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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。9 b2 i5 U& \* z8 l' C
netlogo自带的social science--traffic grid这一例子当中,! v* s r7 @& ? U! `/ ^
globals( x% M1 M+ N) N) ~& G
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1 {: V& Y; m+ L' N grid-x-inc ;; the amount of patches in between two roads in the x direction
+ a" o1 ` i9 m* c# m2 B2 m grid-y-inc ;; the amount of patches in between two roads in the y direction, G) m, m4 x* @6 w# J' C
acceleration ;; the constant that controls how much a car speeds up or slows down by if
7 c" O/ {8 K( S1 W% V ;; it is to accelerate or decelerate
( M* _& c8 g( s1 h8 ]# J9 y. i phase ;; keeps track of the phase
, @; s# ?3 s! x1 L8 P& ~/ E num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure# O* v& v& m9 Z" e# `# P; l0 S) _
current-light ;; the currently selected light
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;; patch agentsets! l/ B, t. m z) V) Z6 K
intersections ;; agentset containing the patches that are intersections
8 V# W3 T# Z4 J0 m: Z roads ;; agentset containing the patches that are roads
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6 Q' S9 b' f d+ Q. Y0 S. eturtles-own
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speed ;; the speed of the turtle+ J7 K" d1 L9 R) f2 i
up-car? ;; true if the turtle moves downwards and false if it moves to the right) t3 W, q9 G5 `/ N& N6 |. E3 g' k
wait-time ;; the amount of time since the last time a turtle has moved
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7 [: _0 C% R; S9 epatches-own
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3 M, E8 J; V" u; F intersection? ;; true if the patch is at the intersection of two roads" A, P3 E' u$ h. B& l2 H: A
green-light-up? ;; true if the green light is above the intersection. otherwise, false.4 |+ O1 r1 Q6 p$ e: Q
;; false for a non-intersection patches.
9 n* o' B- ]/ Y" m: C7 V/ R. [' ] my-row ;; the row of the intersection counting from the upper left corner of the1 h3 J2 X% V+ D1 s. ~# a
;; world. -1 for non-intersection patches.
4 f1 A4 u- E" P* `1 c# v" [9 r my-column ;; the column of the intersection counting from the upper left corner of the( H5 i. g0 Y4 [! k2 B/ x# }! r5 _
;; world. -1 for non-intersection patches.! `1 }8 Y |/ m9 `8 w X& |
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
0 R9 a* T3 ~9 N auto? ;; whether or not this intersection will switch automatically.7 M- Z# E5 m$ H" Q+ y1 T
;; false for non-intersection patches.' }, W' t" ^. f' }( V% \, A$ W
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$ b9 B* ^+ y% Q O& c;;;;;;;;;;;;;;;;;;;;;;
3 x& h; i% T" L;; Setup Procedures ;;
8 R1 ~4 |3 [" p& U R;;;;;;;;;;;;;;;;;;;;;;
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1 x+ B: T& O/ X) O1 e. L1 F;; Initialize the display by giving the global and patch variables initial values.
; B5 }$ r: h2 y;; Create num-cars of turtles if there are enough road patches for one turtle to2 Z+ r8 a, q+ b& m J0 \, Z w0 A
;; be created per road patch. Set up the plots.0 j, ~8 }: T0 U/ U3 \
to setup
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9 q6 p( F. p: O- F5 c8 b: O) p" S; k4 m setup-globals
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;; First we ask the patches to draw themselves and set up a few variables2 T4 G8 I0 b7 B4 t
setup-patches
8 @6 K' F. m9 l( L3 T6 [# o5 ` make-current one-of intersections
" g# ?8 g& A G label-current
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set-default-shape turtles "car": _8 P- T# X# m
( _3 U( D& h, S: i- U' ^ if (num-cars > count roads), H; z. L( B P# ?* i7 r( V9 ^
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5 M. z# S1 M. o5 U" x. V user-message (word "There are too many cars for the amount of "% @4 h; X, d1 {5 I$ v4 N
"road. Either increase the amount of roads "
! e8 H% h" H" A" p. s "by increasing the GRID-SIZE-X or "
. A; v1 Q3 ]$ i `8 T5 M; ] "GRID-SIZE-Y sliders, or decrease the " k" Z( [8 X% w; K0 m6 u
"number of cars by lowering the NUMBER slider.\n"$ s" n* T( ~/ \2 c- V" A
"The setup has stopped."); ^7 c8 T9 M+ T& l8 i! a
stop, M7 a8 K+ M) y6 b, D
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9 L9 o7 E+ j9 q ~1 v+ p7 l8 k. C ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color Z% m0 H e# U
crt num-cars
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8 ?! h+ V0 Q3 C1 i1 o& C setup-cars
) d0 s5 L- n1 P- A+ l set-car-color
# ~3 W2 H( b' a record-data
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;; give the turtles an initial speed
4 k+ m5 H p# _ ask turtles [ set-car-speed ]
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3 L7 |- n( n, u: K1 y1 s C reset-ticks
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! Y6 @# M* I1 R;; Initialize the global variables to appropriate values
6 L1 z3 i3 |. W& b7 P/ y/ Rto setup-globals
. p8 n( |3 U7 @, a3 U$ o, u: ^# p3 g set current-light nobody ;; just for now, since there are no lights yet7 {; D% e; M% V8 C; J |9 j
set phase 0! O+ T8 e& U9 D) K2 K3 h
set num-cars-stopped 0
6 t' v5 Q. h% j% i, J0 i' O0 s set grid-x-inc world-width / grid-size-x- T2 f! z' v$ h
set grid-y-inc world-height / grid-size-y" I- h' p' [3 x2 O1 h7 ^
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary3 B# H; X2 [0 ]3 o# A
set acceleration 0.099# s6 K, |4 a9 N
end
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1 R) i# ]! {- X: {4 t! N;; Make the patches have appropriate colors, set up the roads and intersections agentsets,& \3 r; |; D4 Z" }
;; and initialize the traffic lights to one setting- J+ D# T) u4 t1 V
to setup-patches
: u! j& S! Z$ L6 m% A0 E ;; initialize the patch-owned variables and color the patches to a base-color# l4 `* ]3 [) ?: v: h! f+ R1 K
ask patches
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4 P+ m! P# s+ M8 @. i+ q' ^+ @ set intersection? false a! T% s _# R/ S7 D8 p
set auto? false) B& ^7 k. H' U; R
set green-light-up? true
/ z6 f2 B F. y set my-row -11 k. } P8 r; r& h
set my-column -12 ~6 L" w6 Q" b) Z- _6 A9 S
set my-phase -1/ x8 N- c, I' {: [) B2 ^$ H/ E
set pcolor brown + 3; e5 }. i+ p6 S
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; V- M+ J2 M3 u& n# ?: P4 O ;; initialize the global variables that hold patch agentsets5 o2 d' N( z) ^# p& ^& w
set roads patches with0 N7 b" M6 ^8 |* G
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ G; J' @' ]. k+ v# y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]( X, V: ]# U, A% }$ j4 {
set intersections roads with
0 E" k4 K: b# b1 b l2 z2 N [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and2 \" n6 X( P! w3 c
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ w5 t* C+ f; P8 F8 A
: [/ U: X3 Q3 P" Q% P ask roads [ set pcolor white ]
% \( @2 H* G4 W [0 y setup-intersections/ K! Y7 g8 L% P% |3 R; n
end s/ X4 q m0 O
其中定义道路的句子,如下所示,是什么意思啊?
/ |) ^! f3 B$ J5 h set roads patches with
7 ?& z+ C$ i3 O! d- W( | [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
3 v2 G; r- u% s. s& D (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; L' K+ i( v( l: o1 E
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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