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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。3 z# A' a/ S. X a' U) G: h
netlogo自带的social science--traffic grid这一例子当中,; r/ h X& \' R0 z! k, s/ [
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
! @0 @3 F: D9 y% N2 z3 | grid-y-inc ;; the amount of patches in between two roads in the y direction
" S) X. Q A8 T% A% z acceleration ;; the constant that controls how much a car speeds up or slows down by if& }: k- p$ T% J+ b: D# z B7 Q
;; it is to accelerate or decelerate
5 y3 H! L7 {5 F' [& D/ \ phase ;; keeps track of the phase
7 I2 o. N+ {8 h num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure' }! |3 q# V( J5 p: N0 U
current-light ;; the currently selected light+ r4 U% b% ]4 D
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;; patch agentsets
- f$ `7 z) d- S/ H5 G3 W intersections ;; agentset containing the patches that are intersections7 P0 S# M' a0 H
roads ;; agentset containing the patches that are roads4 k, z* T" G8 T
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turtles-own t) x- K* @6 z2 ]- d' }* p8 W
[
9 c6 D D9 b7 F; q' W% u speed ;; the speed of the turtle7 R& y. Z, A( p8 `& S& c
up-car? ;; true if the turtle moves downwards and false if it moves to the right# n$ `: P* ] y% K) N
wait-time ;; the amount of time since the last time a turtle has moved% g2 F# b1 i! {; R6 T" i6 J' C* Q/ v
]
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7 m. \8 P' c: V5 C; [patches-own
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( F3 q; H; _5 f intersection? ;; true if the patch is at the intersection of two roads
0 U7 V; @1 {1 M9 f green-light-up? ;; true if the green light is above the intersection. otherwise, false.2 E+ n/ E% y) t. G
;; false for a non-intersection patches.7 S, i6 d5 o& A) J4 Z$ T& t
my-row ;; the row of the intersection counting from the upper left corner of the
$ T6 Y6 o& l" C/ w* u ;; world. -1 for non-intersection patches.6 z- q/ @- V7 |* L# {+ A8 y7 q
my-column ;; the column of the intersection counting from the upper left corner of the
* A% a6 L+ m6 g2 z7 Z k ;; world. -1 for non-intersection patches.# I* ^ D- M8 v
my-phase ;; the phase for the intersection. -1 for non-intersection patches.' [+ ^: S4 n. d; o
auto? ;; whether or not this intersection will switch automatically.# J) R& S/ {8 h* X/ z* p) T
;; false for non-intersection patches.0 ?' E/ [+ z3 F+ W
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; F; u0 \4 N6 g% _. ?;;;;;;;;;;;;;;;;;;;;;;7 F& {9 w8 q3 g
;; Setup Procedures ;;- q- f. y: s; B1 t( n# q
;;;;;;;;;;;;;;;;;;;;;;+ b2 n0 M+ I: [; y
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;; Initialize the display by giving the global and patch variables initial values.# V/ `. V) C. [- Y) g
;; Create num-cars of turtles if there are enough road patches for one turtle to' o0 |4 }* Z: w' |3 _
;; be created per road patch. Set up the plots.
. r. ]# U9 l( R$ hto setup+ c- \* m/ ~% r' |5 S
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setup-globals9 g, U" e$ F+ C8 C+ Y
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;; First we ask the patches to draw themselves and set up a few variables
/ I6 F h) u, G setup-patches
; F; c* F& _/ N# { make-current one-of intersections
& M5 D4 B2 u) m4 f- y" r label-current. M0 I: d, j( a; h3 `: S
( i: ]* e7 t0 A$ Y: a" O2 o set-default-shape turtles "car"* J; V# K2 A+ P. q g; K
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if (num-cars > count roads): Q) s+ O) w) o& v" M4 o( m% l6 j
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user-message (word "There are too many cars for the amount of "7 j$ a: y3 |4 B3 O5 I4 C; d
"road. Either increase the amount of roads "" I) H1 A o; n
"by increasing the GRID-SIZE-X or "
9 }$ C( ~3 V7 ]$ c "GRID-SIZE-Y sliders, or decrease the "; p, W8 M. W5 O- D3 O
"number of cars by lowering the NUMBER slider.\n"
! U# D8 s1 r | "The setup has stopped.")$ [% N( M) y$ B5 P o9 |; ^
stop
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- n, f! [& N( G* ]$ l6 K& L& y ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color1 j" V- A' W# X
crt num-cars! D; d: U+ F7 C4 C* M3 B
[
% M& j& o( ~ x6 S. G setup-cars. Z1 t2 S3 p d2 ?4 m* w/ ~
set-car-color5 a5 s0 S s7 G* ^ v. P, j
record-data
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;; give the turtles an initial speed0 h/ c4 r! E6 q1 d, N* R
ask turtles [ set-car-speed ] d+ K# e* Y) e( l' }# `
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reset-ticks5 p) M$ l% j- x1 T% d
end
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+ V9 b. Q/ ?+ C* u;; Initialize the global variables to appropriate values
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' }, E9 q" u. Q# Z$ _ set current-light nobody ;; just for now, since there are no lights yet( |* i2 U( b6 y1 R) Y
set phase 0
) D) X& Z! @3 P% f8 s, } set num-cars-stopped 0( z" y8 q/ l: F
set grid-x-inc world-width / grid-size-x. n1 H' T# q, c) |' u
set grid-y-inc world-height / grid-size-y! E; J8 R4 \1 X2 a. {3 g
2 B) t! c: a/ R: ? ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary" X" P2 Z" c/ [# w m' ` }; [8 _
set acceleration 0.099
% J: D3 K8 i; Z+ i/ Tend2 |, ?* Z# a2 p" Y+ D, H3 @, p
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,$ X0 R! s+ T: l8 k# \
;; and initialize the traffic lights to one setting9 h& t, h" q4 H! k4 z
to setup-patches2 W# |7 I. U9 ?
;; initialize the patch-owned variables and color the patches to a base-color
3 S0 W, f: v3 e; W, `3 V' P ask patches
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$ i( D' E8 C! F0 ? set intersection? false$ x* F v1 h& O
set auto? false
& i- \; x, x/ Q! ~" Q! T# W, {$ t: o set green-light-up? true
0 G) ?+ s0 u! u, ], \; C. G/ I, r set my-row -1, T, {: _% b+ e. T& p; R! `& f6 L
set my-column -1
' Q1 u0 w& P+ D5 a; d set my-phase -1
" \; [4 F. P# O h* K; ~- P; h set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
3 C# ]3 b3 H4 z. c2 j; C set roads patches with
6 K5 f5 ?& t3 f [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ a' M7 s. Q( B+ \, s (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 T% h8 ^. ]. ^ set intersections roads with7 Y" s6 B& m5 u0 d# V2 R; M
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and1 d. y7 i; K1 Z- p5 Z. g. m
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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% Z% m% k3 B% ? ask roads [ set pcolor white ]
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end
# G9 F) E& g. T8 g) A其中定义道路的句子,如下所示,是什么意思啊?" B& M9 R5 f$ F) z1 z6 }
set roads patches with/ q3 b) D' ^" a. v
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ \- u- ~ F4 _2 C! s (floor((pycor + max-pycor) mod grid-y-inc) = 0)]& `( t. I) q: \8 d5 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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