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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。/ ~" C; \) F: n4 J u. g3 N
netlogo自带的social science--traffic grid这一例子当中,
$ L9 v( A; p. F+ R5 v, dglobals0 x0 m3 D1 h. O' k. N; K) |
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grid-x-inc ;; the amount of patches in between two roads in the x direction: G2 O+ O% N+ d! Q6 k0 w
grid-y-inc ;; the amount of patches in between two roads in the y direction
) V) @6 P, s' r acceleration ;; the constant that controls how much a car speeds up or slows down by if
3 Y/ o; f* h+ l( b: A( B ;; it is to accelerate or decelerate
; @: I( J* ~3 k1 ?- D& q8 r0 q/ ^ phase ;; keeps track of the phase$ }5 l( j* O( M
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure1 [+ F7 t; d8 K- U/ b
current-light ;; the currently selected light
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9 ^' \. i4 M( g% c ;; patch agentsets
2 h7 d, b3 n9 {; ~: P( s intersections ;; agentset containing the patches that are intersections
+ ]1 I1 c" X3 s3 \1 s roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle! ]: }1 o* w, S% u/ P4 |% _$ M, _- e
up-car? ;; true if the turtle moves downwards and false if it moves to the right
7 k1 g2 R% k& }- l! K3 O( M7 i wait-time ;; the amount of time since the last time a turtle has moved
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patches-own1 D; k, g& L/ t0 U5 f
[
9 l9 Q: Y( x% M intersection? ;; true if the patch is at the intersection of two roads
! n: f6 _% Q! y) _' t: J green-light-up? ;; true if the green light is above the intersection. otherwise, false.8 p- U9 `+ g% N, B; j8 p/ I7 P
;; false for a non-intersection patches.' B& e+ G; s2 j% O5 x
my-row ;; the row of the intersection counting from the upper left corner of the
3 Q" b% l4 d/ [7 x- h ;; world. -1 for non-intersection patches.: w9 A7 f4 h; k* ^+ X
my-column ;; the column of the intersection counting from the upper left corner of the
( @- B8 t2 A7 d& v P. u ;; world. -1 for non-intersection patches.
, g4 {- M, y8 c. D my-phase ;; the phase for the intersection. -1 for non-intersection patches.
3 @' d8 T ]0 ^- p- V auto? ;; whether or not this intersection will switch automatically.
1 H* }7 p9 I' @/ Z ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
3 z- t; E4 l( |* @2 ]9 A- c;; Setup Procedures ;;9 E' B3 D' Y: i9 |% {5 A5 c q
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;; Initialize the display by giving the global and patch variables initial values.
{% h3 M4 L8 V# k$ F5 s;; Create num-cars of turtles if there are enough road patches for one turtle to1 z. c+ Q* Q, P: m* ?
;; be created per road patch. Set up the plots.
1 O5 c+ n& h( Q- h" eto setup
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$ ?+ c4 c, K% n: k6 I9 h setup-globals
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;; First we ask the patches to draw themselves and set up a few variables |" w* `$ b7 ~& b: ^5 k' }$ S
setup-patches2 y; \5 p) J4 F2 {+ q( u
make-current one-of intersections
' W! v* [. m7 p6 B# Q; [8 [5 O label-current
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set-default-shape turtles "car"7 w& u' U% `, \0 b
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if (num-cars > count roads). ]3 h6 D- ~* F
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user-message (word "There are too many cars for the amount of "+ T9 ]5 u8 h. X/ \. j% ?. G
"road. Either increase the amount of roads "
, L; |- \- C' {' _& A% A& _* |. S/ V "by increasing the GRID-SIZE-X or "! n$ ?$ X! f, Y- f( h, \
"GRID-SIZE-Y sliders, or decrease the "
6 I2 G/ `2 A- P "number of cars by lowering the NUMBER slider.\n"; \* n/ U( a, s A
"The setup has stopped.")6 `. u' m5 C. g1 a# e3 Y: y
stop1 l1 D; [2 v6 O9 E e6 C
]
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
) r4 e. Q1 E' d5 s/ R& E: r; u crt num-cars
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9 g9 b1 d4 k- ]6 V/ A/ E# s setup-cars' c& Y# h5 C- _) W, v
set-car-color5 z' ~% a5 z* `2 f% H
record-data" a6 q# t" m$ E. D, U8 J! q: [) i
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;; give the turtles an initial speed( \6 E+ b: W3 x& J+ C" y+ A) ?: s% h
ask turtles [ set-car-speed ]
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, |/ I# i6 m8 Y* } reset-ticks# v# d4 H0 O' Y P7 }4 t
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;; Initialize the global variables to appropriate values
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. N9 N# j+ A" J" Y: A5 k set current-light nobody ;; just for now, since there are no lights yet
" b. p+ y# S7 A1 r; x8 l set phase 0
( N1 O2 [: R* ? set num-cars-stopped 0
8 r/ D& N5 ]7 J& C8 P, ?) H set grid-x-inc world-width / grid-size-x: _$ t1 K0 ]- h3 }' |5 R6 D
set grid-y-inc world-height / grid-size-y) G" G/ _8 k# l0 ]0 Y6 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
+ `2 n: D. m; Q# p- p set acceleration 0.0996 y5 e, m$ O6 h/ S3 ?% {4 f
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,% `7 ]( |6 F. f: _5 G
;; and initialize the traffic lights to one setting
) M' Z8 W7 t5 s* W4 Fto setup-patches- C+ _' \" ]; v) t3 l
;; initialize the patch-owned variables and color the patches to a base-color4 H) Q# g4 X2 T; d6 K) U
ask patches
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7 M; @- x% k* b3 H# a" r; j6 X set intersection? false
- J+ Y, z4 v7 u/ H" }& q set auto? false
/ D& b6 ~8 w0 K! l5 g2 n3 W; E B8 K set green-light-up? true
0 v4 R1 f; i) A* g. |; M$ g set my-row -1
7 H2 D& h: n! g' ^+ {! | set my-column -1
) B# A# q) {' R5 O set my-phase -1
! h8 C+ N& ]+ ^8 r8 F S set pcolor brown + 3- a& Y9 Y3 w. E0 G$ s+ A
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3 p5 n5 l: ?# v: q( C; }! T8 [ ;; initialize the global variables that hold patch agentsets
; n8 B$ T$ c4 P set roads patches with
7 T6 ~6 {: f' A [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; Q; W2 L$ P# w (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 a$ V* |# E* T' \! ~ set intersections roads with
5 P, B9 ?" J, r* v* e [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and; D6 j1 L1 ^7 z6 q$ l$ I: k
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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* _: t& O' z$ E ask roads [ set pcolor white ]) r" Z" ]+ D$ Z J$ i* q
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?
W) |/ j8 ?: J7 _! e# L! i set roads patches with
* W8 W, I* ^) s1 a0 s4 A [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
) ~& q' W6 n9 B- x/ } (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: {/ |5 y6 H9 ]$ `$ {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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