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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。( x6 N1 z l: J: G e
netlogo自带的social science--traffic grid这一例子当中,( y8 C% i7 D/ H: X" B$ K
globals. E8 J+ G& j8 I6 T1 w& q5 g1 `
[
7 |6 @7 K$ I9 y8 C. } grid-x-inc ;; the amount of patches in between two roads in the x direction, s# R4 B, |; j4 g1 R2 Y/ ]" c/ n4 `) }
grid-y-inc ;; the amount of patches in between two roads in the y direction0 e' [2 P' S+ H) O. j( R$ I
acceleration ;; the constant that controls how much a car speeds up or slows down by if
! V3 R+ i9 V& m$ y0 f ;; it is to accelerate or decelerate
4 C9 D7 b2 p5 x phase ;; keeps track of the phase. E# B4 x1 z y" z
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
t( G& {! H+ s% { current-light ;; the currently selected light
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5 R$ Z$ C* Z% w1 G' K8 H% s ;; patch agentsets1 o3 X J! o2 h( a( k# k) a
intersections ;; agentset containing the patches that are intersections
7 F9 i- V! K3 R4 S roads ;; agentset containing the patches that are roads
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# p% e1 H. x- ~turtles-own
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. Z% c" H6 Y4 Y, Y) u- o+ E G speed ;; the speed of the turtle3 r! w- U9 H- v* H' W1 `
up-car? ;; true if the turtle moves downwards and false if it moves to the right- b' ]4 |: y/ X, U7 G% `1 O) ~1 Y
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own- |7 @: w* i4 C% c
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intersection? ;; true if the patch is at the intersection of two roads
* G7 ]; v3 {4 x- I/ p/ x! h green-light-up? ;; true if the green light is above the intersection. otherwise, false.8 f8 o; M4 M. C# L" R" l
;; false for a non-intersection patches.
( K! q! `4 p& z* B& A" m* x* t my-row ;; the row of the intersection counting from the upper left corner of the
: v8 w, b; ^2 b$ m! n ;; world. -1 for non-intersection patches.
( M! h4 g5 r5 u N9 d2 t my-column ;; the column of the intersection counting from the upper left corner of the& @; `# v: T$ J8 C J; s1 ~7 j
;; world. -1 for non-intersection patches.
% Y/ v: V2 Y5 b my-phase ;; the phase for the intersection. -1 for non-intersection patches.! p& b! @; n c; L, m
auto? ;; whether or not this intersection will switch automatically.0 z7 w. j5 q V- Z8 `: c/ v6 ^3 V
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
5 O! i" q# z9 x ~7 o;; Setup Procedures ;;. a3 M3 Y" R) e& R# G5 j
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
1 v8 O/ @- I* l+ h7 Y4 x;; Create num-cars of turtles if there are enough road patches for one turtle to1 ^ m/ r1 J# o- n* L) M
;; be created per road patch. Set up the plots.6 F* z$ k8 a5 v% O
to setup
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setup-globals( r' H% r! h( I
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;; First we ask the patches to draw themselves and set up a few variables6 B% m, o2 A. r9 { r
setup-patches
5 W9 U4 ?2 U4 P# E make-current one-of intersections* p$ R. ]$ F9 f! w4 B
label-current
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set-default-shape turtles "car"4 R0 e- d" l/ D3 l2 C* ^1 R' E6 g
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if (num-cars > count roads)
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7 ?3 x4 c6 h( c user-message (word "There are too many cars for the amount of "# D( I/ k, \; d
"road. Either increase the amount of roads "4 @8 G0 K9 J% r2 a: ^) [8 G
"by increasing the GRID-SIZE-X or "( @' Z8 Z7 s( L( Z" f
"GRID-SIZE-Y sliders, or decrease the ". I% |% {3 [1 q4 t/ {7 o
"number of cars by lowering the NUMBER slider.\n"
: d: d& Z( j4 H/ b5 f# `- u "The setup has stopped.")
$ w9 ^: C% c# ^: @- Y2 k; {: a# Y stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color8 h8 Y$ f7 P1 r0 \+ Y7 y$ S1 A
crt num-cars
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setup-cars
! E0 g" L3 D; d2 r! u set-car-color
$ r& `$ F% |. T7 v. E% |4 i record-data
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* W) m& j# B- k n8 L ;; give the turtles an initial speed
5 ~7 s9 F( a1 b: G4 W/ g ask turtles [ set-car-speed ]) S c: M% e0 |
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reset-ticks( o* o& B! g9 ^1 q
end
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! ^4 [+ t+ v3 H2 K' M& U& s( q;; Initialize the global variables to appropriate values0 `" n3 L& E. U0 d6 @; }
to setup-globals: v# O: e6 G4 r* y& h3 ]" s2 U
set current-light nobody ;; just for now, since there are no lights yet
: _4 n/ a& j! I! Z7 u( ] set phase 0+ y3 Q% B0 s% _' n6 c; g ?* N5 D
set num-cars-stopped 0
1 i5 C1 k9 P: p5 l$ x/ H set grid-x-inc world-width / grid-size-x9 n# P' T% l* W; @, I: h* X+ _# c$ G
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
" q' A5 \- w+ a" O1 c- U: I set acceleration 0.099
+ {; \2 s" l, q: send3 Q h- o( l- G( u+ g& Z) R5 G
( c/ [- B6 D' X& w0 v;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
E. [5 O/ c, L/ o;; and initialize the traffic lights to one setting
# T5 f2 \0 Z! ~, L0 jto setup-patches9 ]0 z+ z& W* K( y
;; initialize the patch-owned variables and color the patches to a base-color
( O1 g. W" |/ M3 b P9 I# ^ ask patches( k% u& c: C1 X# t! r
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set intersection? false1 w+ `+ U8 ~& G! g
set auto? false8 n" P) R& t+ [7 ^7 `
set green-light-up? true K: K6 l5 ?2 r$ p% c( Y
set my-row -1
|7 s6 I( A% P set my-column -1
( A$ B V' _# L/ { set my-phase -1
b9 i" r2 Q4 J% o- N; q$ L9 }# c0 G( S set pcolor brown + 3& D$ Q$ w/ t6 b* r
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;; initialize the global variables that hold patch agentsets
) ^9 C% d9 ~- x9 v set roads patches with
+ L7 n6 d5 I7 |+ x) {) Y- e [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
% @" t- H, L" g$ b/ q( N (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
+ j0 R. i5 @1 f/ N6 v3 ` i. E set intersections roads with ~9 v, w9 d2 u6 q; t q
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and, q6 Z' z: T, G" F* S
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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, o' K; h+ ~- u2 L6 ^/ S) R2 b$ r ask roads [ set pcolor white ]
" N4 n) }6 g' W% k setup-intersections4 ?1 ], B; f+ |) l) d) |8 T" ~6 g
end/ y, S) C \6 @' W
其中定义道路的句子,如下所示,是什么意思啊?
) V9 z! O7 _3 g, X set roads patches with8 I- |* s+ M0 R, F5 b
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or/ |- M8 G/ D7 |
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
`/ K i/ V7 h* V1 P# v% m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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