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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。. A" x; _" |6 H% B! r& g
netlogo自带的social science--traffic grid这一例子当中,
. i7 r* c$ z& [% J" p0 \% j1 }9 jglobals! J4 m8 D: ]2 ^0 p
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grid-x-inc ;; the amount of patches in between two roads in the x direction
$ |' T: r' R F$ a/ i$ h grid-y-inc ;; the amount of patches in between two roads in the y direction: @3 }9 j& h5 t4 d& r8 T
acceleration ;; the constant that controls how much a car speeds up or slows down by if
4 B7 W4 I: D1 Y6 W8 K6 ]8 R ;; it is to accelerate or decelerate8 ?4 O2 R/ b$ H& M. d# F8 R
phase ;; keeps track of the phase
- c) x# F. p1 f9 G2 q- ~4 m9 B$ F num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure9 x1 Y/ T7 q+ L$ N8 I4 ]# i: h
current-light ;; the currently selected light
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;; patch agentsets/ B% X9 Z' E% N, X4 D; g4 p
intersections ;; agentset containing the patches that are intersections6 a( \% G' [ u L$ S% n; u
roads ;; agentset containing the patches that are roads
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7 ^9 ^( h0 ]1 f& I4 Wturtles-own
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speed ;; the speed of the turtle1 k& a5 s, K% B1 f
up-car? ;; true if the turtle moves downwards and false if it moves to the right
0 d# P; L& U4 T wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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( Q3 ~1 y% N+ Y. w intersection? ;; true if the patch is at the intersection of two roads
2 l8 G8 X* K7 L8 A green-light-up? ;; true if the green light is above the intersection. otherwise, false.
* u+ ~$ O( r* A0 s/ Z' q ;; false for a non-intersection patches.
/ Y+ X: V, @$ c8 s! x8 O7 `2 ~) t my-row ;; the row of the intersection counting from the upper left corner of the
" y' w/ c8 d! D, f* ^9 P4 @ ;; world. -1 for non-intersection patches.
( [/ t/ a. D0 H0 {8 q/ W9 C* F my-column ;; the column of the intersection counting from the upper left corner of the6 M* V6 G; V3 ?( Y: j& r
;; world. -1 for non-intersection patches.
6 K+ G S. I0 W% ^ my-phase ;; the phase for the intersection. -1 for non-intersection patches.' C7 V9 O/ l; q6 ]/ G/ x1 b
auto? ;; whether or not this intersection will switch automatically.
* L3 p2 C7 u( n* v& j2 p0 t ;; false for non-intersection patches.) j+ b$ f& U, V2 y, [8 P
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* S4 k1 K1 R' F0 } T;;;;;;;;;;;;;;;;;;;;;;
" C3 w3 U3 l( Q' w0 v- u) h& m5 O;; Setup Procedures ;;
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- h' Y3 a, F8 x1 u2 b;; Initialize the display by giving the global and patch variables initial values.) \4 f1 x# ]) \: S/ ?5 q* I
;; Create num-cars of turtles if there are enough road patches for one turtle to5 r! ]! ^( [% u! r$ Z) O8 h+ o
;; be created per road patch. Set up the plots.( n& H% @: G8 }1 {3 G
to setup
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setup-globals
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6 J" ~4 y' [' O ;; First we ask the patches to draw themselves and set up a few variables
: ?! ^* H2 x9 t: O setup-patches5 f1 @) w9 Y/ @( {
make-current one-of intersections
; l5 e7 S9 Q* f& j# t1 F: ` label-current
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4 a" M; A; r# w3 c; C U set-default-shape turtles "car"
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! X) W+ S* k8 o2 o if (num-cars > count roads). z- u% r6 v3 x4 Q# }: w: m
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user-message (word "There are too many cars for the amount of "8 ^ ]6 v3 |% \3 w' C6 K
"road. Either increase the amount of roads "* H. Y1 f# w i4 L$ A7 g, a9 L: A
"by increasing the GRID-SIZE-X or "8 C1 T3 l! i5 a* \! ?
"GRID-SIZE-Y sliders, or decrease the "
" S3 e( `0 A4 K0 ^; U- X# |% m "number of cars by lowering the NUMBER slider.\n"- A, ]* S( [" \- }% W
"The setup has stopped.")
0 O: W' b' w. K5 [% ^8 G stop. }+ ?* @! f* p. L* Q" z
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5 k1 R; t( i$ X( A4 V1 W, Y6 @ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
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setup-cars- w9 Q5 Z0 s# }! V; x) u
set-car-color
% F- t7 C8 H& k5 w6 s record-data; S9 D. h+ j9 O* V) l
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% l0 u& k) w" }/ X) c ;; give the turtles an initial speed- f, X' b/ J$ f: W2 L9 m( I/ E
ask turtles [ set-car-speed ]2 Z5 h! c2 q A9 N/ R1 C
) O& }8 X4 C8 J. k1 W: B6 w reset-ticks4 @2 M6 v6 J2 S8 _+ ]
end# N! j9 n$ e$ n& M! Q' v% t
$ x- s5 Z) w8 L# K% i6 i \6 z;; Initialize the global variables to appropriate values, q( W( s: O4 q+ s; D6 G: z
to setup-globals' _/ O' ` ~7 e! e2 |: n/ K$ u( A
set current-light nobody ;; just for now, since there are no lights yet
. }% N. P0 ^* T \- `, ^ set phase 0
6 Z5 r& @8 t( } set num-cars-stopped 0: S4 b# w1 r& e( `6 ]: J
set grid-x-inc world-width / grid-size-x) o% S3 U. g# m+ |8 v: k( u
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- ~% E6 K+ m- E3 t
set acceleration 0.099
, @' Y" r. G1 } Gend
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" v) o* P9 @- a8 D; _# U& y;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
5 A; e3 d5 | p;; and initialize the traffic lights to one setting
/ g$ D+ m/ }: s* C4 W: pto setup-patches
0 v6 A3 P- i" Z8 U5 J; k/ v4 v ;; initialize the patch-owned variables and color the patches to a base-color
7 E6 P0 h( n8 n% H% | ask patches6 ^( ^% Z$ _7 U s7 |) R) b7 h
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set intersection? false+ E% f4 j! T0 ^0 S: S( H k) D5 M% T
set auto? false5 N; T$ }9 U0 Y5 \- S! x
set green-light-up? true
- v- W2 }% Z' a& E3 p/ B set my-row -1
( v8 v( d8 T+ P# Z8 N- A0 l2 C set my-column -1
. r5 `( }/ x; u1 Y2 W set my-phase -17 I: A7 V+ w* P# D7 X: B/ G
set pcolor brown + 3, }- \1 z( l/ r, B5 z
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;; initialize the global variables that hold patch agentsets
. a+ {. [( h9 b1 I5 y set roads patches with
2 x, g1 `) x7 ?4 E [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
3 R" s, R* h1 A (floor((pycor + max-pycor) mod grid-y-inc) = 0)]' b7 q w/ |* V8 n
set intersections roads with
# S( h/ u6 _; y5 ]. w+ b [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
! Q$ U' F) u, j& p9 U (floor((pycor + max-pycor) mod grid-y-inc) = 0)] { a0 O1 ~1 s/ t
; S* F& L& N+ z6 H ask roads [ set pcolor white ]
! h" w8 M$ c+ R setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?" ~( c6 q( M6 Z9 B
set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]( M% J# E7 P" c. h3 W
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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