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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。
5 P$ _2 v$ ~; F0 ~" [. q. c, g0 xnetlogo自带的social science--traffic grid这一例子当中,
3 n( r2 i. _2 H7 B: t- Rglobals
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4 v; w# X5 x ^* z7 M$ P$ D grid-x-inc ;; the amount of patches in between two roads in the x direction
2 p( ?: x/ D+ U8 K grid-y-inc ;; the amount of patches in between two roads in the y direction
: W) c2 v- R" t: @ acceleration ;; the constant that controls how much a car speeds up or slows down by if
6 u6 z6 {2 s# ]: |5 A ;; it is to accelerate or decelerate
* q; |; f2 k9 w1 f& T7 i5 R$ v2 M phase ;; keeps track of the phase
( u4 r3 x! q- h: t4 H num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure- a3 \/ B6 m/ J) o4 M
current-light ;; the currently selected light
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;; patch agentsets
3 `1 t5 W# h% L intersections ;; agentset containing the patches that are intersections
$ ]* Y* Q( T$ \: G. v9 Z! Q- q, S roads ;; agentset containing the patches that are roads
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& v4 `% F9 U3 M Y# H+ P y6 Oturtles-own1 x4 b$ O( Q6 ?, H' O
[
& c a v7 o5 p& ? speed ;; the speed of the turtle
+ G1 ], x$ M- y- f8 |. P. q up-car? ;; true if the turtle moves downwards and false if it moves to the right
" b# S W2 A8 |! h o wait-time ;; the amount of time since the last time a turtle has moved) r- m0 g+ H1 M: S; j4 T. M0 t
]
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' B. R# q) T9 P' lpatches-own
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7 k! A8 |$ O1 v2 R+ T; Z( g intersection? ;; true if the patch is at the intersection of two roads9 i7 Z8 N- [# Z2 R
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
; A( ?0 M4 L3 O1 n+ { ;; false for a non-intersection patches.0 {8 T9 R% J! ]" k8 m/ n
my-row ;; the row of the intersection counting from the upper left corner of the) r% K+ s' v! n: N
;; world. -1 for non-intersection patches.
. n: l& g: @+ u" d my-column ;; the column of the intersection counting from the upper left corner of the4 M- i1 j2 Y Y. s
;; world. -1 for non-intersection patches.
$ P y8 i S3 N( Y9 F8 q+ P' W my-phase ;; the phase for the intersection. -1 for non-intersection patches.
7 h- n: T" {# }3 b% f auto? ;; whether or not this intersection will switch automatically.) T2 f. O% s7 V% o
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
2 H) c c# t1 H) };; Setup Procedures ;;, s+ y; |! N" D7 {( E& p
;;;;;;;;;;;;;;;;;;;;;;
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( Z& W1 o. B; ^;; Initialize the display by giving the global and patch variables initial values.
1 y; [9 d1 ^! _4 U3 L, E' R9 z# g;; Create num-cars of turtles if there are enough road patches for one turtle to
@' R: J9 h6 U. ~! u' S5 t;; be created per road patch. Set up the plots.0 |# r/ i. Y$ {
to setup9 Z3 |. [0 y5 \8 }. O
ca
1 p' A6 l" u Q" F D setup-globals
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3 ^2 v$ i s! y4 y2 \& G5 g/ ? ;; First we ask the patches to draw themselves and set up a few variables
7 X* ~ M; S5 k/ T1 @2 {5 L3 P setup-patches) g# `1 D0 V3 }! m* B+ `
make-current one-of intersections# W0 s- h7 d8 O. I( \. x
label-current
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* J+ u, R) n% j% ^3 x set-default-shape turtles "car"
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if (num-cars > count roads) h- O$ |. x5 M7 F
[
2 m+ B5 b* {6 d; e3 H; T user-message (word "There are too many cars for the amount of "5 ?, x) a) X6 X* @- g" O! ]; d' Z
"road. Either increase the amount of roads "
0 X3 R/ I5 k2 d$ W5 K "by increasing the GRID-SIZE-X or " y5 D% s! `+ a
"GRID-SIZE-Y sliders, or decrease the "
1 J9 ^' C7 ^" |! f, G5 P# e "number of cars by lowering the NUMBER slider.\n", a( T% c% V1 m5 O
"The setup has stopped.")
7 f2 @5 ^5 m3 K0 t stop
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8 H* T7 A: R. T; ^0 a- O ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
$ J( H5 ?, D- Y+ ~; J crt num-cars; ~ J+ c* D* y+ ? c% l
[
1 G- Q! s6 n2 `0 n' U- U1 M setup-cars, v9 l' ` t' ^& I& U
set-car-color+ u- k5 X& S* i, q% t- ^9 ~
record-data- T2 Z4 j0 o6 \- V' P
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) k; ~7 \. y j3 _* P: W5 q( P ;; give the turtles an initial speed4 ^0 g! E3 k) J/ N% p) X
ask turtles [ set-car-speed ]
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% e A! O: _/ w+ @. R$ _- V reset-ticks8 ], Y4 e! z% Q; N9 E( R* s7 f$ l! b
end7 A, l3 z0 d9 H, t! B1 ~
0 ]; [; g7 c& }7 u" z3 I, e;; Initialize the global variables to appropriate values( v; S4 S6 l5 e7 {6 V8 `& e# f7 `7 ~8 ]
to setup-globals" C, }: r: z/ x9 t
set current-light nobody ;; just for now, since there are no lights yet' S3 S: [* a0 R* S
set phase 0( S% d/ ^! C( @
set num-cars-stopped 00 g6 f: Q' H2 T
set grid-x-inc world-width / grid-size-x
0 O, D m" m8 B set grid-y-inc world-height / grid-size-y: x8 t, \, G h" ] G. Y8 R1 M' O
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
7 Y% Z" f% D0 R/ W9 f set acceleration 0.099
+ {9 y& @7 V; Iend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
1 \5 Y, {( E ~' n. A7 d;; and initialize the traffic lights to one setting% u6 C) H1 F8 b( b& @2 h
to setup-patches
0 U, J% ~- ]$ X0 f/ e* I ;; initialize the patch-owned variables and color the patches to a base-color; Y- Y+ v1 |# o5 [+ n- D* o- W
ask patches( \/ @: }9 c- K8 m: k' s
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; H* [" S g9 c7 Z" v5 @ set intersection? false8 @3 j& T& F7 t. J; W3 d m
set auto? false) a* r+ d( { Y
set green-light-up? true s; \# i# ^" [" r
set my-row -1# e# c8 |* S* {2 t8 ~1 B5 _
set my-column -16 a( q8 z% o1 {, K, k6 z
set my-phase -1
0 `. K: c( m/ \) ^1 y' ? set pcolor brown + 3
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( u/ ^2 T1 [2 t) P2 e# J ;; initialize the global variables that hold patch agentsets! l! e( h: X5 o1 F) t+ {( Y9 X
set roads patches with# g! f) r2 p. x% a
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or- d% j) q* n; c
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 i3 Z5 r r# s& f- T& H, g
set intersections roads with
* Z/ c7 Y& g1 r$ Z& O [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and! O+ ~3 X# B v: j- S8 q4 c O" ^ l
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 H: `0 j7 f0 {& o, J. M9 ~/ }0 U
5 Z' X( U0 N+ |- E" e ask roads [ set pcolor white ]
# V; Q c$ u: `# T4 } setup-intersections
, {2 C9 w% L4 Q Aend- x/ h) b, K- p
其中定义道路的句子,如下所示,是什么意思啊?
2 E& w4 @* u4 }$ U# q! u& J- f set roads patches with
* i6 v1 i3 F! `6 o9 O+ y5 f [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
0 A! D4 d6 \& R5 Y7 H8 m$ Y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 e9 D3 l5 T+ d8 [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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