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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。 b6 V6 Z3 Y( t" C. o' ?# v
netlogo自带的social science--traffic grid这一例子当中,( ^* Y, {% K1 _8 P r
globals% Y2 I. @7 ?6 O
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grid-x-inc ;; the amount of patches in between two roads in the x direction
0 e+ {/ i8 @5 a) n6 V( } grid-y-inc ;; the amount of patches in between two roads in the y direction
% V$ a+ u$ r) {' y0 G% d acceleration ;; the constant that controls how much a car speeds up or slows down by if$ @+ i, ~. {* H% s. ?3 D5 c6 ^
;; it is to accelerate or decelerate' Q) N" j, y/ l8 B- l
phase ;; keeps track of the phase! M/ B5 {7 a8 z# b" Z, Q
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure( o) w% u$ v M. N: c2 @, x
current-light ;; the currently selected light
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;; patch agentsets
) ?2 e. u: u: T intersections ;; agentset containing the patches that are intersections
4 R/ U! H( W' k% ~9 Z9 h' A roads ;; agentset containing the patches that are roads/ {- X0 v0 y5 W. w9 h
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turtles-own: d* Q$ Q3 M' a
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speed ;; the speed of the turtle" \: v2 f2 m# t% i4 O& ~( D
up-car? ;; true if the turtle moves downwards and false if it moves to the right1 r+ r4 i. d6 N6 D# M
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* B7 C( F8 l9 y9 t% ~; v
green-light-up? ;; true if the green light is above the intersection. otherwise, false.$ p0 v- r9 s" K ^
;; false for a non-intersection patches.0 l# n0 i8 G: z$ w4 L
my-row ;; the row of the intersection counting from the upper left corner of the* |4 c. }% \! i. x" L2 I
;; world. -1 for non-intersection patches.
9 u) F) s! D# Y my-column ;; the column of the intersection counting from the upper left corner of the8 @- D% j0 ?/ R6 f* K
;; world. -1 for non-intersection patches.6 y0 g$ W3 Q) j7 X2 @5 X
my-phase ;; the phase for the intersection. -1 for non-intersection patches./ m# g; I' _: a4 \
auto? ;; whether or not this intersection will switch automatically.- a9 S& @ m6 D0 {2 Z! x: s' X
;; false for non-intersection patches." Y+ d1 V8 D2 k5 [2 o
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;;;;;;;;;;;;;;;;;;;;;;
( r9 N5 F0 W( p- V( ~;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
" C! M% G2 f; c A+ I1 I+ i;; Create num-cars of turtles if there are enough road patches for one turtle to2 b. [0 d* X; W
;; be created per road patch. Set up the plots.
/ r( y2 D6 ?/ ^) f2 r0 Mto setup' S7 q, G7 ]* |8 S, \# `
ca
6 M4 `9 O& E7 T* W+ h) l, S- q3 @0 z setup-globals' s6 F; V! H: j, A) x4 w
j5 B8 p- A1 U& x ;; First we ask the patches to draw themselves and set up a few variables- d1 ^# s9 u( b2 v9 h$ K' I9 \
setup-patches1 J6 D; K+ p1 {; C+ | ^: b
make-current one-of intersections
3 c/ q1 U* z& N! A# _ label-current
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: V/ F# Y ~% L/ a6 _7 X set-default-shape turtles "car"- i! e7 e/ p0 h# V
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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 "5 i% _/ R% C% q, N: |; s
"road. Either increase the amount of roads "
* P n: J" O* _( v7 V! h "by increasing the GRID-SIZE-X or "' i1 c. ?% Z. W* ^8 v+ E
"GRID-SIZE-Y sliders, or decrease the "; n! C1 ~3 A* N4 `: }- t
"number of cars by lowering the NUMBER slider.\n"4 v8 q) o$ r7 x5 Z8 N8 n' H
"The setup has stopped.")
I8 C) w m, J4 u5 C# L5 Y stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
& r3 Q u$ ]/ B. ]& K8 u crt num-cars
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setup-cars
7 o, g d3 {1 b# W& p# h" X9 t set-car-color
/ a! }* c+ b. H8 v6 f record-data0 @, w; _% d, ]( Q6 D
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;; give the turtles an initial speed. M% S# P4 g& d# C# @2 z
ask turtles [ set-car-speed ]
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reset-ticks
4 [: w% U5 u- O O7 Yend
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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
9 f, l" R( O& ?3 D1 |* u set phase 0
) e2 ^/ {0 ?$ [2 ] set num-cars-stopped 05 o/ c# u" B$ K* T2 ^4 h
set grid-x-inc world-width / grid-size-x
, {- I- U, r+ [7 J0 m# Z, c set grid-y-inc world-height / grid-size-y* [, U+ p: r' x
5 O$ I/ O; o( [ Z ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary( d3 x' w3 ~& [! e) t# _
set acceleration 0.0993 F+ z- S- r5 B9 E$ b
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
: x, L* F! D4 |. ` N$ p;; and initialize the traffic lights to one setting4 p/ J) x( T/ e1 H% x
to setup-patches0 Y V( T0 B9 k) B {$ z
;; initialize the patch-owned variables and color the patches to a base-color
. Q% ^# t& Q$ I# }+ ~( O ask patches# X; E2 T2 }7 L* j# c; G# h
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set intersection? false' V/ i0 u2 o! ^% I
set auto? false4 E# q$ @4 m& z' @
set green-light-up? true! i- U- m; {. ^$ W
set my-row -1
, `- B$ W" g7 v, | set my-column -1: C% R9 L6 H4 q6 e+ o
set my-phase -1. O* I- _0 Q4 r- l/ v1 x
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
~# `% `# w* d: D8 l set roads patches with
6 S/ A3 O: f; d0 n& ]$ z1 V& `* b5 [ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or+ K/ r: Q/ D) H
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' F! x7 {: |2 }3 o set intersections roads with
* w) N8 \9 M4 s0 o& d- A [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
4 f) d' h9 ~7 F4 t4 B0 X4 }3 O. M' ?, | (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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end
% Y* [' L% ~2 }; Z" g其中定义道路的句子,如下所示,是什么意思啊?
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9 w5 D S0 k; e' N [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 G/ j1 T: f9 j1 A+ P0 _0 | (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 h5 T. s$ V0 k4 B0 ^5 P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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