globals
4 _' Y, ^8 }9 M9 { set current-light nobody ;; just for now, since there are no lights yet4 Q/ v) O$ s. i7 d) h- O5 F
set phase 01 o% j- Q; O. M4 |! z) f* s' N
set num-cars-stopped 0/ t& ?4 P7 F9 s& L N
set grid-x-inc world-width / grid-size-x
. g, T6 v2 g5 ?' R F 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 boundary4 V7 R' i, J L8 M
set acceleration 0.099' \5 r' f+ f7 Y, ^7 l
end6 e) l+ k; f( c% h
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,7 w% }: F' ~& ]+ l+ f5 z4 T2 ~
;; and initialize the traffic lights to one setting
. N3 N5 Z8 l9 w1 S/ ?* i, Fto setup-patches
' k5 g+ o7 U1 o ;; initialize the patch-owned variables and color the patches to a base-color
* f( q3 q, R3 S( P( Z% c2 [ ask patches
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5 n- W3 Q! A- x0 K; ]4 P+ \# l% R set intersection? false) D# r K( G8 C5 {5 W
set auto? false! _( n- p7 N, f
set green-light-up? true. [ ^) w w8 d7 R) P5 D f, ]# b* v
set my-row -1
! D- F' _' I2 e3 e! j7 E set my-column -10 C4 A1 T; g% i$ M6 W( [/ V
set my-phase -1& [6 n4 D7 S7 _
set pcolor brown + 3+ k9 y( L4 o' h
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) g& H6 G" E7 V* }2 e, W- D ;; initialize the global variables that hold patch agentsets
9 ]1 k! ~2 l4 x& h% \7 z8 O set roads patches with& o z% |0 H; V
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* H" C/ j; ?" X* K' Y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ A. T* a/ }2 o* H: _5 a* u set intersections roads with
+ H" }5 E9 V) w8 h4 X [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
' [; d0 ^1 A1 i (floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ g; f" y4 `! g' |4 f
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ask roads [ set pcolor white ]! m* i6 s6 W+ l5 I- k9 m
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?2 c" r1 B. s- `5 t: b
set roads patches with
( T( g* ?4 ]' o+ D7 G( \ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or# s# ]8 P# e8 C6 E# v7 L N5 N: S' H
(floor((pycor + max-pycor) mod grid-y-inc) = 0)], _1 A5 P# q9 A- l4 J! q9 l2 s2 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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