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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 g% e* a; L* R% {; G- y, a# h! Fnetlogo自带的social science--traffic grid这一例子当中,
: b) ^) r3 o& O4 f8 j gglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
* \' W- \9 z. j/ f: a7 T- o grid-y-inc ;; the amount of patches in between two roads in the y direction
. j' r/ e6 \; m( f acceleration ;; the constant that controls how much a car speeds up or slows down by if) i' D. q7 N9 Y5 |9 @* E0 Z0 F
;; it is to accelerate or decelerate
. \& ~; ~( }/ X( t" a phase ;; keeps track of the phase
. y C& ^: n* x1 w0 I8 Y7 o$ o+ w6 G4 i num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure: U+ n' I& d0 k' A% y" i
current-light ;; the currently selected light
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;; patch agentsets. `1 G& v h5 e- f
intersections ;; agentset containing the patches that are intersections
1 A( v4 t9 {/ R* l' o" b" ]6 A roads ;; agentset containing the patches that are roads% l& R/ z2 l! [+ A0 @; Y2 N5 V
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- z7 ]! q4 Z' n: f1 n+ o h& L! yturtles-own
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5 ?6 t0 x6 ]0 s5 F$ {. i: q. V speed ;; the speed of the turtle# W7 C2 n2 B6 V7 e0 t& r
up-car? ;; true if the turtle moves downwards and false if it moves to the right h- H0 g% j1 ]* u$ o# d2 c/ f
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
) T( {" F6 A* b) f" m green-light-up? ;; true if the green light is above the intersection. otherwise, false.& a0 R6 X5 V* M3 _+ x% s( M! x ]
;; false for a non-intersection patches.# `. a3 P" A/ x
my-row ;; the row of the intersection counting from the upper left corner of the% o: I/ c3 @ W# l8 g; Y5 X9 I1 c) y& n
;; world. -1 for non-intersection patches.
8 l3 j5 q6 ]$ i9 X% a& { my-column ;; the column of the intersection counting from the upper left corner of the, y7 [/ b4 w* j$ |3 T9 G+ Z; f
;; world. -1 for non-intersection patches.. G# F8 n' M3 L' c
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
% U* C, X! A2 u: { auto? ;; whether or not this intersection will switch automatically.
/ j" \4 R1 K; j6 f5 v% s0 Q& h ;; false for non-intersection patches.& X$ ~) \2 d/ I1 _6 n7 W7 k. ^
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;;;;;;;;;;;;;;;;;;;;;;
# y: |6 n! M" x: v7 j;; Setup Procedures ;;- M" A! a; ]. Q: U5 h t7 g$ [" W
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;; Initialize the display by giving the global and patch variables initial values.$ b0 d6 p! [( v+ _4 \7 x4 s/ J
;; Create num-cars of turtles if there are enough road patches for one turtle to
( j% w }; b4 |5 o1 J3 c, g2 W; x;; be created per road patch. Set up the plots.
; E% c; ]& S% Yto setup
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! Y: p$ I* X0 N, c: P setup-globals% b9 y: k. |2 B
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;; First we ask the patches to draw themselves and set up a few variables6 J8 @' u4 c, \
setup-patches2 M6 j, s$ r4 @; ^
make-current one-of intersections
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set-default-shape turtles "car"
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+ b" @! a z) ?. u7 u' e; v if (num-cars > count roads)! f: v k" }2 L: \: }+ a% L; d
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2 L8 r' I2 B9 b# J9 A user-message (word "There are too many cars for the amount of "9 J/ ]" r5 w. E* w5 X0 q9 y- T; \% F
"road. Either increase the amount of roads "9 E( U4 k- K: Y
"by increasing the GRID-SIZE-X or "
% D% ], c* r2 J6 J' W! x "GRID-SIZE-Y sliders, or decrease the "8 ]* {3 f) J$ R9 h! _: l1 D
"number of cars by lowering the NUMBER slider.\n"$ c* e* e' |! H5 y2 H2 k
"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) d# w% ?/ U F7 k) R
crt num-cars
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& b& T2 }# @0 z1 v setup-cars$ b/ Z3 R$ k' H- m9 D
set-car-color8 T s' c% ~! g. e5 ?8 a4 p7 D8 I
record-data- z% o) k' {5 M7 Z; {. {* [$ N* Z% L
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$ K: m* p7 v, Y" M ;; give the turtles an initial speed; h; o. l8 c$ K4 O0 k/ m) z
ask turtles [ set-car-speed ]" u) R& D# f# s
: c5 ]9 L! {: B0 U$ J C6 X reset-ticks, D. k2 C: O" s8 G
end
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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* k4 ^2 `; w8 ^$ _/ D. U
set phase 0
/ V" Z2 O9 b( Y. h' v1 ~ set num-cars-stopped 0
- w' Q& y. s1 f+ E& U+ u2 \# v( H set grid-x-inc world-width / grid-size-x
$ O+ R# k5 C6 |% \ 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% i& L% ~5 y6 y8 b8 @4 n4 ~ K+ T8 y
set acceleration 0.099 _. P3 \- F( c+ F& [3 o- b% h
end' z" K H: _7 n1 t
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
: K4 f A$ A8 B$ v, M;; and initialize the traffic lights to one setting, K& e4 ?* Y! x b/ n) p
to setup-patches
0 ]. Y2 U' T2 G! Y* i+ L8 q ;; initialize the patch-owned variables and color the patches to a base-color4 q6 K3 Q! `8 J# {: j3 s
ask patches
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: [4 W$ d1 P! n8 Z a4 Y! G3 B+ ~" O set intersection? false
' L! @# W3 P( h, m9 E2 T1 N6 ~ set auto? false( [$ m7 C3 K7 k. e: T o% _
set green-light-up? true
# d7 i8 C+ c1 E* H set my-row -1+ [0 k! g& Y3 s M$ j, u( ~
set my-column -1
$ l7 R9 N$ z. C; u7 W3 j0 F/ u set my-phase -1
/ A) s" i9 w( u& o, I U6 g4 V set pcolor brown + 3! ?* n" O; d, Z- o; V
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;; initialize the global variables that hold patch agentsets6 d! u, C, x& {8 Y- u
set roads patches with: Y8 x* F" \6 m+ {" w4 d
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! H( {* b9 a$ O* ~3 A% l" I
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]" `+ N6 B( B c9 [8 u( c# f1 \4 j
set intersections roads with% j: ^2 f0 p9 h" u5 ?5 E
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
; x3 p9 c' i/ [, c% d8 |: U (floor((pycor + max-pycor) mod grid-y-inc) = 0)]% N8 O8 J/ k& [: H: V5 x3 y. I
3 _1 ^* W& w5 P- V/ h: N ask roads [ set pcolor white ]0 s; z0 J' u8 G- o6 P, t
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?
6 t5 m9 c/ u6 L* | x set roads patches with% T) h+ n+ r7 ]* ^- k* {: }& H2 K
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: G' E( O( N' j( A2 C7 I3 ] (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, ^' S+ X* q7 |) _6 U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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