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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。. g# e" Z% ?" d3 I7 w6 |
netlogo自带的social science--traffic grid这一例子当中,
, Q% Y1 J0 C+ Gglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction6 \/ |2 t; ?0 \, _) T) Y# R
grid-y-inc ;; the amount of patches in between two roads in the y direction! B C+ g' t/ C+ A' @! F
acceleration ;; the constant that controls how much a car speeds up or slows down by if
7 ?- r4 Z9 [' A0 x J" f ;; it is to accelerate or decelerate! @& |2 R0 K. i5 g! L" V2 g1 g
phase ;; keeps track of the phase
, l1 N, L, Q9 f- r9 ?% d+ ^ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure# Z# N. j/ ]0 f# [* Z% U* N
current-light ;; the currently selected light
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: s' H5 a% k: W2 \ ;; patch agentsets
! R' c+ C% f7 G. G7 n7 J( l! s intersections ;; agentset containing the patches that are intersections
9 {& Y4 h& Z4 u! @ roads ;; agentset containing the patches that are roads
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5 a3 f, r5 P) k4 n+ p/ @4 Pturtles-own5 p5 }$ q2 e* @1 T7 x/ J/ b
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) ~- p. P4 e3 }( f G8 _5 G speed ;; the speed of the turtle
6 b; H4 }8 {& K# `: X5 G up-car? ;; true if the turtle moves downwards and false if it moves to the right
$ z: D% Y. @9 j( A wait-time ;; the amount of time since the last time a turtle has moved( ]0 c8 r, n$ ~
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
* z8 ~2 c- o! E- L$ \% \* O0 @1 j green-light-up? ;; true if the green light is above the intersection. otherwise, false.( x- s; J1 N8 E" b
;; false for a non-intersection patches.
9 g6 U# ? c. `) h+ D% c1 q my-row ;; the row of the intersection counting from the upper left corner of the( v# ?' ^% q# `$ C k
;; world. -1 for non-intersection patches.
. r* y7 J; f' Q4 n5 ~5 q4 n9 I my-column ;; the column of the intersection counting from the upper left corner of the4 Y0 y: x5 y5 N6 G8 R6 J/ \
;; world. -1 for non-intersection patches.
9 _: _7 J+ ^8 i" A7 L my-phase ;; the phase for the intersection. -1 for non-intersection patches.3 D" p! c! _& V( l" W+ Z
auto? ;; whether or not this intersection will switch automatically.
3 E7 K. |3 P! | ;; false for non-intersection patches.& |% ~& p; ^8 s2 I% [& n7 x4 s
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;;;;;;;;;;;;;;;;;;;;;;. C1 S2 h5 Y. {8 l7 { @7 x
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
4 j9 _- J/ ~$ m) z+ B! C3 q) z U+ R6 [;; Create num-cars of turtles if there are enough road patches for one turtle to+ e. W& h% u' S, P1 i
;; be created per road patch. Set up the plots.8 Q2 e4 W0 D8 {. p
to setup' P. Y, J# F, R" I- l
ca
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;; First we ask the patches to draw themselves and set up a few variables
4 C' F* @. b/ P setup-patches1 O w# e& i6 W1 T; Z8 T
make-current one-of intersections4 {( H% X) v* k# z B) E+ g, U
label-current9 s1 `2 M4 [, g0 p" |
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set-default-shape turtles "car"
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5 \* P" v! e! L5 P3 f$ I8 H% }) R if (num-cars > count roads)( C o/ F# p" A5 n4 {
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user-message (word "There are too many cars for the amount of "
( ]. e( l5 y" H, N6 E "road. Either increase the amount of roads "
+ }1 P9 i$ ]. y4 K' ? "by increasing the GRID-SIZE-X or "
# O0 ^: X) @0 k' H' h "GRID-SIZE-Y sliders, or decrease the "
' E. f. X5 j8 P4 r( h "number of cars by lowering the NUMBER slider.\n"9 J$ R) \5 n) w) G7 ]7 c
"The setup has stopped.")/ p# Q* q, U! P3 T' \
stop
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1 x- f; k8 M* K. M# {/ ? ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color2 H7 I' `' m* K$ O$ t
crt num-cars& F5 y1 N, T1 A2 J! B& h( S' {) K* N
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setup-cars
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. |: A, F* O, l/ q2 o- \ record-data
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! T9 q' }2 |( Y4 t# Y9 l$ P. X9 p ;; give the turtles an initial speed
' o% m0 `4 X# o; O: o, V/ ^% S3 R) p ask turtles [ set-car-speed ]* n$ V2 l9 V7 c( Z: ]5 c2 H
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reset-ticks( y% S- j6 b, {7 C
end
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;; Initialize the global variables to appropriate values3 G' j4 O5 h* c
to setup-globals* W- G3 j& d, X/ h8 n0 f2 t
set current-light nobody ;; just for now, since there are no lights yet( N+ i0 @6 ]; \7 w
set phase 0. F! V* _7 [! C; i ^& C4 L. E, T2 ]
set num-cars-stopped 0
1 q/ C: }4 Q( i( D set grid-x-inc world-width / grid-size-x; o; y) H2 T9 \% a6 }8 R1 w; a
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
& c, f q6 }! M set acceleration 0.0990 C" j/ o4 c1 P: I3 T
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,7 m3 m$ g1 x6 @2 W
;; and initialize the traffic lights to one setting
; u4 I1 d: K& h Z: a: s& G+ r4 g) Xto setup-patches
3 [2 ?3 i$ x9 L- H, A) W2 g ;; initialize the patch-owned variables and color the patches to a base-color2 i1 ^* x0 Q) Z: l! a
ask patches
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set intersection? false
( Q' `( s6 D5 k5 O# F8 s set auto? false
6 q8 k& l, X& K) R" Y. g set green-light-up? true
% Y: I# e2 w: v: F, X set my-row -1
$ x% g1 s; {% F set my-column -1
- d3 P- M2 E5 k" Y! l; R set my-phase -1
' i E4 y8 M# a0 @9 ~ set pcolor brown + 39 @* {, h$ G l. A4 ]. L
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;; initialize the global variables that hold patch agentsets
: a0 I6 x6 g3 j6 G set roads patches with
! |# @& |) |- ^% c2 z+ i) M& S [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
, T( c1 _/ q7 i4 o9 |7 |+ ]: D (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; ^5 l7 w9 p Z
set intersections roads with; [& k0 g5 Y6 l! O: J
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and9 }$ K: h& j' A$ u
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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: I& w* V* [1 |# [0 }. N ask roads [ set pcolor white ]1 v1 p, k% f; @$ F( L% y! X b+ W
setup-intersections/ Z- j3 L$ [" a9 D: E7 a
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其中定义道路的句子,如下所示,是什么意思啊?
5 \+ R1 N) H$ ^0 X+ U( u* D set roads patches with7 g/ T; [- M$ ~
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" }7 P$ o/ A5 ^+ P
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 n; U6 u9 P6 ]; w/ b
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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