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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。4 X. R* ?( O$ [" k% n
netlogo自带的social science--traffic grid这一例子当中,
0 i( F3 ]4 z1 O4 x* eglobals
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' S: D# Y* f6 u grid-x-inc ;; the amount of patches in between two roads in the x direction
; H9 X1 |% y0 L grid-y-inc ;; the amount of patches in between two roads in the y direction
4 r8 X. Z6 _' c acceleration ;; the constant that controls how much a car speeds up or slows down by if* c+ U% Z5 j- x9 @5 ~9 f
;; it is to accelerate or decelerate6 }. F6 U8 \$ N6 o: a. ~6 S
phase ;; keeps track of the phase; i/ [/ J9 t. H0 K0 l: P, G
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure8 v, |: [5 b/ u0 e0 l* T: D& q
current-light ;; the currently selected light
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3 O" N1 }' d* J ;; patch agentsets+ I6 a0 Y9 V6 ~5 i3 p! }
intersections ;; agentset containing the patches that are intersections
7 Q g% Y8 x4 W- ] roads ;; agentset containing the patches that are roads: n" d$ S6 F8 \/ N+ j7 p
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turtles-own
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/ H: @/ f# R9 D speed ;; the speed of the turtle
# V4 w0 {8 B" h5 {/ p1 e up-car? ;; true if the turtle moves downwards and false if it moves to the right
4 j1 M7 H, I, d* ^7 \ wait-time ;; the amount of time since the last time a turtle has moved
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patches-own, E6 S! |/ s8 o3 C
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intersection? ;; true if the patch is at the intersection of two roads
) `* y, E& ^- T, w6 v% i8 W green-light-up? ;; true if the green light is above the intersection. otherwise, false.8 v" D9 [8 a; C7 ?$ J! n
;; false for a non-intersection patches.
9 X4 t3 d. R: p, F- W8 ?( N7 ? my-row ;; the row of the intersection counting from the upper left corner of the- j* y9 x: K4 w6 \2 c7 D
;; world. -1 for non-intersection patches.
3 \6 J7 M+ U3 d my-column ;; the column of the intersection counting from the upper left corner of the
2 |% A; y9 C6 O! ?9 v1 c7 N ;; world. -1 for non-intersection patches.# _( v% t$ i; \% U) `. j' f; d# m' ^( F7 d
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
% y& Y8 m- I4 d auto? ;; whether or not this intersection will switch automatically.
4 n& [7 _8 r) T/ A E ;; false for non-intersection patches. l4 N8 h- g9 ]0 I2 C
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;;;;;;;;;;;;;;;;;;;;;;( H+ V I g# Q' l5 r" f& H
;; Setup Procedures ;;$ R2 v# a, L" B
;;;;;;;;;;;;;;;;;;;;;;3 i, `% g' U$ `/ \ y7 b
& O/ k4 c& ~& b3 \;; Initialize the display by giving the global and patch variables initial values.
+ n* q0 s: n! u0 b% w;; Create num-cars of turtles if there are enough road patches for one turtle to
+ c# s3 o# a w1 v) E6 B;; be created per road patch. Set up the plots., _& g' g( I# ~% Y+ a
to setup6 o+ E& s- M5 o k+ L) b
ca
; X' w1 j( a: x l4 [3 r; U' y setup-globals0 j1 H' F! U. K: g2 F w
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;; First we ask the patches to draw themselves and set up a few variables
9 Z/ B$ r! ]: v+ L0 j4 a4 H setup-patches- W9 R8 i7 G" w9 U; O
make-current one-of intersections
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4 ] R) b' U6 J! N set-default-shape turtles "car"% v C' } I5 g+ w D. ~
, r. g. a/ u' v p* U" M7 P if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "3 @. J2 e7 e+ \5 B6 Z n3 R
"road. Either increase the amount of roads "" X L& y/ @0 `7 @
"by increasing the GRID-SIZE-X or "; |5 K+ ?! ^& A- g! U# ]4 w/ u
"GRID-SIZE-Y sliders, or decrease the "
( f; A) f) C; v. I "number of cars by lowering the NUMBER slider.\n"
2 a# ?! n' R) K& K5 W6 f; T6 F "The setup has stopped.")
5 A" b) k5 N/ [& ?) N stop* }; V/ f7 @! o) r
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
0 _1 q" N0 B" o4 \/ k crt num-cars7 L5 F9 i: {) F. X: v7 U( n
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setup-cars
0 t1 T7 l0 K' ~- C, d5 V' G2 C# } set-car-color/ m% @, o3 J3 Z, S3 n7 e
record-data
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; }- O4 O/ L2 j) v* L( Y8 M ;; give the turtles an initial speed
3 n4 Q0 U8 ^6 S ask turtles [ set-car-speed ]2 h' y' `1 g3 L/ N; h
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reset-ticks5 x& l3 Q: e) B$ r
end
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9 x8 C% Y" E' };; Initialize the global variables to appropriate values: h% b) b* p4 z! H' \2 I+ q& F/ l& u, ^
to setup-globals9 }. f% \# l, u
set current-light nobody ;; just for now, since there are no lights yet
) e. H+ h. E$ v) y. g set phase 0, w' I( ?2 h* G: s$ r8 n/ a! t0 O
set num-cars-stopped 0, {$ k* F# R+ f0 ], g$ [# m
set grid-x-inc world-width / grid-size-x/ }( L' R1 s0 ?
set grid-y-inc world-height / grid-size-y4 K+ k- `4 G% s4 w5 T
/ |9 p! }" `: o/ ] ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
- N B, u& j* ~1 s# u. c" D set acceleration 0.099$ R" Y* w$ ?. `( n3 q0 h* r& G
end, g! J$ ]% ?3 p% y& H, V* i
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,: N. e7 k& W- W- f, S1 Y; m
;; and initialize the traffic lights to one setting
+ A2 ~9 U: i% U' Lto setup-patches
- H- u9 |1 x- Y2 x) M5 d ;; initialize the patch-owned variables and color the patches to a base-color8 I% \# n1 c6 x, I) v/ r3 ~' f8 P
ask patches' M. I' |) C5 u4 |4 S8 i
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( k' n O7 F% X5 \. g: C1 z; W: F' H set intersection? false' L. _9 @3 K F
set auto? false5 h5 b( L* o# r* b" R; z* e: z/ h$ J. I
set green-light-up? true
9 A9 F1 [. Z( [/ b5 J. U; @ set my-row -1
& M0 [1 X* Z* s) f5 J set my-column -19 I# d, b5 q; R. O: C! M# F
set my-phase -1
9 v+ Y; L( I& S6 F9 W set pcolor brown + 34 R: V+ }: C$ o( G
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# H- j7 `" T9 \) G ;; initialize the global variables that hold patch agentsets+ o" p9 S4 A9 e0 P7 t; i
set roads patches with
" X& R7 l6 r2 l4 v2 ` [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
4 V- @6 \& R( i; v U5 W4 { (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 l6 Z3 x! [" f0 Q set intersections roads with
0 ], K9 v8 T' | [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
q9 c5 j+ e" r (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; j# X1 G3 M5 P* S3 B! E
# F2 ~. N# }# a4 M/ }9 Y5 ] ask roads [ set pcolor white ]
$ B' g( z2 n3 s+ R/ t setup-intersections: F" ]6 H. e( O" l! A
end6 n1 v/ ^7 K' Q2 h- ~& R5 c
其中定义道路的句子,如下所示,是什么意思啊?
- H) P1 E, _. B+ G; b set roads patches with
9 v# I2 n/ g7 y' V4 f1 Q- { [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 z. Z j) g; g# {# z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]' c2 _ z6 B5 {. P. e% W0 c+ a
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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