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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。( h' I4 u# g9 K% T6 h3 g
netlogo自带的social science--traffic grid这一例子当中,
q- g, u. l5 ?$ ^3 z/ o: _7 z% Gglobals
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5 A. A* z* e5 x {5 Q( W grid-x-inc ;; the amount of patches in between two roads in the x direction3 N1 K. v; }! T H9 V3 B
grid-y-inc ;; the amount of patches in between two roads in the y direction( i) S s0 @. Y6 V6 y
acceleration ;; the constant that controls how much a car speeds up or slows down by if
0 ]! _0 Q7 G0 W6 ^1 v ;; it is to accelerate or decelerate
$ I& w' Q/ t! E; j; n phase ;; keeps track of the phase
& J' g9 S; u( t. f L2 |' @8 o4 k num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure* a$ _- B0 U H: I) r- i
current-light ;; the currently selected light4 k: S0 B$ ~$ `1 C
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;; patch agentsets1 ~! U+ @( v9 M% e) d! ^
intersections ;; agentset containing the patches that are intersections/ n u0 a* B {$ h
roads ;; agentset containing the patches that are roads
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8 b" Q% @' f. V0 uturtles-own
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- t# J- L3 k2 H0 u- F- f speed ;; the speed of the turtle
U. O# C$ R& h3 f$ y up-car? ;; true if the turtle moves downwards and false if it moves to the right3 s! ]3 ~5 b; R x: V) L
wait-time ;; the amount of time since the last time a turtle has moved- E2 E3 u% R0 I, x; K
]
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patches-own6 T' j$ k8 z3 P5 c& B# P0 ^
[
" R: _! X1 \ ]: x5 R' ?6 U5 u7 L intersection? ;; true if the patch is at the intersection of two roads
: D- B& t: Z% e! ^6 B" H green-light-up? ;; true if the green light is above the intersection. otherwise, false.% Y0 f. G1 f/ S) R
;; false for a non-intersection patches.
/ D2 A1 y# i% Q( N' A: m! l& O" _3 d, t my-row ;; the row of the intersection counting from the upper left corner of the
- ~" V6 _7 i: P ;; world. -1 for non-intersection patches.
2 Q; q# Y( h5 X, x8 ] my-column ;; the column of the intersection counting from the upper left corner of the
; B4 Z/ |, J) |, d* v( T- a ;; world. -1 for non-intersection patches.4 Q6 g4 J8 v% U' F2 U
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
# X3 ~" p: x8 P5 k auto? ;; whether or not this intersection will switch automatically.
) z# E- }5 k& \0 Q ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
. p! k( Y, L4 q+ y6 G0 C6 W;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values./ o/ W9 P* r# c( R% i9 K
;; Create num-cars of turtles if there are enough road patches for one turtle to/ b4 R% g4 `, r- ]: I g9 f/ x e! a
;; be created per road patch. Set up the plots.1 ?# n, Q a G% F% Y7 n# t, N. S( J
to setup8 N/ `- g; n- B# T( D
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables) }. E2 B9 N, ]8 x4 r1 e5 ]
setup-patches
# E. o5 s$ Z# v- B make-current one-of intersections
/ j! K7 m- \' i5 Z label-current2 n( G" q W0 [' A- _/ e2 i
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set-default-shape turtles "car"
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$ M1 q) n, k% z+ X! Q* L if (num-cars > count roads); b6 T6 V m2 R' ~
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user-message (word "There are too many cars for the amount of "- c! z/ T5 V* B3 s. U; m
"road. Either increase the amount of roads "
# ?" ^ S, [; R1 C O "by increasing the GRID-SIZE-X or "2 d- A1 U& j4 x
"GRID-SIZE-Y sliders, or decrease the "
- F0 M* C& C+ f0 H6 j "number of cars by lowering the NUMBER slider.\n"
. o! z, D5 V3 n# F% R, | "The setup has stopped.")/ b, s( i: {( ?% T) E
stop
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" Q! d- ^2 x3 k7 ?- Q" w ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color; @+ _+ w3 l3 e* F5 A9 u V
crt num-cars
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# M# j4 ^3 L# y7 i% C' b setup-cars
! m0 D. u8 i# U* m& v; t+ h set-car-color% D2 B( x/ U' d6 i/ b9 r
record-data
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4 P0 D7 Q& F* f1 w: l, Q ;; give the turtles an initial speed/ F1 L8 r2 L$ A
ask turtles [ set-car-speed ], C- N: a7 _( r! v2 F" ~: f& h
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reset-ticks
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Y1 }1 I6 l& Y& {1 K;; Initialize the global variables to appropriate values2 _+ a9 B7 t$ V! }8 ^7 `. s" Z
to setup-globals8 _( a% H. A8 o9 O. n' d5 Z
set current-light nobody ;; just for now, since there are no lights yet! r1 _' { K$ @- p) ?
set phase 0
+ [* f* U2 c! K6 y set num-cars-stopped 0
( u& S3 \; t0 z) C: L) \7 a. a; ?# d! K set grid-x-inc world-width / grid-size-x
& D% p% \+ a& }5 l( c! 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% p2 H! h- B/ i, M/ p- B# ~
set acceleration 0.099; S$ s! e7 M+ L6 [
end
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~. Z5 L, G" r7 B. t;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
. T% f" g# e! G# G, I;; and initialize the traffic lights to one setting
* L$ j+ o; P9 S9 hto setup-patches
, k& m1 q, n7 C! d ;; initialize the patch-owned variables and color the patches to a base-color" v* N, y$ S$ T6 V8 r8 s' L2 q9 S
ask patches
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set intersection? false
3 R2 S3 J0 M: w z' u! y2 U4 u set auto? false* Z: I1 X& F4 u5 S& n# C+ l& ?; ]
set green-light-up? true
2 T; M! ?2 j3 a8 _" Y% f set my-row -1
7 R; u' w: s; l4 K0 b7 S set my-column -1
; K" t: @* z" i* _ m set my-phase -1" l$ `9 A }' s& d# E. g
set pcolor brown + 39 Z0 z) N, j' P. I- n3 L" [
]
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;; initialize the global variables that hold patch agentsets6 a( i# x9 T4 K
set roads patches with
9 ]$ z, V4 `2 q" U. F [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 x( N- ?1 |& p9 d4 q+ w (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 f* E; ^/ ?: c$ f+ M' |
set intersections roads with
: G+ n) ~1 {# U [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and& k) q' B# b8 q; A) {: A, i4 ?2 I
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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* D7 S# F7 {2 E+ {! w% B ask roads [ set pcolor white ]
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end! ~7 ?3 r3 l5 j( Q. L% f
其中定义道路的句子,如下所示,是什么意思啊?- F) v+ p" ]! `0 k* |5 x. ~
set roads patches with
" T! F) B) }& B, n& r$ t [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! r) C) l. R/ F7 } (floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 R" _ @) [6 J
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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