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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 h# K; ?1 R! D1 m0 Anetlogo自带的social science--traffic grid这一例子当中,
3 G$ M6 M- @: s: x: {3 D. ^( G. b6 wglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
! Z- z2 {+ @9 x6 H% u" A+ G grid-y-inc ;; the amount of patches in between two roads in the y direction( s4 C4 `/ k' |- v7 \$ e
acceleration ;; the constant that controls how much a car speeds up or slows down by if2 |9 _* M2 w$ [' A
;; it is to accelerate or decelerate+ Z1 h1 R: d7 e1 d1 L6 Z* [- y
phase ;; keeps track of the phase. T5 Y! l9 K1 |! W( V3 u# Y
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure; D6 P& x- O& U3 ^
current-light ;; the currently selected light
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2 C0 c4 a. q ]/ T g ]7 z ;; patch agentsets) x. s$ j$ `: y5 G9 e( Z
intersections ;; agentset containing the patches that are intersections
- c* T1 Z; G; L' w1 X2 i8 _ roads ;; agentset containing the patches that are roads! p% B0 r* G3 l0 x2 k) Z
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: G9 d$ E; B& kturtles-own
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+ R: U. a) S0 G8 s" j) P speed ;; the speed of the turtle
, f" U% V& @' e, f/ P up-car? ;; true if the turtle moves downwards and false if it moves to the right
# P- L8 W. w* J# B4 T5 P wait-time ;; the amount of time since the last time a turtle has moved
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e$ t. P$ F O2 o$ i2 }, mpatches-own5 N6 c A' S" K4 P2 W7 U
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0 g% {4 ~ c V intersection? ;; true if the patch is at the intersection of two roads. K9 d2 A. R; l+ {
green-light-up? ;; true if the green light is above the intersection. otherwise, false.8 ?$ o( T9 { X" F
;; false for a non-intersection patches.2 _4 M& x D0 l5 {* E% e4 W
my-row ;; the row of the intersection counting from the upper left corner of the. U4 n: W# c a5 ]
;; world. -1 for non-intersection patches.
" Z. B; S2 s9 D9 Z+ f. ` my-column ;; the column of the intersection counting from the upper left corner of the2 p# u' M! [9 x( Z
;; world. -1 for non-intersection patches.
) _. ?- A/ {( U. l" M my-phase ;; the phase for the intersection. -1 for non-intersection patches.! s, A7 q' s, i
auto? ;; whether or not this intersection will switch automatically.! g1 q% x2 _0 ^
;; false for non-intersection patches.9 x! J+ w+ d; X" Z$ } X. m" E! D
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* E1 S7 f* K8 C;;;;;;;;;;;;;;;;;;;;;;' U( _# e5 |7 J4 ~1 P% X
;; Setup Procedures ;;+ t6 I# E; Q/ ]. S
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
( R' M' k/ a1 Y% u' G7 F;; Create num-cars of turtles if there are enough road patches for one turtle to4 u5 H, ]/ Q/ N; n0 _
;; be created per road patch. Set up the plots.
% M" i& V' I8 C' Z% Cto setup
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2 G a$ |% p3 Z: J$ w1 I setup-globals" n) h: p- N$ e4 r1 g6 U6 P! E
; S% x9 ]) i8 M3 x# E ;; First we ask the patches to draw themselves and set up a few variables
& f7 y3 s4 A. d, k setup-patches
1 f. u* K8 `; \7 G make-current one-of intersections
' l: d4 c: W1 W2 V7 W: t6 v label-current8 {& _5 U+ u7 b7 @" P
) u( Q- g# z2 j- r9 N, [ set-default-shape turtles "car"2 q; t H8 j: ]2 O
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if (num-cars > count roads)
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, S( X1 H& u. @# j: P user-message (word "There are too many cars for the amount of "5 p( H: G) F, |( u5 ^% K7 `
"road. Either increase the amount of roads "
) L7 o" P" _# g. x9 w "by increasing the GRID-SIZE-X or "9 I; p% R- g9 a' C
"GRID-SIZE-Y sliders, or decrease the "
) ^' a! W- z2 {9 a "number of cars by lowering the NUMBER slider.\n"9 B8 u' b! y8 R+ W
"The setup has stopped.")
# y [+ ?8 X& L. x7 o stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color6 f9 @2 ]- \6 s; c+ e
crt num-cars0 j" W8 l0 x6 y" ^
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setup-cars! {# k) ~( r0 ?4 X' C4 i
set-car-color
$ F6 E3 | T) W" J6 G+ r record-data
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# N0 e+ ]* t( s2 h0 l' ~( x ;; give the turtles an initial speed
: ]9 e0 ?! G( q ask turtles [ set-car-speed ]3 W0 c7 }+ z. a# E% m
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reset-ticks$ C3 n4 v! O0 n1 g
end
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1 f' H+ v# l4 @/ H& M8 W7 ?;; Initialize the global variables to appropriate values
9 W7 V/ X3 F- Y5 ?& u+ I9 [to setup-globals1 ^5 P/ E1 K7 E
set current-light nobody ;; just for now, since there are no lights yet
8 Y ]9 f; x% F# M, Y set phase 0
1 h4 R4 _1 H, x set num-cars-stopped 0& N( F' n: Y+ s4 w: f2 Y1 q9 f% Y
set grid-x-inc world-width / grid-size-x, j! s- j. ?& G: u. b
set grid-y-inc world-height / grid-size-y0 ?6 p) t$ U% l
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
8 I% Q+ v# }: ^" X set acceleration 0.099
& R) q. D( P9 i- Q* Pend
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) o/ O. M9 A7 o3 r8 d& m% m5 d% a0 r9 n;; Make the patches have appropriate colors, set up the roads and intersections agentsets,+ t8 {6 s8 o3 d+ v, Q
;; and initialize the traffic lights to one setting
2 a8 J% m/ F" h$ @. ^, g# v, b' {4 sto setup-patches
4 M9 N. `! w. }+ w; ]; H ;; initialize the patch-owned variables and color the patches to a base-color
! m& P3 k# n i6 @' N' ? ask patches$ }7 j' J$ j& l6 e% } h4 Z& i
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set intersection? false( y# F3 v4 s+ b1 K& Y
set auto? false) N# L/ h9 t0 T% L [' V
set green-light-up? true
& g5 c, n& B. S d F, h% I set my-row -17 t" o0 c! V* C! {: M; l. s* m7 N" c
set my-column -1
' H4 |( v* Z! l* f* |9 E set my-phase -12 m; L: z$ q1 m; f: E
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets# J; Y' `+ K& Z0 {' M* T
set roads patches with
' k0 F/ c# h0 a. f- Y4 Y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ d0 j; `9 X1 e) s( ? (floor((pycor + max-pycor) mod grid-y-inc) = 0)]* n8 d# o9 v% q8 p# R# W$ X9 d
set intersections roads with; w( ]- p; j Z( Y/ c- ]1 U
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and0 f2 c" P: k! m1 m) ~
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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6 w; U0 {0 b" w) N6 K8 @) U ask roads [ set pcolor white ]
8 ?- p- c, T( E setup-intersections" j4 e0 u0 }7 p- k F
end
( G8 v' b5 W7 U6 S9 W其中定义道路的句子,如下所示,是什么意思啊?
, H" S$ J+ z0 d! l; k0 E2 I: a; a3 ` set roads patches with
- p/ k! E6 U/ c) C7 a9 L/ e [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) [1 b7 o8 A) I4 E- P* y/ D7 S0 e5 Z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]. N; O) }9 e7 W' k' Q
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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