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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。7 ~2 I K0 m) m6 i+ h
netlogo自带的social science--traffic grid这一例子当中,
& q; Y+ R' e- Pglobals; ?: P( l1 R$ T! J# `
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0 B; M. w1 H) b+ V. b grid-x-inc ;; the amount of patches in between two roads in the x direction& J, e. O$ e$ \1 K& F
grid-y-inc ;; the amount of patches in between two roads in the y direction. Z5 ]# p1 C4 y [' C1 f3 Z
acceleration ;; the constant that controls how much a car speeds up or slows down by if9 d+ J4 V2 q0 w" [7 v
;; it is to accelerate or decelerate6 b% U- W) _8 P }9 {+ E' A! w! Z
phase ;; keeps track of the phase
, k% b* l$ H: u num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure' \& j; H$ G" s
current-light ;; the currently selected light% J6 @: R5 f- A, Y0 X% h4 Q, v. F
0 Q9 U7 w! G0 f# r2 |# w: t) ?, D ;; patch agentsets
# n: ^4 \8 O: [/ } intersections ;; agentset containing the patches that are intersections0 m4 G6 p! m- T* }0 S0 Z
roads ;; agentset containing the patches that are roads8 k3 P$ o6 |" G7 D b6 _4 b
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turtles-own
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4 N6 B2 n+ w5 e" \ speed ;; the speed of the turtle
% o9 s0 P9 D1 N3 i$ I1 l Z up-car? ;; true if the turtle moves downwards and false if it moves to the right& n. [: Z. i9 e; ^/ E5 f
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own) P# J& A$ {1 M7 a( `. l' C
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5 T( A* y. [/ F: R0 N$ ?' d intersection? ;; true if the patch is at the intersection of two roads
, _3 n* D6 h! _" E* W% A green-light-up? ;; true if the green light is above the intersection. otherwise, false.
9 o" f: w, n0 I8 U ;; false for a non-intersection patches.
) [/ |9 l2 j1 l my-row ;; the row of the intersection counting from the upper left corner of the# S& C9 Z0 U) D; n: W _7 e
;; world. -1 for non-intersection patches.' m3 c/ _6 \( k5 o$ n4 p7 U$ |3 `
my-column ;; the column of the intersection counting from the upper left corner of the
4 Y5 j! p& }/ z f& v- b, j ;; world. -1 for non-intersection patches.' @3 |7 b; ~8 {0 ~3 S/ J6 B6 U
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
9 t1 ], ~. A) R( @ auto? ;; whether or not this intersection will switch automatically.
. {( G9 S3 E/ }6 K ;; false for non-intersection patches.
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1 I z0 ~: u* k/ g. K;;;;;;;;;;;;;;;;;;;;;;
5 V2 j1 ^& ^7 g6 ~;; Setup Procedures ;;
) v4 Z: ]1 d1 R3 V0 _( @+ W6 };;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values./ j: k. v, E- q* \- Z
;; Create num-cars of turtles if there are enough road patches for one turtle to( P# S/ @6 v [
;; be created per road patch. Set up the plots.. I9 @0 u7 ~; }* {% m) W. \
to setup9 z$ K* l Z# w' ?: k
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setup-globals
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9 F& u- z' v: A/ n( D9 E9 ]1 \ ;; First we ask the patches to draw themselves and set up a few variables
9 T7 P! I& N/ J setup-patches
) l4 w* M) S$ R4 T/ H' Q2 y [9 N2 G make-current one-of intersections+ n1 M: Q+ r0 |/ f+ x# S4 d9 S# _
label-current6 r, K+ A; [" E/ ]4 | b0 s% k/ i
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set-default-shape turtles "car". l# d! R; k @+ `
. X$ q+ A% X* T if (num-cars > count roads)! `! Y- V0 G; T3 O
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user-message (word "There are too many cars for the amount of ". K$ t+ }7 J1 i* ~, M
"road. Either increase the amount of roads "
7 l2 u( R( [. d "by increasing the GRID-SIZE-X or "
# T) _( p6 f& @ J ]% c9 ~ "GRID-SIZE-Y sliders, or decrease the ") e3 c) o$ n7 L6 Q' P
"number of cars by lowering the NUMBER slider.\n"
8 n9 d) F$ }0 Y" X) W "The setup has stopped.")/ Z* H6 N' B- S
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
$ H& z- W. a% V- T crt num-cars
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setup-cars/ H% H# s& z4 N
set-car-color# z- b* l& w+ N/ [+ M- U
record-data
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, M, x4 f6 R9 m& ]( C$ A0 c& C0 O+ o8 o ;; give the turtles an initial speed
# @0 T f+ |) a$ c ask turtles [ set-car-speed ]+ Z8 U% m# c2 t
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reset-ticks+ f3 J, p! `1 b! ~; ?
end! v3 l/ q3 ? S+ R% _
7 h! ?& L% }1 ]6 I! t% X;; Initialize the global variables to appropriate values0 P5 `6 m7 L2 U2 ]
to setup-globals4 J/ J+ ?( i# O. n, H1 w6 B$ D
set current-light nobody ;; just for now, since there are no lights yet6 ?7 w1 w2 T# Z, H
set phase 0
3 b6 X6 ^' Y" R# |/ e8 T0 K set num-cars-stopped 0
6 l/ V3 H9 \: N7 F, V set grid-x-inc world-width / grid-size-x
! v7 z% I6 ]: l0 _ 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. s' {- p9 E a/ x( {1 o
set acceleration 0.099- x% s% j: O# G3 n! p) n: L9 w/ e- F) k
end+ e. P3 |$ c' T, w, S
# m! l( E" Z% U% e1 W;; Make the patches have appropriate colors, set up the roads and intersections agentsets,8 l6 q' k' W" m {# q" S6 R
;; and initialize the traffic lights to one setting
) v1 s9 u' x: Ato setup-patches
7 o, x+ ]1 r2 t: W0 t9 s# | ;; initialize the patch-owned variables and color the patches to a base-color+ w! @( u. F8 u* p+ r5 u) w) ^
ask patches
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- S* _$ E% J1 k/ d( k1 y set intersection? false# a$ _9 o0 [+ A1 W0 K, }
set auto? false, `* J( Z1 p7 K) Y; f5 p
set green-light-up? true
( Z; t/ c, }+ ~3 R6 p set my-row -1
8 N5 [: k8 G& L0 ~ set my-column -1
- L- g8 j' q- H; s; r+ n set my-phase -1
' O$ M4 E0 J3 K set pcolor brown + 3' A. w( h. O+ B- i
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4 U) y. W X+ J ?- A8 s% n9 W ;; initialize the global variables that hold patch agentsets% z v, C1 p9 A7 J( c
set roads patches with4 N) B0 b" b' L
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; }8 B8 S) |! l& L: K1 ` (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# {0 U2 q, F& U9 Q set intersections roads with
5 }; M* U: X8 y; d/ Y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and. q/ P$ i! o" ?; r
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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( b. R# R/ m: F3 Q" I/ i ask roads [ set pcolor white ]# \; \. K+ u$ y) s7 @ a
setup-intersections$ n9 D0 U6 E2 r
end
3 V: k5 y( T- Z8 e% l" K8 [/ W" z其中定义道路的句子,如下所示,是什么意思啊?4 |9 g3 S4 L q c% m2 @' d. t/ O
set roads patches with
! i. w3 P' O! S2 m [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 B$ F7 f( X; K% v0 Q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 u- ~$ Z5 O3 W C4 X" O- D& S A- t
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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