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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。
" M2 j* V4 @7 n9 u; Wnetlogo自带的social science--traffic grid这一例子当中," I8 f! u1 o7 t3 f0 I5 {
globals; _- M8 e6 _' h4 L7 E! N& ^
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( z4 x; J: E+ h' W5 T) U2 ^ grid-x-inc ;; the amount of patches in between two roads in the x direction" J1 c; s8 p# ^" M R" S1 i
grid-y-inc ;; the amount of patches in between two roads in the y direction5 |2 D h/ y( n0 J( w6 Z$ y# k/ T2 Y
acceleration ;; the constant that controls how much a car speeds up or slows down by if: Q6 k* |1 @& ^% Y3 d
;; it is to accelerate or decelerate
" u; E) ]5 g3 q3 S- j- y phase ;; keeps track of the phase
: `) L% a( @: J) L9 R, [4 M+ S' k0 ` num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure8 q6 _- n% m* s, x& G
current-light ;; the currently selected light8 f/ b/ Q4 J: m4 T) r" y
4 @( A: p" Z. W( C7 d ;; patch agentsets
/ E4 S# |7 f0 q+ Z' [. B$ T$ P intersections ;; agentset containing the patches that are intersections! w8 h# H) B: v7 x) X3 y1 E# E
roads ;; agentset containing the patches that are roads. ~- D7 z4 O6 k# o" C
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4 @3 M3 g. a5 r% _7 ~0 j9 H; s" {turtles-own
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9 {! k7 m- b: ?. f7 o! w speed ;; the speed of the turtle
, w4 [9 M+ v# m( D* b/ b7 { up-car? ;; true if the turtle moves downwards and false if it moves to the right) f1 o$ V) k9 z8 v; ?
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
% s: M/ Z# `! |9 N F; P% C: D! v green-light-up? ;; true if the green light is above the intersection. otherwise, false.
6 U q/ J, L8 B/ Y5 U( Y' V' ~ ;; false for a non-intersection patches.
* u2 e4 e4 r8 @- q: ?9 q my-row ;; the row of the intersection counting from the upper left corner of the
% m, t, I0 A: q ;; world. -1 for non-intersection patches. \! _ `) y K4 _3 }
my-column ;; the column of the intersection counting from the upper left corner of the
1 q1 W: W" {! Z5 L8 r9 G+ ~ ;; world. -1 for non-intersection patches.
0 e, y1 H" D# n1 u a1 n my-phase ;; the phase for the intersection. -1 for non-intersection patches.
+ n, ]! |( B, g: U auto? ;; whether or not this intersection will switch automatically. f1 q! z) P5 K2 b P1 I" M$ ^
;; false for non-intersection patches.0 I) L Y5 ^& v C
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;;;;;;;;;;;;;;;;;;;;;;
" x, [5 `/ a" H; A" {;; Setup Procedures ;;, }# v+ O9 F' S3 `$ t& Y* F
;;;;;;;;;;;;;;;;;;;;;;5 z- i) J i2 H( U
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;; Initialize the display by giving the global and patch variables initial values. D$ M; f6 H9 f, y' G8 m
;; Create num-cars of turtles if there are enough road patches for one turtle to$ z) U- s! d% d% P- Y8 X+ }1 A
;; be created per road patch. Set up the plots.4 z: B- |2 G9 f; p0 a
to setup7 s( d, K$ s* N+ P" r) X4 L
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setup-globals- d, U m' ~' c9 x* @# B
& }# _$ A( X L+ C* T- I8 W ;; First we ask the patches to draw themselves and set up a few variables" x- M. {2 t6 x8 D/ _& H1 z; x
setup-patches4 T& ^7 ^4 U: t9 M) Y1 l# f/ ~
make-current one-of intersections
5 U( c' C# A; P label-current1 b% r1 F$ c" U7 d0 k
# L9 Y1 u1 a: O- Z$ ` set-default-shape turtles "car", U1 Q$ t% d9 L w0 ~
2 o9 Y' Y) `' [/ z6 O if (num-cars > count roads)2 ]3 x1 O2 c% N+ M- f2 Z! X
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/ y+ c/ B `# d; n. ~/ W$ O! l user-message (word "There are too many cars for the amount of "% k# d; u# J1 I- m. q$ }+ {- g
"road. Either increase the amount of roads "
B( I7 l, r) w, X. _ "by increasing the GRID-SIZE-X or "
9 J' ~% x1 l5 ^0 M. ?6 N- W! D: v "GRID-SIZE-Y sliders, or decrease the "/ r! E* z+ u/ n
"number of cars by lowering the NUMBER slider.\n"
% u Q( i1 J+ J% N7 E; u "The setup has stopped.")' C, s* @( @$ o2 _
stop
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0 {5 z7 r _# @) c& v7 f; r9 I: o4 t ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
0 z4 J9 r' R: `' z" C$ c* O crt num-cars7 t$ g( x* O* h, B" E5 {( ]5 t
[
$ k4 s6 T' t" ~ setup-cars
. @3 Z z! f1 I; h# x. { set-car-color
- I7 ^. Y+ t, R0 @+ d4 [, n5 ]5 e record-data; m, I- L r7 B# W' @' r$ t
]
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7 Y0 q. Q7 f% ], l2 F/ e ;; give the turtles an initial speed
6 `- f2 H. K/ V5 X ask turtles [ set-car-speed ]
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reset-ticks% l. D- [& Q2 k) X$ o' {5 O
end! H3 I, s% R! Y" V
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;; Initialize the global variables to appropriate values& G. b( V; v. y. N4 n9 I; l1 u
to setup-globals- X' ]! X; g' i
set current-light nobody ;; just for now, since there are no lights yet
" T" B$ T* q( I! Q+ ~% w set phase 0
- o5 o/ S/ `5 L/ [+ s set num-cars-stopped 0
% S% u$ S1 G2 l8 i set grid-x-inc world-width / grid-size-x
: }) r0 C8 A8 z, h; @+ n2 F K set grid-y-inc world-height / grid-size-y# V& L+ D; S' e z n- u4 Q
% v, q" o4 r$ c$ B- D6 y& t+ \ ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
! t, u+ N h; _9 ?6 t# W$ O6 a set acceleration 0.099
! n7 a3 o8 z1 \5 ]7 G* M zend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,8 R, n" b/ q& H! F
;; and initialize the traffic lights to one setting( W1 [% L$ Y% S, t1 F6 N
to setup-patches
7 O5 J' y/ s2 C ;; initialize the patch-owned variables and color the patches to a base-color
0 {* ^5 ]" y$ }8 `) f6 a0 r1 ? ask patches
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set intersection? false, S. {- T% {0 t4 x
set auto? false% B+ s" S' |" O3 r! q3 ?5 g
set green-light-up? true
/ G% I# w# ^( B6 J set my-row -1) O; `# C8 b8 L+ t8 p3 B: p
set my-column -19 B6 t3 f2 @# V: T8 @* Z8 |
set my-phase -1
) @8 I( }! }9 O7 ?4 A) V% k/ H set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
5 b( b ?( E' m9 q7 a; R0 N& \ set roads patches with
9 M1 h8 g# |1 f" f$ z6 p [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or6 `( f2 F! |( g- A7 o$ P
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 B8 a. M, [0 P( O
set intersections roads with7 G2 c! ]1 x, H
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
3 f( Q; {4 Z$ D (floor((pycor + max-pycor) mod grid-y-inc) = 0)]- S" [* p0 Z7 K" T& W N1 ~
. b2 L( J, s& V' j. v$ g+ u0 { ask roads [ set pcolor white ]0 `7 Y0 m I4 k d5 M
setup-intersections
% i- A' R; v" I3 A% h2 B kend
; m, ~' {! ^3 {' g% `" k其中定义道路的句子,如下所示,是什么意思啊?
7 X* I) s# X& O( s) v" @0 S1 e! t. D, Z set roads patches with
$ o8 ` v, ^; `8 k& f+ I6 ~ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' J* o2 o5 ], K5 Y* G
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' g4 ], m/ q, H# t" \# Z% F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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