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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。+ o8 a) S$ H* }
netlogo自带的social science--traffic grid这一例子当中,
' ~2 M3 p; h% B! K9 X$ y& x& Nglobals
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1 E7 t( |4 `3 b/ _. P grid-x-inc ;; the amount of patches in between two roads in the x direction
. _( \9 z+ C2 D$ n grid-y-inc ;; the amount of patches in between two roads in the y direction- F* L! a( J2 Y) b
acceleration ;; the constant that controls how much a car speeds up or slows down by if- s% I' V% [5 q& ]7 W0 ~
;; it is to accelerate or decelerate
* m: a6 d2 U: f5 B phase ;; keeps track of the phase
7 ^1 k, y4 b/ Z num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure( u% r2 Z ^; m" Z" F! Q
current-light ;; the currently selected light* A3 I$ |6 S$ `& ^, j' m6 o8 N9 ~) P
4 s) l8 n+ i) L' a ;; patch agentsets
`/ K% e8 l* C intersections ;; agentset containing the patches that are intersections
9 ~% I& r7 j3 ?' o$ t; i2 P* \ c roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle
" t" Y, ?, U$ N" X' R! |' c9 V up-car? ;; true if the turtle moves downwards and false if it moves to the right7 G6 l/ l7 ^' M- E5 A3 \) g
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
* j& _, `3 i6 i m' [* T3 L, b1 S green-light-up? ;; true if the green light is above the intersection. otherwise, false.7 c A* z/ A1 x
;; false for a non-intersection patches.4 K! ^# w2 Z4 E, T" i
my-row ;; the row of the intersection counting from the upper left corner of the; t) f1 E" B/ m$ u1 q
;; world. -1 for non-intersection patches.' t X% u. S. N% U
my-column ;; the column of the intersection counting from the upper left corner of the0 m" ~& I& z+ G4 R
;; world. -1 for non-intersection patches.3 y2 `( l" H5 o/ Y! R6 O( c
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
' m4 Q' l) J% g+ y8 q" ^& x auto? ;; whether or not this intersection will switch automatically.
/ g7 z' P2 N) ~" Q( ~7 V- T ;; false for non-intersection patches.
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- E' S: A* a6 y$ ]' M2 n;;;;;;;;;;;;;;;;;;;;;;
( k6 r8 `6 g% X* _;; Setup Procedures ;;7 a* i* W. S" z7 \+ I, R
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4 p/ }: w' @# y8 K4 _' l6 m1 c;; Initialize the display by giving the global and patch variables initial values.0 m/ \, Z+ x: o9 Q
;; Create num-cars of turtles if there are enough road patches for one turtle to$ c/ r4 i" t3 u( h# i! |
;; be created per road patch. Set up the plots.
. I' M# E; B2 G$ Eto setup
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7 q5 s1 q. l( U) N setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
. e! p2 N/ h8 u9 ` setup-patches
' x3 b# u" T' \! P2 Q- @ make-current one-of intersections
/ p/ b1 y% G- o+ @ label-current
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7 q: T. g0 G3 v9 Q" J3 | set-default-shape turtles "car"$ B( N% ^% E6 L2 G6 L
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if (num-cars > count roads)" M2 w9 F5 l- C! z
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user-message (word "There are too many cars for the amount of "' I- H; S( V( b/ [+ p+ i+ \
"road. Either increase the amount of roads "
; f: j4 o$ ~ X- f- Y "by increasing the GRID-SIZE-X or "1 ^9 X% X- d, m7 G# W, v; b
"GRID-SIZE-Y sliders, or decrease the "
! C# Q$ ?# ^" \9 G! N( J "number of cars by lowering the NUMBER slider.\n"
7 r- |- ]0 R& \0 q7 i "The setup has stopped.")
7 |! H' N- @2 l6 ? stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
6 @0 v0 o8 w5 D( m/ }8 w2 V. C$ i crt num-cars' J+ |# W/ X& ~
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setup-cars
( ?3 B' j4 W) ?0 \+ C set-car-color* H) _# d9 N2 n0 I' v! L
record-data
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;; give the turtles an initial speed
+ ?$ @6 z3 _+ h$ B ask turtles [ set-car-speed ]
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" I2 ?. m/ X* L reset-ticks {3 c: b( u, i3 b4 x+ F# p
end" c$ Y! |1 u, e! f8 d* p& D
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;; Initialize the global variables to appropriate values, w! H4 S: I! Q$ L7 s1 p1 w) L0 r: S
to setup-globals
! ]* m2 F) R; K6 c A$ a6 r set current-light nobody ;; just for now, since there are no lights yet: h: m$ p; C! _' ]
set phase 0
$ ~* D1 P0 _7 Z3 g1 Z set num-cars-stopped 0
- j4 {! ]$ A9 s7 n set grid-x-inc world-width / grid-size-x* Z0 Z( b0 d3 m: [, ]$ j8 d0 B. o
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: T. ]% l1 x7 Z2 z i
set acceleration 0.0994 y9 t% H7 e, F
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
7 C" n1 u4 E3 C% Q8 V/ r9 o2 v/ l;; and initialize the traffic lights to one setting2 v. u* u( ?* u, t
to setup-patches- H9 D% N. K, s/ j$ L; S2 H, |
;; initialize the patch-owned variables and color the patches to a base-color
$ T$ F4 H9 x3 W# |! c: I: I ask patches
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set intersection? false) e0 K0 J9 I! a- h m" [; n
set auto? false
* B4 X% u+ y. L) o set green-light-up? true1 I* {6 V% b8 k6 E$ Y
set my-row -1( r$ s! J9 Q5 h+ n9 e5 O! L% ]
set my-column -1! G" K" o- D# B V5 ?+ I8 b
set my-phase -1
' ]' l1 j f5 V$ W/ p set pcolor brown + 3/ w) @+ [, T V/ P' ~
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;; initialize the global variables that hold patch agentsets
4 }# j$ Q' ]7 h0 Q/ n( l" M set roads patches with
b) z- {+ A$ f* [1 Q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or7 m. G- Q q! R
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ o* O% z L4 e$ ]) ^, G ]
set intersections roads with
% z! w( m, s( s, r [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
* G1 ~0 N& p8 D9 t/ v: w (floor((pycor + max-pycor) mod grid-y-inc) = 0)] ]- L7 Q$ a9 U; B2 z: o. a$ w
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ask roads [ set pcolor white ]
( b' D0 ^ X* y" B 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?/ N( q$ M7 D( ~4 B2 b/ _$ z
set roads patches with
3 v3 u) F1 r3 N5 i: G. ]4 [ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
$ R% T8 B2 h. l (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, t3 P3 L. Q% M! k1 k" O4 G9 E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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