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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。1 a$ i0 q, U- M
netlogo自带的social science--traffic grid这一例子当中,1 c0 d/ ~$ V. t. ~; x
globals6 y! ~, C, e. w, T7 y2 N8 J
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grid-x-inc ;; the amount of patches in between two roads in the x direction: Y- M- z0 \9 c/ l I
grid-y-inc ;; the amount of patches in between two roads in the y direction6 q& w! @% c2 W2 C; E# F. w; S
acceleration ;; the constant that controls how much a car speeds up or slows down by if4 g* Q, a" h/ A% U% m
;; it is to accelerate or decelerate
4 i$ v, r5 Y' {- \; |0 j, g phase ;; keeps track of the phase4 U, A& p. v3 ` p9 f
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure" B$ a5 O2 l. A l, m
current-light ;; the currently selected light$ }5 _' Q/ y2 I' y! Y
- a# }! [& R; Z! K# L: P) j% W- F ;; patch agentsets; q( D$ @1 H# v; |: M
intersections ;; agentset containing the patches that are intersections
9 B# Z3 O: c) K( N* j roads ;; agentset containing the patches that are roads3 S' u/ ?5 T: \7 t) A5 |
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% [5 z: \4 ?4 t8 `% C, c* m* S2 x0 tturtles-own
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speed ;; the speed of the turtle, x) z# a" K$ @' S6 u1 D
up-car? ;; true if the turtle moves downwards and false if it moves to the right
. t) V `% V5 ~2 c* K wait-time ;; the amount of time since the last time a turtle has moved
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+ z4 ^+ n0 K6 z# R3 N9 d. Rpatches-own
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1 L, ~" [. A9 T+ a, Y$ d7 R- R intersection? ;; true if the patch is at the intersection of two roads3 z$ m- o: C* g N" E- H. ]& z3 v
green-light-up? ;; true if the green light is above the intersection. otherwise, false.$ g6 B; e- M& |, I8 G: o
;; false for a non-intersection patches.2 H. P) l7 X) N7 h, w: {; z
my-row ;; the row of the intersection counting from the upper left corner of the% q+ V8 }2 \3 T- v G, m0 Z
;; world. -1 for non-intersection patches.4 W+ }& t- L' X' a0 V5 l5 k# I
my-column ;; the column of the intersection counting from the upper left corner of the
' M; w5 U$ l4 O* @- _ ;; world. -1 for non-intersection patches.# L4 _( H- G+ n- Y/ w; V( ]
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
- m6 V- j1 {' n9 Z- N) d v' l/ A auto? ;; whether or not this intersection will switch automatically.% P. g* U: z2 y2 d _' O4 Q8 v
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;3 S6 {5 ^& V' a1 c" j
;; Setup Procedures ;;
0 t0 J; \; T0 ?3 E( O2 Y( G;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
7 {6 `7 v2 B8 r" d7 G;; Create num-cars of turtles if there are enough road patches for one turtle to6 A$ U4 i# X: F# q ]
;; be created per road patch. Set up the plots.; z7 b) R: z" x+ N7 K( r
to setup
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: e6 T0 A& q: H O* r# O setup-globals) R* f4 {; N' S2 P
4 R+ N& p8 P! D3 P ;; First we ask the patches to draw themselves and set up a few variables
2 F7 l q' W0 O: t( ~' L# \ setup-patches
" L( f8 b) b" ?1 j3 J. q& I make-current one-of intersections
' k v3 ?4 h8 ~) \" t label-current9 Z: a: k. A9 p5 b: G4 T
6 w- e2 h8 i: N. S! n. G, b set-default-shape turtles "car"
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3 q6 ]* l5 ]) J; U* n- ?8 J if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
3 ]# S# g0 [: S8 Z4 [) P; Q4 ` "road. Either increase the amount of roads "3 n9 T* J4 R0 {) X
"by increasing the GRID-SIZE-X or "
4 |3 G% G7 B- y9 q# K! C0 x+ } "GRID-SIZE-Y sliders, or decrease the " t) K/ W" I5 S' M2 m# S
"number of cars by lowering the NUMBER slider.\n"
, ^0 ^1 E" i# ~; c7 d) r "The setup has stopped.")
3 w$ O. c6 Y6 L# a- u stop i' x' @% P) e& s
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
6 `0 x$ r* U4 t V7 C crt num-cars
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setup-cars' J+ p' P* E! A, [* ^
set-car-color
. j/ k* w" I: \ record-data
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;; give the turtles an initial speed
% @) | b$ a7 a! x5 a) t! O ask turtles [ set-car-speed ]
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' c- i* k: \3 a reset-ticks
4 C$ A0 f+ a$ P( p r$ r' Xend
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;; Initialize the global variables to appropriate values A) @/ c2 p7 f6 x4 C, \4 p
to setup-globals
/ J& D& L, w1 |" F set current-light nobody ;; just for now, since there are no lights yet
1 k: m) N: j$ I set phase 0
3 ]: b# x/ N% d9 @! T- w set num-cars-stopped 0
( {! m5 }% R! K set grid-x-inc world-width / grid-size-x6 D3 h: N% [7 e. _6 a
set grid-y-inc world-height / grid-size-y. v5 M- _5 w! f1 @4 B
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
& {1 r9 t' `. W: D' b set acceleration 0.099
! f4 W4 R! T3 n+ \+ A$ m7 [3 _end- H1 k# R' I5 }: i
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,4 w9 D+ B# x6 g! o4 Q; M+ D
;; and initialize the traffic lights to one setting5 l1 x0 [$ d: E0 ~& o) c& {
to setup-patches9 ]% T! W; N# p
;; initialize the patch-owned variables and color the patches to a base-color
) ^" Y$ M* s3 f$ v9 m" ~ ask patches5 n4 a4 w) ?* V
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set intersection? false
. d) \+ N" m: _ set auto? false2 |9 n' U& C+ y- M: W2 I
set green-light-up? true
' m) D* F( J1 L. |5 ^% k" h set my-row -1
( k- z5 |5 g' u$ }! R/ A2 @ set my-column -1
% c" V; ~: |% @- | set my-phase -1
9 F3 j) X/ t3 x* S5 O3 ^ set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets# `* E" W) ~- @2 w- P4 P
set roads patches with: g2 D5 E8 L$ T3 s
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or U0 I+ n2 P9 m) r, G
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: F# f' Z& ?" u: q E set intersections roads with
b9 N3 v/ \+ e% E3 @ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and5 k; _ R, i5 z H
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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5 i7 a- j# ~$ ~7 k* G) E( B ask roads [ set pcolor white ]
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其中定义道路的句子,如下所示,是什么意思啊?
7 A1 J6 g7 j! H" W7 E. P5 ~ set roads patches with" M& D& `2 n4 \9 K% s0 P+ U7 [( D
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or7 u+ S- |; |3 ^ m! u
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ E) e( Z/ v& Y8 }! Y7 x! }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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