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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。
8 x- F2 V5 h( Q7 b( D# a) Vnetlogo自带的social science--traffic grid这一例子当中,2 e9 o7 }- K, G: n7 M
globals
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# V+ b f. i5 M3 U; t5 Q; | grid-x-inc ;; the amount of patches in between two roads in the x direction
4 ~+ T; f. M( E grid-y-inc ;; the amount of patches in between two roads in the y direction9 b( p2 k' H+ e' a3 ~ }5 s6 i
acceleration ;; the constant that controls how much a car speeds up or slows down by if
1 k) I; }* i$ [7 s0 p8 @ ;; it is to accelerate or decelerate
$ k( l' g, g4 W) f s# _ phase ;; keeps track of the phase
2 D3 X% v5 \9 R8 v num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
( U. Y! \! @' \7 e! t current-light ;; the currently selected light6 _/ S; Q+ f$ n/ q, s" j* Y& f% h
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;; patch agentsets) H8 O& C1 H2 o. e2 l2 Q+ d
intersections ;; agentset containing the patches that are intersections* l6 M3 s3 o) @1 Z" v
roads ;; agentset containing the patches that are roads% U' J. C0 K& d
]
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turtles-own- H d+ y" C( {; f
[
) g, H- S i. k' l" a1 O; Q speed ;; the speed of the turtle- f+ \) I: w0 P9 E
up-car? ;; true if the turtle moves downwards and false if it moves to the right
, a9 X$ c: R* z- R wait-time ;; the amount of time since the last time a turtle has moved2 a7 v' O3 [5 R8 c3 p N5 x/ I4 t
]
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; X5 Y2 E. u/ y C) ]. ~patches-own( k7 T5 {: u3 M# ~& U& m" q: q
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! A5 b8 w/ K$ \7 R intersection? ;; true if the patch is at the intersection of two roads
3 {' V2 f& n7 F& [/ i6 T2 j green-light-up? ;; true if the green light is above the intersection. otherwise, false.
: j2 D4 V+ J& L1 j ;; false for a non-intersection patches.5 S, B. I8 e% Y; n# v2 G9 l+ m
my-row ;; the row of the intersection counting from the upper left corner of the
5 C* R+ Z7 S! c+ \" h) A) ]+ i ;; world. -1 for non-intersection patches.. v/ U1 ?. L/ m; c# w2 e6 u& w
my-column ;; the column of the intersection counting from the upper left corner of the
6 y2 N- b1 _, Q' d ;; world. -1 for non-intersection patches.
- g5 A" x2 k+ i# h8 }' I# d my-phase ;; the phase for the intersection. -1 for non-intersection patches.
" L+ T- ]) p J3 [ auto? ;; whether or not this intersection will switch automatically.
3 N; t8 b3 D. j5 L0 h* K; f% T( D ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;: Q* I" f5 {+ i7 d1 f& J
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
, D% f$ r& r5 J, z- \. L( B" u;; Create num-cars of turtles if there are enough road patches for one turtle to1 D% T2 e3 b/ Q7 D/ O* v
;; be created per road patch. Set up the plots.5 `) `2 \- h9 N' y
to setup& p/ Z5 q2 }2 \" J
ca
' b" b* M) K9 q' \: @- A setup-globals
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;; First we ask the patches to draw themselves and set up a few variables+ B1 U5 }% U7 y. T! q& B
setup-patches7 c; T5 P; K% @7 G a
make-current one-of intersections
1 V0 c% V' }% G, E label-current I9 [9 R2 m6 _6 f; I' x- e4 e6 Q
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set-default-shape turtles "car"$ p+ E. Z; H+ ~7 x
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if (num-cars > count roads)
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/ d% r8 b3 z7 y; N5 d1 B user-message (word "There are too many cars for the amount of "3 j( Z8 Y0 w% c. V6 g5 P3 x# t
"road. Either increase the amount of roads "
' [% R5 L2 K1 ` "by increasing the GRID-SIZE-X or "
- X9 q# ?; ^: ?: t' k I2 O "GRID-SIZE-Y sliders, or decrease the "
" G4 t" d1 E4 v/ P6 m3 g; L "number of cars by lowering the NUMBER slider.\n"" Q3 y. T* T" ]. u! [) J1 }3 w
"The setup has stopped.")
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color% Z0 {; Z+ c* w0 G% r4 y7 `4 W
crt num-cars
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2 L0 o' Z, ~, M% ]7 B- h# C setup-cars1 ~6 [( L7 B' |# f, G; J# B, v! ^
set-car-color
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;; give the turtles an initial speed8 d7 T* d3 n8 W$ J* X4 \
ask turtles [ set-car-speed ]/ ^# r* r7 i1 }$ d) M5 I
7 t. x5 T2 e9 f; S1 z reset-ticks* N7 J+ n5 U& C8 E- r& B- ~& z& y
end
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5 O+ X r. q+ t" j! z+ F;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet, s( w- [1 C# Z7 W7 m5 k1 o
set phase 09 j1 K4 r- c( x0 j( c4 `. t4 P
set num-cars-stopped 0' n0 }- i9 D ?" G( U( z4 e
set grid-x-inc world-width / grid-size-x5 \) N: L4 O5 f! W/ V W
set grid-y-inc world-height / grid-size-y
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2 Y( i4 t) [2 D2 q3 N ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
) z% Q k4 [% t9 `+ b6 R$ o! ] set acceleration 0.099* G* z1 C' l2 K
end1 L. m5 m! ?& V; O4 m/ }
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,. M/ l" [( x; h" a8 y& f* g' z0 C I
;; and initialize the traffic lights to one setting; c3 d" _$ c9 |; G- ^
to setup-patches
! _; I# t7 {& g/ `" i: g# ~ ;; initialize the patch-owned variables and color the patches to a base-color
7 g$ } r. I/ n ask patches
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set intersection? false4 `" E/ v7 z9 _1 Y! E: g: @
set auto? false. \: `4 m$ c0 b( R
set green-light-up? true2 y1 k g. T k1 G4 ?# i, O3 E
set my-row -1
- i. e3 ?. t- S2 l5 Q* I1 d set my-column -1
" [, o' N3 u( M0 b7 l# t6 A* E5 v" j set my-phase -1
: [% z6 B3 ~, j! ]: b) O! M S1 f set pcolor brown + 3
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+ ~( R4 l& f+ L5 [2 i2 |6 B ;; initialize the global variables that hold patch agentsets! h# \. P; t8 D/ C
set roads patches with; q% P" Y, w" s& P8 p7 G
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: l2 A3 M* {% x: I (floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 ^$ r2 B9 H8 w8 _
set intersections roads with) ]' |# F ], y' _4 |
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and: O2 b# K7 P, |% S0 U$ Z. C9 g
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ }. b3 g/ K& {6 ]
! h6 {3 p- l( C V0 P7 j ask roads [ set pcolor white ]! L, V# V$ X% l6 ^$ b8 ]
setup-intersections8 D: K* }7 H( S, a6 D$ U0 F' g
end
' h( r8 |. S1 O# {其中定义道路的句子,如下所示,是什么意思啊?
& f3 _# i: I% c) m: } set roads patches with
# R; x, u) M4 S3 j- r/ a [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' \0 G; I$ R$ a9 B (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 V9 X& |7 h8 c4 T- h, G) a$ h( Z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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