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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。" L3 A8 `( P: p' j& z
netlogo自带的social science--traffic grid这一例子当中,
; \2 v+ r4 H; z) D ]globals
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' K! K) ]/ F0 I8 q6 _9 ]2 x grid-x-inc ;; the amount of patches in between two roads in the x direction) ~1 }0 }$ @! k$ j. y4 G7 ?
grid-y-inc ;; the amount of patches in between two roads in the y direction
q4 t5 X% u! I$ {/ S" | q acceleration ;; the constant that controls how much a car speeds up or slows down by if
; K% ~6 ~) ^2 H4 }! @# r ;; it is to accelerate or decelerate
z5 o7 `- G- H0 B phase ;; keeps track of the phase
& f& y8 B% F0 s; I2 _ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
( l7 `/ g( C/ w; f current-light ;; the currently selected light
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;; patch agentsets3 {9 K" s2 V7 T# W+ s7 p& `6 F
intersections ;; agentset containing the patches that are intersections. w. N! w' z! n0 N4 d. J8 L
roads ;; agentset containing the patches that are roads) @+ R+ N" _1 Z* L, }
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4 C2 f# ~) W8 x, T. Bturtles-own, q4 ~: G- X @% a3 a% B
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6 n& O' V7 e" _# I speed ;; the speed of the turtle0 r2 O" s& ^ F/ }9 x* T
up-car? ;; true if the turtle moves downwards and false if it moves to the right
" z2 y. `( Y& B; S4 Q wait-time ;; the amount of time since the last time a turtle has moved
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! I! h/ K! K2 h6 bpatches-own
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% P7 J& K; E# K5 F/ D intersection? ;; true if the patch is at the intersection of two roads
6 ~* E( w4 G7 N7 e green-light-up? ;; true if the green light is above the intersection. otherwise, false.# F6 x# Y. L# i/ I1 o
;; false for a non-intersection patches.3 W2 l3 h( o& |3 F. _: e. y a5 r
my-row ;; the row of the intersection counting from the upper left corner of the' \7 z1 `% n& e( p `
;; world. -1 for non-intersection patches.
}4 ?. g2 h3 f7 n' L1 _ r) M* N my-column ;; the column of the intersection counting from the upper left corner of the
5 D6 S+ p* D0 y ;; world. -1 for non-intersection patches.4 X% z0 F P0 a, X
my-phase ;; the phase for the intersection. -1 for non-intersection patches./ K* O/ D5 D4 v, \5 f- m1 r2 s
auto? ;; whether or not this intersection will switch automatically.. G7 C; y$ Q( d+ D
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;: B8 W& m% N& K9 H# R
;; Setup Procedures ;; i2 J& c/ B- j9 |" |
;;;;;;;;;;;;;;;;;;;;;;
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* u, J& R0 o! h9 f+ U! ]4 @- S& C;; Initialize the display by giving the global and patch variables initial values.
7 X. f3 L% \: \. {;; Create num-cars of turtles if there are enough road patches for one turtle to: y, r' m- l: R/ P
;; be created per road patch. Set up the plots.! Q& ~3 p( E! U9 T; R
to setup
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setup-globals/ z% l( g. l8 }! i
* X; ]& d. w. v! \0 A0 M! `% ]9 C1 U ;; First we ask the patches to draw themselves and set up a few variables
1 b {+ G" @3 b/ i3 u setup-patches1 Z) `) o2 F* Q2 P. f
make-current one-of intersections' @3 ^2 A0 M5 }1 W' }
label-current( G. {9 R/ a+ ^0 p/ v% q$ Z" ~
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set-default-shape turtles "car"
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if (num-cars > count roads)" j# h) O: M( j" T( e
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2 ^; ~, `) V* [$ I8 D" T6 |- h# |/ U user-message (word "There are too many cars for the amount of "% i* h% L& y: C& o8 e8 Y
"road. Either increase the amount of roads "
( [5 i; d- L# @2 B1 J5 J3 l "by increasing the GRID-SIZE-X or ", @- [# N; p% M% k
"GRID-SIZE-Y sliders, or decrease the "$ k8 v# `+ z* |) r' |
"number of cars by lowering the NUMBER slider.\n"
" T: T5 A6 r8 G* a "The setup has stopped."): }5 u, H- s( o9 e1 x
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
' a T6 a; g: _6 |, T crt num-cars! h0 o# I4 G U% H* p! W: A6 p
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setup-cars: ]% x. D3 U0 K6 I3 b2 R
set-car-color
4 j8 ?: p1 C; y) |) C9 B1 w record-data
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;; give the turtles an initial speed
7 f) F' c: Z8 k0 m$ D4 i4 U ask turtles [ set-car-speed ]1 g' j$ q! Z5 f1 q
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reset-ticks
, c3 D5 H# B% V+ C' u3 @end
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1 R8 M/ l4 Q+ @0 u9 c, l;; Initialize the global variables to appropriate values' N0 \5 Y" Z( P& J
to setup-globals# D6 A; J/ t+ y# H1 A) O
set current-light nobody ;; just for now, since there are no lights yet
Y* ^: z; g3 O( V set phase 0
& t5 l" a$ f, Y, ]& I set num-cars-stopped 0
, s) y1 J k) \, J- p" J: ] set grid-x-inc world-width / grid-size-x& X$ J$ V% Q9 F% e( S* ~
set grid-y-inc world-height / grid-size-y: Q* c1 s. @& u8 {: B. d) 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
- i' v: w% I# c set acceleration 0.099
* ~' p7 N4 t& }end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
8 x, `( H7 i4 i. V# N) b! v;; and initialize the traffic lights to one setting- p' m* ?% A/ A* i& D
to setup-patches/ ?/ Z/ B% F6 X1 W0 k* N" B: K% ]
;; initialize the patch-owned variables and color the patches to a base-color
6 P+ h: H; ~8 u9 ]$ g# e- ? e+ s ask patches6 K0 |0 X Y6 i0 X1 U3 s
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1 M- \1 {, ~: x) K j! z8 V7 z set intersection? false: ~; F* A1 A: n0 _) M. G$ R
set auto? false# {/ r; F! p- W8 \. h8 E2 N
set green-light-up? true+ I6 T5 J, E1 x- S' `2 w
set my-row -1
, `7 r' M3 Q! {4 E5 T6 K set my-column -1
& S o, ^% G2 Z v6 S. s. d0 _6 r2 p set my-phase -1$ |+ F/ y6 v8 q/ E0 F" T
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets6 n/ W( c$ f0 }5 W1 l w1 F* H
set roads patches with
- K' B3 Y% i; |, \! z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 R5 y4 S" r1 ~ A0 k& u
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 e! ~$ q' z# N" Q
set intersections roads with1 C# h) d" Q) a5 m, h1 i v
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and* x! ^7 [# o2 b& L: q9 @# @
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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/ M0 |3 a2 ]9 v$ u% G1 m" B ask roads [ set pcolor white ]" [$ `- M6 V8 L. G8 v* [
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊? p# m P5 D8 v0 V* E0 P0 ]
set roads patches with
8 e8 J# K7 H# [2 K7 I, Z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ c. j% P7 V1 x/ y$ s (floor((pycor + max-pycor) mod grid-y-inc) = 0)]! _5 m! X8 o0 E% N4 Y
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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