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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。
0 b9 M4 v, W8 d0 r! qnetlogo自带的social science--traffic grid这一例子当中,
) }5 A Q- G C/ b! s" Vglobals I: T0 p+ H9 a
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grid-x-inc ;; the amount of patches in between two roads in the x direction& i& W# `8 q& h d) g( c y
grid-y-inc ;; the amount of patches in between two roads in the y direction
# q6 f6 r; |5 i: C3 M, E acceleration ;; the constant that controls how much a car speeds up or slows down by if1 {" @7 }& b7 D
;; it is to accelerate or decelerate0 u, ~% @0 A4 C5 X
phase ;; keeps track of the phase! ^ W4 j( Q8 G
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure! B$ o' v4 L% A! L5 G( Q
current-light ;; the currently selected light
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- y" P0 w3 k+ U6 F# d9 o$ v ;; patch agentsets: q2 o. Z. Y' G' g8 k
intersections ;; agentset containing the patches that are intersections8 C% X- }# x5 | d, {
roads ;; agentset containing the patches that are roads4 E( X4 b1 J1 P* }
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turtles-own& s; \3 d1 U, Y
[
: `2 }5 z* p' r( G1 {5 @# q speed ;; the speed of the turtle; o. s5 ?0 F: z, \% P5 F* m* d8 }
up-car? ;; true if the turtle moves downwards and false if it moves to the right n2 P/ e* `7 ~1 [* Y# ^
wait-time ;; the amount of time since the last time a turtle has moved0 {' m) X. F+ E4 P& E' |
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patches-own/ n1 {: E$ c+ _% Z, ~( e
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intersection? ;; true if the patch is at the intersection of two roads
" N8 l5 z' @2 V! M4 h green-light-up? ;; true if the green light is above the intersection. otherwise, false.
" O. T. X$ W8 ~( P, S2 b: x ;; false for a non-intersection patches.0 x4 q% i8 ~" t# {3 e8 A, H! N/ |
my-row ;; the row of the intersection counting from the upper left corner of the
2 {* b+ B8 u6 F; i" M$ K ;; world. -1 for non-intersection patches.% g ?$ f) ^6 y, Z0 b
my-column ;; the column of the intersection counting from the upper left corner of the
+ N! h' }/ i. I1 q# @; T% i; f ;; world. -1 for non-intersection patches.4 m9 _. w' K* X- k. ^- \ y
my-phase ;; the phase for the intersection. -1 for non-intersection patches. ?5 y2 h+ h8 G1 z
auto? ;; whether or not this intersection will switch automatically.
/ q) F. W2 `0 l% q. r/ U ;; false for non-intersection patches.
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; ^2 B) U$ c' r: O7 y;;;;;;;;;;;;;;;;;;;;;;+ x& `' Q! U4 z; \( B( w7 {# P4 G7 f
;; Setup Procedures ;;
! S. y# Z2 |" J2 J) f2 I;;;;;;;;;;;;;;;;;;;;;;
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4 z2 D2 t9 m; X;; Initialize the display by giving the global and patch variables initial values.' M" X5 h8 [. E4 T
;; Create num-cars of turtles if there are enough road patches for one turtle to: [0 |+ H; N( U
;; be created per road patch. Set up the plots.2 _2 n6 O) O4 c2 o1 z
to setup( O# r$ I" h9 j; r8 ?+ G0 R
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setup-globals: u7 e/ r( D6 @
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;; First we ask the patches to draw themselves and set up a few variables
2 k/ o9 R- ^& r, M5 n+ f/ }' G! R setup-patches
3 g# a+ Z$ {: Y2 T+ h, l make-current one-of intersections
$ t. E; W1 ~3 ?! J label-current
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set-default-shape turtles "car"
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5 W) l1 \' D) M: M; x8 u if (num-cars > count roads)/ E6 U, P6 x; X4 _8 i; D6 f3 G
[
6 {. K# O" A* V5 T x user-message (word "There are too many cars for the amount of "$ o0 p& \, l7 L- f
"road. Either increase the amount of roads "- o' X9 U/ m8 d! {4 s
"by increasing the GRID-SIZE-X or "& H% O2 w( |! }$ C- C
"GRID-SIZE-Y sliders, or decrease the "# V, p" `% l% W9 {; b4 }
"number of cars by lowering the NUMBER slider.\n"/ e* A' M; ?9 e
"The setup has stopped.")
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: t* Z/ \. X z* J( m; j. V, ]# W ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
* _2 [: q$ ^0 H$ @9 G crt num-cars
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setup-cars
5 Q0 ~+ i% J; k) ^7 ~- Q& x set-car-color
! @# W1 t. |% @8 F5 A8 b8 {5 k record-data
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8 s: l# d0 d. C) p) } ;; give the turtles an initial speed: t( f: K. d( v/ g% J& |" \
ask turtles [ set-car-speed ]
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reset-ticks9 N& @! ]% y# h+ W1 `8 ~1 ^1 V; d! H
end
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;; Initialize the global variables to appropriate values, u+ K9 H5 @& X$ e
to setup-globals
% Z5 p8 R0 D% c3 Z set current-light nobody ;; just for now, since there are no lights yet% H3 U! _, S$ m- c& z
set phase 07 u, V( r1 L3 L ?1 }9 y ?4 s5 A
set num-cars-stopped 0
6 g; U7 |5 C: ~8 n# W7 P% f2 q set grid-x-inc world-width / grid-size-x0 S5 s* ^& `4 W' c6 j
set grid-y-inc world-height / grid-size-y3 R8 ], j- s" L; [$ o Z: u
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary/ l v$ O- l+ K& R3 m0 i
set acceleration 0.099+ s9 y: e, H# g1 N* `
end9 n: F. |: h; @
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
& @, L8 I2 {4 m: a3 a6 ];; and initialize the traffic lights to one setting* ?+ @9 g, b9 Z6 k: _1 p
to setup-patches
9 M. h: e3 ~* W ;; initialize the patch-owned variables and color the patches to a base-color
9 ^/ T6 c& d2 D9 N8 _ ask patches, ~ X6 p# B4 K
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% D- M9 F2 f1 h1 `3 N/ [) F3 q set intersection? false
4 P {/ V% r; h! {( e set auto? false- @) i* j, m# [* I
set green-light-up? true1 B1 [, B2 e- ?/ [6 D1 R( ^' W
set my-row -1
/ v) `5 d2 \, }3 m& X! w set my-column -1
! @5 L6 C. F- m set my-phase -1
; _% r6 V9 h4 {7 C set pcolor brown + 3" N8 _ D3 j( H+ {3 ~
]
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;; initialize the global variables that hold patch agentsets. z C; f4 F% j! L/ a1 |8 m
set roads patches with
0 O' P+ m! I* [ b+ a& K [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or3 O* N6 |- e7 h
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ c N9 [! q# z- M. } set intersections roads with
$ T8 R/ K# {' d' w [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and7 q) n4 r, }! a$ |8 `8 J+ i- Z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ P& V# L/ \& Y9 p2 N4 s1 i
2 n$ J. d1 l) [8 a( Q G% P/ |1 v9 r ask roads [ set pcolor white ]
5 m3 q" p+ r i1 `9 `1 M3 P setup-intersections8 r, N2 ]* n6 ]# f( D$ P) ~; m
end8 S6 m5 J3 x6 A) z% l3 B- T( N7 r
其中定义道路的句子,如下所示,是什么意思啊?
- |1 z2 z4 N' f set roads patches with
# \# l; r$ x" E# g8 K [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or/ l& f: S1 z$ t* V8 V3 D9 T
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]- C8 |/ S& f- z& Y" J$ U" 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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