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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。
$ T6 ` H/ k9 M$ F4 p+ Hnetlogo自带的social science--traffic grid这一例子当中,- U: \# Z% t4 O8 b$ C" F
globals- A" i, R0 B8 z. g7 o6 f1 d/ q, E
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grid-x-inc ;; the amount of patches in between two roads in the x direction- s, V! `& }- q- D6 D
grid-y-inc ;; the amount of patches in between two roads in the y direction. c- N @) R2 b4 A
acceleration ;; the constant that controls how much a car speeds up or slows down by if; G, M* v$ Z9 H4 o6 D
;; it is to accelerate or decelerate
2 l- G4 N# r8 i) { phase ;; keeps track of the phase
% m+ u% q9 K! R+ @+ n num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
8 L* Q5 d" Q0 C( V current-light ;; the currently selected light! N5 k$ \7 U3 ]8 {# ]
5 a' @8 H3 G& K0 B% m& L/ r ;; patch agentsets+ F) w6 a, C+ A
intersections ;; agentset containing the patches that are intersections
0 ]3 `- r' G# `+ k6 D2 s `/ l+ Y roads ;; agentset containing the patches that are roads
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& m# U/ A3 e! l* uturtles-own
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# M- l( C5 k' V6 g! D. ` speed ;; the speed of the turtle
; E+ f/ N% u0 \, U0 o2 C( P up-car? ;; true if the turtle moves downwards and false if it moves to the right* V" q+ t4 F. `! q7 Q7 ?$ c
wait-time ;; the amount of time since the last time a turtle has moved6 x3 s8 T4 _" p
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( J+ p, M1 Z. s: Qpatches-own
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. x: Q, a7 s+ d7 _ intersection? ;; true if the patch is at the intersection of two roads) ~) Q6 h' y$ k( @
green-light-up? ;; true if the green light is above the intersection. otherwise, false.4 A: d, C$ L4 {; X" V+ v
;; false for a non-intersection patches.
% F L* |( v% ~ my-row ;; the row of the intersection counting from the upper left corner of the
; ] T C% t) X7 F ;; world. -1 for non-intersection patches.& _4 X$ ~% V8 o# u5 B: i
my-column ;; the column of the intersection counting from the upper left corner of the- n% A8 ~+ C- f. z1 Y
;; world. -1 for non-intersection patches.: V, L( j% F7 C# {/ p! ?
my-phase ;; the phase for the intersection. -1 for non-intersection patches.( \) ]: p l, N: z
auto? ;; whether or not this intersection will switch automatically.* u1 \5 F. B. R: O# _& w4 b
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;" I) P4 d2 ^6 A5 l' }. h
;; Setup Procedures ;;! s9 h+ N5 R$ l! Q% f4 g0 j
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;; Initialize the display by giving the global and patch variables initial values.
0 v1 ?! y$ _: E) N( J;; Create num-cars of turtles if there are enough road patches for one turtle to
0 p6 v7 Y* a( }2 t4 T- q;; be created per road patch. Set up the plots.) c" N S) t2 D$ E( H
to setup
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" d+ t% q: I, u8 c c% n setup-globals- V- f1 i1 T; |8 U% t; p
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;; First we ask the patches to draw themselves and set up a few variables6 u% ]( [1 W4 `, |7 B' z5 N
setup-patches
4 b( u9 _& o) R1 x, `3 s make-current one-of intersections) g8 ]7 u* c$ ]
label-current
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6 j7 a3 a L2 v5 R& @3 q4 P# X set-default-shape turtles "car": m2 X2 ^4 c' _+ y) Q, a' t! S
/ F1 F5 r! H; A) Q: w6 `* F if (num-cars > count roads)' x3 ]+ I: n1 [) ~/ J
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user-message (word "There are too many cars for the amount of "1 y U1 ^7 w! I: D
"road. Either increase the amount of roads "( V- ]' g+ J4 `! B0 u" B8 ^
"by increasing the GRID-SIZE-X or "
/ f2 B! w6 b- Y# ~- R, S "GRID-SIZE-Y sliders, or decrease the "
# z5 A9 b7 v0 E7 t. \ "number of cars by lowering the NUMBER slider.\n"
# A r. m) S" W/ p "The setup has stopped.")
' W/ K4 J0 i: V0 c! F! k5 J' k& Z stop n6 b4 p: X3 Z- A
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1 i, }4 z& H, h3 X6 \ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
$ \" A0 V" D3 `" i5 T crt num-cars
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& d" f. o3 {1 D/ B2 \1 P' L setup-cars
: P; J# f7 u+ y' w$ F set-car-color
2 Z" W: J! `5 @) [ record-data0 z" v" ~. v0 ^; f! h6 J9 k
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/ b8 f3 V5 x, N+ _1 U! Q' e P" Z ;; give the turtles an initial speed
( t- l) [3 b2 ^9 ?3 G+ H ask turtles [ set-car-speed ]; l1 t, ?; ]( r- f0 f, t
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reset-ticks R7 y3 [) x! T g4 i- I
end
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9 ? w; Z' M8 B; g# l( {; b2 i;; Initialize the global variables to appropriate values
% X8 R/ L1 u, g" d1 Z, P9 |to setup-globals
% k8 c* x( c- _/ o0 } set current-light nobody ;; just for now, since there are no lights yet
' z3 E" Z, a! A7 z. o set phase 0
' l, G8 Q% ?, h! O- U# l* x set num-cars-stopped 0' y( t0 ^+ _- ~; J
set grid-x-inc world-width / grid-size-x
+ G) P$ v' I; n, J set grid-y-inc world-height / grid-size-y% p" B: Q$ ^5 L9 V- Z3 t
* R# G+ C* E t1 t: C ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary- A6 ^ |: A8 q- {- t s @
set acceleration 0.099
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. O& Q. |, [& m* ]; w9 N1 Z8 Q. n;; Make the patches have appropriate colors, set up the roads and intersections agentsets,+ l: M1 w1 A" T$ |! i1 E
;; and initialize the traffic lights to one setting
5 M0 X7 ^, U6 bto setup-patches
$ A, K5 M. e0 T* R ;; initialize the patch-owned variables and color the patches to a base-color
0 v, F N3 @8 n+ M' ^: L ask patches5 U( ?/ `9 C" |2 F. ~2 r& X- Q
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set intersection? false0 {% ^( P3 M+ l
set auto? false7 T, m4 b5 ~( ~& {1 K/ o' a4 D1 t T
set green-light-up? true
- U& C" N* _! i' Q/ n set my-row -15 F0 d7 V, [. e7 U
set my-column -1# L5 I7 ?+ |3 a9 |: T( u% e* c! t+ P
set my-phase -1
v) b" ^/ e3 x8 I, q+ e# w set pcolor brown + 3/ G8 l& s1 U+ S# n# w! [ k: s" l
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;; initialize the global variables that hold patch agentsets
5 S7 S2 l/ l, w; {# b+ P set roads patches with
% s3 D$ S6 o+ C4 B" v [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
% k; f! ^% b" D (floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 M- F$ I9 R# M5 H; N3 k7 h* G
set intersections roads with
# s( m; _, u$ O ` [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
$ _; P& ~" b3 G; y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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, U2 F. j# ~0 X% { ask roads [ set pcolor white ]+ m2 C6 d5 t9 Y# A
setup-intersections# g7 ?( W. ]9 M/ v* R8 O
end& P6 y! t4 b* B* f
其中定义道路的句子,如下所示,是什么意思啊?* z9 Z5 g* U# ^
set roads patches with
8 W6 _0 c8 A8 p [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# Z/ R5 F5 ~) _1 D" w8 b5 G/ U (floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 u& y7 u2 d. v* G/ P8 N9 ?
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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