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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。" C3 Z9 \2 q+ Y7 L7 P
netlogo自带的social science--traffic grid这一例子当中,9 }& E) ~: ~# P% j3 D3 E
globals2 n: ^8 s: b# W4 `
[
6 G# i+ B( o! V5 ^1 a& g: P grid-x-inc ;; the amount of patches in between two roads in the x direction0 N3 ^5 S9 a' }
grid-y-inc ;; the amount of patches in between two roads in the y direction
2 c& U* v% o" f acceleration ;; the constant that controls how much a car speeds up or slows down by if K0 U4 n8 O$ b, g, }; Y ]
;; it is to accelerate or decelerate+ [" a3 ^8 K7 o. N$ \4 o5 U E
phase ;; keeps track of the phase7 a! D$ v4 k f4 D
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
2 y5 H! f8 e* A9 g' ]" d+ F current-light ;; the currently selected light
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- {9 K1 S: S4 v0 V5 j7 S ;; patch agentsets2 o, j3 |- p* z
intersections ;; agentset containing the patches that are intersections
5 F% Y% b) w' G2 L roads ;; agentset containing the patches that are roads
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7 {% z( P; `; J$ K6 lturtles-own+ J$ A- l/ @/ C; j
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speed ;; the speed of the turtle! Z" C" e# Z6 t
up-car? ;; true if the turtle moves downwards and false if it moves to the right
; ~4 b2 r& x) }) r0 A: X wait-time ;; the amount of time since the last time a turtle has moved( {, d, I# ] ^( `
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% G5 M% _2 e4 S0 \patches-own
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intersection? ;; true if the patch is at the intersection of two roads8 [" |- P& c' C8 ^9 M
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
, s$ g0 k8 z& A7 T% H6 C) z ;; false for a non-intersection patches.6 x- B$ k0 ]+ \# z
my-row ;; the row of the intersection counting from the upper left corner of the. @" q$ W/ {5 N0 R7 f) M7 G
;; world. -1 for non-intersection patches.
# A) U1 J* D; S- A# g; h; [; I my-column ;; the column of the intersection counting from the upper left corner of the/ Z. t' |( D j& E T$ a3 R# M I) c
;; world. -1 for non-intersection patches.7 } I' M7 M2 u* Q1 |( N
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
: m* V+ f! c5 N& I+ C! G auto? ;; whether or not this intersection will switch automatically.
; a! g; H- p4 `0 g! k5 A# G, r1 p ;; false for non-intersection patches.8 w& x& A. ^* r: H& j' H
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- o, A6 @( }( [( ]( O2 o% k;;;;;;;;;;;;;;;;;;;;;;/ Y. R9 g" s! O2 k
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.6 y6 I; `5 K5 N5 c
;; Create num-cars of turtles if there are enough road patches for one turtle to- Z. B8 u( g5 ]; K
;; be created per road patch. Set up the plots." d4 m0 ], d% ^
to setup
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables0 k7 j' O/ e& J( B0 `
setup-patches
$ @0 X& _& g& R$ b+ n make-current one-of intersections9 _% D+ M- T' {6 U& j' V' ~" N
label-current8 B9 Y! Y/ ?! `( W' [
( T- y2 S6 f; h8 u, | set-default-shape turtles "car"1 G7 p4 i) M) X/ A5 }0 k
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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 "
- {; `+ V! o. Z- ?' ?! a, W+ u "road. Either increase the amount of roads "5 z, y% Q1 X7 a# g8 D
"by increasing the GRID-SIZE-X or "
$ |( z( [: J/ _$ }8 |! d* I "GRID-SIZE-Y sliders, or decrease the "
' _) p8 Z% e: l- s. K S "number of cars by lowering the NUMBER slider.\n": c! e u- m) Q2 B
"The setup has stopped.")
% M& T) F# \- O" [9 t4 R/ @ stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
& D( p" _& [0 W e1 f3 R( m crt num-cars
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7 N/ W4 [+ B, B/ f* o; t8 D/ T setup-cars6 R' Y* V) e2 s, h5 J% _; Y' U) Y' h
set-car-color" L! k: {4 r! h$ ?6 }
record-data- O3 P- q, b0 U' G! O
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;; give the turtles an initial speed
* o, s; h ]# V8 T9 E/ p ask turtles [ set-car-speed ]4 f4 b# B3 P: A J
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reset-ticks
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! Z2 D- A6 N/ M! |- X& W;; Initialize the global variables to appropriate values* K* o% n5 d; p+ L6 p/ V
to setup-globals
3 P# p1 E+ G1 E* @: Y2 R( V# Z set current-light nobody ;; just for now, since there are no lights yet
3 I% N1 s3 B- t0 E' Z6 n- ?2 w set phase 0
5 m/ R5 @; o/ F+ o% T: K2 ` set num-cars-stopped 00 V( q9 @9 h+ l, D: L% ^" }
set grid-x-inc world-width / grid-size-x7 ^1 u; C% e+ `1 |1 Z$ M9 _- v7 D
set grid-y-inc world-height / grid-size-y2 [1 e! D2 d2 y% f, h
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary% o5 f1 i( A3 r; t
set acceleration 0.099
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: R0 R3 y; a; i8 G+ x;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
- J8 b1 j* W, F- i7 e: x* w y;; and initialize the traffic lights to one setting3 H7 V6 N1 e7 o" M7 T) D9 E E# S
to setup-patches$ D7 K2 Y; U& i$ W
;; initialize the patch-owned variables and color the patches to a base-color
. a q2 d4 [; v% H$ ~4 c3 O0 w ask patches5 y8 ~8 g- n$ u3 I" E* N+ B* V- O% q
[
2 O% x' J: b q6 |7 | set intersection? false* [3 k. U+ j0 f" W# E! O
set auto? false: T! `: P8 K% W0 i* K, b% t s8 ~
set green-light-up? true, V) x a! C, h; c8 [
set my-row -1
% C( A' Q* {* y. E2 }8 C set my-column -1. ^9 |4 o- } G
set my-phase -1
) l8 E0 g+ K8 k" G- x set pcolor brown + 3
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* `$ u' Y1 w" T& x" A* T/ d ;; initialize the global variables that hold patch agentsets6 G# m1 |5 u. y. j& {! S4 s
set roads patches with* x8 Q9 {) n( e& Y4 m
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 f; o5 q: H7 Q+ I9 X' J% O (floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ @) w3 [8 c7 _/ @+ Y
set intersections roads with+ E2 P1 S L6 C: p0 Y# \
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
8 x! F- q9 N8 ?- J a3 \, ]* R, E (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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end( T( V6 @! n6 L0 j) l
其中定义道路的句子,如下所示,是什么意思啊?6 g$ `- x& R% D; r8 \
set roads patches with0 O# [( D7 L; K n
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or+ R% e2 h5 w1 V
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, H: y& Y, l: O1 g" Y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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