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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。/ r+ o% V, k- ^8 k/ k1 [9 F
netlogo自带的social science--traffic grid这一例子当中,8 w! ?( I; c. ]* E3 t. l
globals
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4 ?1 [, Y% {1 g* s7 K grid-x-inc ;; the amount of patches in between two roads in the x direction
* U) n# j! Y. l" t4 M( e/ k- o5 ? grid-y-inc ;; the amount of patches in between two roads in the y direction
4 G- W: _& P1 Y) O" v acceleration ;; the constant that controls how much a car speeds up or slows down by if9 i, t- @* u, {) E# x+ D
;; it is to accelerate or decelerate8 @/ y2 J' ?$ B- z1 g
phase ;; keeps track of the phase
7 x: m( I0 A# i! T$ Y; Y num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure/ p/ M& \. l: P+ a0 t4 l/ `
current-light ;; the currently selected light
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2 V) l" ?! ~: F# l5 } ;; patch agentsets
8 j6 ?- Q- s }7 R( w+ H intersections ;; agentset containing the patches that are intersections
% M; g9 L2 z8 W2 S0 W! M roads ;; agentset containing the patches that are roads( H, W1 k7 ~$ {" @! d8 s1 Q! {
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3 T: e9 {- h( `turtles-own
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* Y; g5 c5 P( ~7 C0 n; v' u: Z speed ;; the speed of the turtle8 |! {# \% ?; ]
up-car? ;; true if the turtle moves downwards and false if it moves to the right1 d h+ Y" f+ L! {- S
wait-time ;; the amount of time since the last time a turtle has moved2 Z$ i3 @( W& T+ d7 q
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patches-own. a k& ] q5 A; n/ l# I
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intersection? ;; true if the patch is at the intersection of two roads
& h2 Q# r h5 Y0 M- F- f( D green-light-up? ;; true if the green light is above the intersection. otherwise, false.9 |$ C! x/ L" u1 E/ l, o* I6 x
;; false for a non-intersection patches.8 L* v7 X) l! F _- _1 j* @* t& W4 e
my-row ;; the row of the intersection counting from the upper left corner of the
3 Y9 m9 H$ P$ a+ j ;; world. -1 for non-intersection patches./ j3 b* ^/ c* q( M0 t
my-column ;; the column of the intersection counting from the upper left corner of the2 h6 V m( q4 y
;; world. -1 for non-intersection patches.* u" t2 S% p* R2 N! c1 Y
my-phase ;; the phase for the intersection. -1 for non-intersection patches.& {- W, J8 H; `6 b2 w9 l- x
auto? ;; whether or not this intersection will switch automatically.6 A$ Z( [ U* U& T; f
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
* @9 G- b0 q) m: J% r1 ~6 Q' n+ I;; Setup Procedures ;;! m" f l: z0 S6 ?7 b1 l
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# w8 @9 H0 v2 |/ l& i7 _;; Initialize the display by giving the global and patch variables initial values.
- d. d" u- C+ @" _, m# S5 x! ^;; Create num-cars of turtles if there are enough road patches for one turtle to( q$ \' [8 v- }( J$ D3 ] a
;; be created per road patch. Set up the plots.
" \: Y; E2 [1 v5 Pto setup2 o) G. M4 Q% F/ T( d, H
ca
$ A9 l9 n* h$ e/ A% u setup-globals
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9 U# p' _- j) C0 g6 H( | ;; First we ask the patches to draw themselves and set up a few variables4 C4 L* A1 R0 j$ A' X3 L9 |
setup-patches' {/ M! ^; O* K0 m u9 L+ g9 l
make-current one-of intersections
+ E. |% z* r4 z! o0 k8 m B label-current
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3 Q2 [/ Z+ Q: ` set-default-shape turtles "car"8 j# ~1 b O8 k& N
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if (num-cars > count roads)% P2 v( N, Q* O' p
[
( u. o- w1 k; ^2 d% h# ?8 b user-message (word "There are too many cars for the amount of "8 A& }9 \. c' s1 b+ G/ m
"road. Either increase the amount of roads ". ?/ P- i7 m* ]/ W: }# i* m# @
"by increasing the GRID-SIZE-X or "
& ~4 k% M/ {$ ?& @' Q1 u8 | "GRID-SIZE-Y sliders, or decrease the "
' K$ |0 @$ m6 y" `" c "number of cars by lowering the NUMBER slider.\n"& E3 W/ l& c+ W+ |0 w3 B- x1 w7 Y- D
"The setup has stopped."). s2 D/ W* W' n* ]. j% r9 y
stop. n4 z+ d4 Q3 W" `) p. w: f! ?
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
: @8 [* U: y/ h/ W crt num-cars
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& X2 |. N0 y# w setup-cars
6 C6 o* v8 Z3 P5 ^7 a) V: ?5 W set-car-color
( m9 L; j+ u" l" ?5 R" d record-data! c: s* ^" O) Q) U
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;; give the turtles an initial speed
) v4 ~- j2 k- e1 s# S+ f ask turtles [ set-car-speed ]
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reset-ticks* q- @& c6 A$ m* B7 @% X
end0 o4 {8 }3 _1 y$ P' \& X( t
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;; Initialize the global variables to appropriate values
3 \: X3 _7 E* H' K! B2 zto setup-globals
& g+ s0 H+ L1 a set current-light nobody ;; just for now, since there are no lights yet# m- ]0 {: [. I* W5 Z' n
set phase 0
( ^+ y1 Z: |( x& o set num-cars-stopped 0
( s1 h5 E5 L$ s& m3 s2 ] set grid-x-inc world-width / grid-size-x, u' f/ y y) ^9 c' N: V
set grid-y-inc world-height / grid-size-y- A3 o) f q0 O
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
0 r; [2 @4 V8 W! u. \ set acceleration 0.099" q4 Y# H, r) N, {" _' I" M# Y
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
4 G4 T7 q7 Q0 Z1 k;; and initialize the traffic lights to one setting) V1 J. I$ I2 I- G* v
to setup-patches
3 ?% H9 W; H" T+ r* L ;; initialize the patch-owned variables and color the patches to a base-color
2 s+ `2 P. b5 X* ]6 M2 B ask patches
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set intersection? false& P) d0 f: n! p" i C! ^
set auto? false6 Z4 K/ S5 z) m" M: |! B- U
set green-light-up? true
" K- @# o. |9 B set my-row -1 |/ z5 Q' B9 C4 `! A# L' v
set my-column -19 z9 Y- K G8 @! J
set my-phase -19 X. T. i$ c4 l
set pcolor brown + 3 L+ X( o8 q7 J3 s0 b
]
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3 ^& L, Z" H1 Y* K1 m ;; initialize the global variables that hold patch agentsets
/ M z. o" t6 @5 q- F8 _ set roads patches with
& J* i, U+ e2 m3 I [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
) t1 K; D& K/ M$ n9 p. m (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ L8 {: x! S" Z/ F8 ^7 d1 ] set intersections roads with
; W# b0 l' u/ y/ R1 g7 W, [ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
( y: m2 G8 W' R2 d (floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 h" R6 ? O) M1 A/ M' C3 F
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ask roads [ set pcolor white ]
. j5 [' m2 G* L3 y) L5 O setup-intersections
7 Z9 w+ M ~6 k: Y$ P9 yend; u- Q$ A |, @: x; T+ {2 }
其中定义道路的句子,如下所示,是什么意思啊?! }8 O. O3 d5 h* o# ?
set roads patches with6 l' \9 w7 B- h4 a$ X6 D1 Q' E% @
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) Y# J4 n t/ {
(floor((pycor + max-pycor) mod grid-y-inc) = 0)], D' n; K. I' N
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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