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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。
3 O9 j" m6 H1 Znetlogo自带的social science--traffic grid这一例子当中,3 m, Z' Z' M9 Z' h2 ]9 T8 h
globals
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" }3 t! n1 X( b/ Q. F grid-x-inc ;; the amount of patches in between two roads in the x direction) G8 ^9 W6 |' E" X2 J! T1 d/ B+ q7 m
grid-y-inc ;; the amount of patches in between two roads in the y direction
- y* N) ~. e% z. }0 j7 k/ y acceleration ;; the constant that controls how much a car speeds up or slows down by if. I; u) {- H0 J& C# @
;; it is to accelerate or decelerate# X2 ~6 n/ b6 N. v( ~6 m
phase ;; keeps track of the phase
% q3 ^' A. l, N0 O num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
4 ^. q& l; q \ current-light ;; the currently selected light
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7 U9 [" V$ h8 B) t ;; patch agentsets. \$ [2 A" i4 {! S! h' V' U9 v
intersections ;; agentset containing the patches that are intersections" T8 \5 h( C% S3 p/ Y
roads ;; agentset containing the patches that are roads% P/ s5 N/ L, J
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turtles-own
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speed ;; the speed of the turtle( r6 x; @, f% ]. R, a
up-car? ;; true if the turtle moves downwards and false if it moves to the right
! ?4 d1 A, J+ a0 L e& ~ wait-time ;; the amount of time since the last time a turtle has moved9 ~$ ~. U4 h, U
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) a1 ^% e: s; w: ?patches-own
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intersection? ;; true if the patch is at the intersection of two roads' t; M- Q) i5 F6 r U" t4 ?
green-light-up? ;; true if the green light is above the intersection. otherwise, false.) N9 q2 a/ X1 \/ k
;; false for a non-intersection patches.( [6 Y4 @7 t' O) j. ^
my-row ;; the row of the intersection counting from the upper left corner of the. L4 ~! o* |9 P% z& B0 a* Y6 q
;; world. -1 for non-intersection patches.$ w7 P7 P. H7 Z) J
my-column ;; the column of the intersection counting from the upper left corner of the
6 |9 L1 G# v3 O* g ;; world. -1 for non-intersection patches.! r3 J! [) _" X1 c& n$ E4 c8 e9 F$ G
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
* e" y3 a' h- P# C auto? ;; whether or not this intersection will switch automatically.
9 N; n' k3 M! C# U" K6 X" e! Z" M ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
f8 w6 e1 X( f/ p/ D;; Setup Procedures ;;
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. O* k7 J: J1 _/ s1 r! L;; Initialize the display by giving the global and patch variables initial values.
2 T* f6 D8 [" W% o. E;; Create num-cars of turtles if there are enough road patches for one turtle to
7 o( t7 z- _, z7 `;; be created per road patch. Set up the plots.
- e$ j# b X& N4 K/ n. N) T fto setup9 I. `$ ]' j: e+ n1 c& \0 p
ca
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4 a* y" E j0 m1 N; w ;; First we ask the patches to draw themselves and set up a few variables
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make-current one-of intersections; M r! e, T" e7 k( a: d
label-current3 s: _+ O" p8 ?" s5 ?
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set-default-shape turtles "car"
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if (num-cars > count roads)
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$ G0 R+ {* s3 a8 O6 b user-message (word "There are too many cars for the amount of "6 y! M& m" d- h7 B3 B
"road. Either increase the amount of roads "
' X, z; ~0 ]4 t" l "by increasing the GRID-SIZE-X or "
$ ?5 I& ^. E q' M8 ~ "GRID-SIZE-Y sliders, or decrease the "3 F& h+ f" _, _/ Y- x9 f8 f1 ~4 [8 u
"number of cars by lowering the NUMBER slider.\n"7 j+ c- O( _" I3 F# n) @& ]' y
"The setup has stopped.")) _6 O) {) F$ `
stop4 [( X, c+ e1 @4 f2 F4 F
]
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0 i, W4 ^# I4 _2 H ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color! P; J/ I- u8 D! F
crt num-cars# V# d1 q# N, M" y. V. c1 G
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setup-cars E& t! Y5 u2 C
set-car-color
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2 P; | T6 ^; J o+ f ;; give the turtles an initial speed6 L7 u- G) c0 x' Y6 A; c: s
ask turtles [ set-car-speed ]
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3 } U$ u6 h1 I reset-ticks
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& ?! ?' s% O4 d2 `+ d2 E;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
- i& j) ~/ v- }& R; T set phase 0/ e8 I7 J/ V; O! b
set num-cars-stopped 0; M2 L1 S0 L! X; U+ r
set grid-x-inc world-width / grid-size-x
% I% |* n. \# g+ ^) p8 `4 n! J 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) y3 h/ f: i3 [; q/ b/ S
set acceleration 0.0998 p2 H4 k" ?. n6 Q4 N9 O0 ^
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
% h7 ], ]& j, u4 m;; and initialize the traffic lights to one setting4 R& R% U6 \) j1 m# E
to setup-patches6 h; o3 Y; C1 \! k( h4 Y
;; initialize the patch-owned variables and color the patches to a base-color
4 P4 M6 Y* c2 ]9 J, c ask patches
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set intersection? false7 i; A; B% B* B' b' A
set auto? false
* V- L% H7 {. Y( I; Y set green-light-up? true
( v+ i* Y/ G z) ]0 @' R set my-row -1
c( ~( K* D# ~ set my-column -1
+ Z9 Q1 C/ E( w- M$ d set my-phase -1( f1 S5 y6 Y4 q$ P# c1 U& l r
set pcolor brown + 3) g" o$ I3 K0 D f, J' h
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;; initialize the global variables that hold patch agentsets$ \* @/ o6 q4 y1 \: X
set roads patches with% A0 B( v1 c" ?5 \, q$ F9 \
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or$ K9 f. ?, I9 B
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]" R% g% T9 q) G9 K( v/ |
set intersections roads with
0 a- @8 W; c8 K [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and _0 ]4 [: I8 D/ Q. b
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]( o' J6 a6 G8 s5 g' N* |
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ask roads [ set pcolor white ]/ Y9 `' x+ U/ A9 e+ p1 Y" J! i$ \
setup-intersections
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& b6 g( E. K( U: e其中定义道路的句子,如下所示,是什么意思啊?; |' k& y' B7 ^9 a6 d. x
set roads patches with
1 x N; `" m: } [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, Q' j4 s' C) U5 s% [+ W" n
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 Q( H3 _# p$ s0 ?# b6 g
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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