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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。
' g8 a b y! y! C5 `! Inetlogo自带的social science--traffic grid这一例子当中,
) u* l6 i" G7 {2 D2 Iglobals
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( U7 ~$ A/ g; v' K7 p grid-x-inc ;; the amount of patches in between two roads in the x direction
/ H3 j2 P3 t! ^ grid-y-inc ;; the amount of patches in between two roads in the y direction
/ k/ A0 Q" u% s" I+ L9 p acceleration ;; the constant that controls how much a car speeds up or slows down by if
" G) k# w% H- A5 L! h3 {6 O r5 A ;; it is to accelerate or decelerate
1 o; C5 t9 ]9 I) b0 n8 o2 F phase ;; keeps track of the phase' S G' U6 Y# i! f1 [. ~
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure& Y0 \) {& F7 w) c* g" v f2 p
current-light ;; the currently selected light
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" {8 G. Z x$ V, g p) D& }5 a ;; patch agentsets9 V# H" J! k* u/ Q0 c
intersections ;; agentset containing the patches that are intersections
8 {, f+ m* H" A- U1 f! o. G, u roads ;; agentset containing the patches that are roads6 p& G o: @5 p$ _6 P9 B
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& Y6 }/ N6 x' D: bturtles-own
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speed ;; the speed of the turtle
* J/ C. R, r/ L! }) e" H up-car? ;; true if the turtle moves downwards and false if it moves to the right# g8 A$ u$ R' S, d/ p. e0 e
wait-time ;; the amount of time since the last time a turtle has moved" T. b9 r4 {/ I$ ?
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patches-own
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4 M! C8 V7 ~) o* i intersection? ;; true if the patch is at the intersection of two roads
7 n# `5 I# L; O- ^( w/ }+ Y( [ green-light-up? ;; true if the green light is above the intersection. otherwise, false.
/ u) k# }. Y# G. v ;; false for a non-intersection patches.8 D7 O: @# `% ^: m
my-row ;; the row of the intersection counting from the upper left corner of the
& ~6 |$ p" U8 I1 f0 f7 {) y' h) S ;; world. -1 for non-intersection patches.
6 s5 r3 Y9 m9 O. y my-column ;; the column of the intersection counting from the upper left corner of the+ Q6 D3 R9 C4 }) f8 f0 T8 p
;; world. -1 for non-intersection patches.' S; h. R/ z7 g0 M$ Q+ {
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
; a J7 d! _9 s$ { ?/ u auto? ;; whether or not this intersection will switch automatically.. w3 V `/ n* D. q: Q- |' O
;; false for non-intersection patches.: Z& m# S7 G6 l6 }1 n. {! T5 k4 b
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;;;;;;;;;;;;;;;;;;;;;;. ~' L- h6 p- g% w3 Y1 {
;; Setup Procedures ;;
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' z8 ^9 ]) h2 z# J+ s;; Initialize the display by giving the global and patch variables initial values. p' h& n- H$ {
;; Create num-cars of turtles if there are enough road patches for one turtle to
w! H7 ~5 M/ u;; be created per road patch. Set up the plots.
0 g& |. }) z6 {! ^to setup2 c9 x3 p) \5 j* B, ~' H
ca
: m+ l5 J" m* z6 V) E/ j setup-globals" K# o: X7 R! ]7 e+ q7 |: h' I( {
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;; First we ask the patches to draw themselves and set up a few variables- ?; u4 }4 D. e* `& B1 {6 L. p
setup-patches
) b! f' E7 N9 t5 k5 ?4 ]/ d7 i" G5 b make-current one-of intersections0 G/ |# q* ~6 o& b* K
label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "4 o+ t, F: K/ Y; [
"road. Either increase the amount of roads "
$ k$ B' U! X' ~5 v& z5 L) \/ S& O "by increasing the GRID-SIZE-X or "
/ J. s) ~. w+ H" p "GRID-SIZE-Y sliders, or decrease the "9 X( f2 J( [) C) I* a2 I' D7 a
"number of cars by lowering the NUMBER slider.\n"$ Y2 ^2 w/ j4 w& D5 Y
"The setup has stopped.")2 e% X w: v5 B/ d) m/ _) K# S
stop- f' P, M G6 q
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5 [" M$ w& [ C6 P6 S4 e ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
6 D* _3 i& k, b; ~ crt num-cars
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setup-cars2 | K- h& O' U. q5 s
set-car-color
% l- n' W' @$ i, V. y5 r record-data
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;; give the turtles an initial speed: B, n5 U; s! p* n
ask turtles [ set-car-speed ] o, v# \, z6 Y/ |; B8 Z
$ k3 N; u$ W: {" m+ f# @ reset-ticks
0 D6 z" C$ ? xend: R5 T6 ~6 R, ?( P `2 \
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;; Initialize the global variables to appropriate values
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0 }; p( p, V3 D. c# T) F4 F set current-light nobody ;; just for now, since there are no lights yet' z* |& ^9 w0 T" `9 ~4 s0 v
set phase 0
' F% ]# k1 a( B5 T/ R% s; D set num-cars-stopped 04 l) N) Y2 s# Z G% Z! p
set grid-x-inc world-width / grid-size-x9 O Y4 }+ y) j( a6 b) b2 h* P
set grid-y-inc world-height / grid-size-y
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' A( V( M/ Z2 b( K0 A- T ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary8 K1 n# |, A! [5 |- X
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,# d6 X6 D, }# I, Q3 B1 J1 ^7 \
;; and initialize the traffic lights to one setting
& a, H) i) t* }to setup-patches
' }: k. ]- B: d# s I ;; initialize the patch-owned variables and color the patches to a base-color
# f% f8 A( [& i7 p( w ask patches
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set intersection? false2 }2 H T# O( f( ?( [
set auto? false! n* W( }) T7 W$ [ v
set green-light-up? true( m) Q9 p0 p1 [; w( M Z( t4 u
set my-row -1
# U, L( |' q/ W: x: a set my-column -1* c$ g; }) c( @- z9 V
set my-phase -1
" W, h: {* t2 }7 @5 L$ s6 Y5 u& w set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets. k8 R! ?' F1 x" k! s* Y$ w
set roads patches with s9 _+ p2 m8 b4 J
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
$ Y& f, B: e( l* G% c (floor((pycor + max-pycor) mod grid-y-inc) = 0)]& d2 R" y& z" C
set intersections roads with; E o T6 \+ ?+ F! ?- I4 q
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
( G ~- a! k1 T% b( ^+ N (floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 ^2 v; f$ z5 p; V0 ~7 g" I
5 l! p; x3 |" L2 W" j ask roads [ set pcolor white ]
8 I w, S8 k5 h4 i: G2 ?/ `: V 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?
% }+ @4 {& o" f) D" Z; t set roads patches with
2 a$ D$ `+ ^6 \& q+ G% a [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or# r) c6 s! r$ z/ b) ~7 v
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]& M! E" [/ C7 k! y' W
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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