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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。
* o. w8 V5 W9 Unetlogo自带的social science--traffic grid这一例子当中,
7 o3 k2 b- \% N* V! F: T; G Zglobals
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9 u2 f, K* u+ o0 P6 `9 ^; l" k grid-x-inc ;; the amount of patches in between two roads in the x direction
) }: E& V" O4 q6 V3 }3 V grid-y-inc ;; the amount of patches in between two roads in the y direction1 D/ C5 _: t' e
acceleration ;; the constant that controls how much a car speeds up or slows down by if6 x; f/ G+ j( K; J$ n) o
;; it is to accelerate or decelerate
! i% O; `/ t7 b2 d7 K& q phase ;; keeps track of the phase
! r/ P3 V6 J, T" C num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
5 P+ B# M9 v- R w" x0 t current-light ;; the currently selected light
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;; patch agentsets" A' }/ J4 L( L' a. N
intersections ;; agentset containing the patches that are intersections- }& ^/ V+ m" Q# v! f! \0 N
roads ;; agentset containing the patches that are roads3 f. Z& l' b6 }1 H# v7 j, t
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$ H/ \; f/ a# Eturtles-own
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speed ;; the speed of the turtle; ]+ Y6 g D3 R8 ^; E7 K
up-car? ;; true if the turtle moves downwards and false if it moves to the right
9 W' x) M, `% l+ w' e* I wait-time ;; the amount of time since the last time a turtle has moved
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patches-own8 c7 Q3 }, M c: W$ l6 n
[
8 O+ ^8 K2 ~5 w intersection? ;; true if the patch is at the intersection of two roads
6 z1 Z( X9 `% E" d, ]1 E- \ green-light-up? ;; true if the green light is above the intersection. otherwise, false.
9 i+ R0 r% ^' {, s ;; false for a non-intersection patches.# Y$ f1 S1 V* k M! E$ m8 Q! G% t
my-row ;; the row of the intersection counting from the upper left corner of the
' v6 E! Z! k1 K* `( i ;; world. -1 for non-intersection patches.
0 O4 V: {$ W' h) o my-column ;; the column of the intersection counting from the upper left corner of the
! A! _! e# q# `1 }" m9 ]0 ^$ K ;; world. -1 for non-intersection patches.
! n+ b* k) i2 `( ? my-phase ;; the phase for the intersection. -1 for non-intersection patches.
" L) [ d6 _: G! n auto? ;; whether or not this intersection will switch automatically.
% R8 J+ ~, I x, L8 ?" @& E ;; false for non-intersection patches.3 V8 P7 E4 q( ?
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;;;;;;;;;;;;;;;;;;;;;; u* H+ s! `) V' e. W+ B
;; Setup Procedures ;;7 Q/ m l' {! E# E1 a; k! F: g
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
5 G) a! w4 ]$ ?) f( r1 j;; Create num-cars of turtles if there are enough road patches for one turtle to
& u i0 g7 E" a8 A G3 D8 V;; be created per road patch. Set up the plots.
7 c! i' G! x9 j: ~; x, f# qto setup
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, r5 }4 [9 q5 Z9 h! ~# \% r5 C setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
0 z& M" I$ U, j setup-patches9 D" ]( W. y/ b1 d' o% M
make-current one-of intersections' s6 U" Q7 A; _6 o6 D
label-current$ n$ q) v/ w. x: u3 y$ {" P/ D
0 U- l' ~& E" h4 f4 h" s$ q set-default-shape turtles "car") o$ b6 |" J7 z4 w
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if (num-cars > count roads) r5 W. l9 H* R* t3 o
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user-message (word "There are too many cars for the amount of "
3 {7 b9 e0 n: Y" i3 C& { "road. Either increase the amount of roads "
: ?2 v" i9 T5 p- b3 Q, R/ R "by increasing the GRID-SIZE-X or "
9 Y" v" A- p) L "GRID-SIZE-Y sliders, or decrease the "& f! @: O5 }9 l! y# S
"number of cars by lowering the NUMBER slider.\n"
2 q2 ]# F; U4 R2 a1 T "The setup has stopped.")
, q: ]& o' `) R" L( A; K stop. s6 e4 c; |5 z9 I4 C6 i
]
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
5 z& U. q: j" _$ y1 f) Y, t crt num-cars; p% T3 y/ a- Z! i) @, y+ n! g
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setup-cars. G* z* ]. R7 V4 S
set-car-color0 ?% O5 I; }7 k) A
record-data: a1 \4 e" [- M" T! D% k: e
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) x+ P# U- }- t( F* L ;; give the turtles an initial speed% [7 K4 ^) t/ g! _6 n
ask turtles [ set-car-speed ]
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reset-ticks# ]$ K$ I% y) C/ H, C/ h
end" `6 u( E. ?$ M
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet/ [5 c- ~1 Z7 R+ {+ f7 v3 I: x
set phase 0; I% R# v3 J6 v X- U+ z
set num-cars-stopped 03 J4 @! b' u& A% j! n' `7 H
set grid-x-inc world-width / grid-size-x
" s% Q( Y w* X* R+ o2 ~& k9 i% \# p 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% S8 C! r; b- m7 y; u4 B& V) ?
set acceleration 0.099
" I! }) h/ u! u; Z# q7 |5 |end& v& A* `# J) P/ p# s) N1 V
' d4 R! p- Z* R9 F3 c;; Make the patches have appropriate colors, set up the roads and intersections agentsets,( e! a+ b$ ]9 V# L2 c5 V
;; and initialize the traffic lights to one setting
1 Q, |' f: D% K* V# Lto setup-patches- i' x; e# P; k' U, \
;; initialize the patch-owned variables and color the patches to a base-color( t9 a4 M( c8 W" J0 p4 _+ T. F
ask patches
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& X2 e% K0 U% ]0 P: @ ] set intersection? false, D. h1 a- c* g% K. `' |
set auto? false: Z3 a7 v3 h" Z" D, n/ @/ J
set green-light-up? true2 ]& ?, {! r, B
set my-row -1
& {& _) N2 N5 E set my-column -1
0 z7 {0 B% M2 ?4 e set my-phase -1& r$ {( x( ?9 `- J n# ^
set pcolor brown + 3
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' _ ]+ N+ ?# t ;; initialize the global variables that hold patch agentsets2 `6 ^; h6 u# x: B8 o3 Z& T
set roads patches with
% U! L2 [! V& ?# d; P: w [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ Q# |6 U3 W* b3 M* ~4 ]4 N# B (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
! P0 Y) D* E# F7 p0 I$ t# M set intersections roads with- C y2 [. R8 T
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
( G. z" K' N( l7 r) v3 H: ^) V% c; Z" M (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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- u/ E$ _3 J3 }, L2 W8 T ask roads [ set pcolor white ]) n" F" |& x/ y& w4 S& u0 v& e
setup-intersections
2 G, Z/ a0 F; aend$ A* }9 C1 i2 x) @) f
其中定义道路的句子,如下所示,是什么意思啊?
. u- b8 A# k# u% O! n( H4 U set roads patches with7 {' k* ]3 `( A( a8 Y
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or0 h2 f, ]% i% E7 d# o+ E
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. J0 x$ Y$ X5 G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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