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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。
8 m. q( K& l, Knetlogo自带的social science--traffic grid这一例子当中,
% k/ U/ a& M2 i8 h5 X) @6 ]; ~. [globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
2 ]5 ]3 h8 q: [ O! o) L grid-y-inc ;; the amount of patches in between two roads in the y direction
1 o3 @: o0 J1 G+ S: Z acceleration ;; the constant that controls how much a car speeds up or slows down by if' @9 ~5 t. `# O; A# o( c: i% @
;; it is to accelerate or decelerate
+ W, _+ s. a2 G a' b7 M phase ;; keeps track of the phase
( j. b3 q/ q2 u8 O8 E( Q num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure, {; \ O$ L6 Z2 {9 M" I P' J
current-light ;; the currently selected light H6 J6 |# u% S5 H' C
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;; patch agentsets
0 z2 X1 _* U' c6 m; [$ ] intersections ;; agentset containing the patches that are intersections
. u m7 H4 X8 p/ V" f7 c roads ;; agentset containing the patches that are roads" H( j/ C8 B( g
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/ m! Z) {+ K: }turtles-own
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speed ;; the speed of the turtle, P# L" ?0 b. B8 Q3 ]) Y" u
up-car? ;; true if the turtle moves downwards and false if it moves to the right% w# q2 X: y% M7 \, ^" o
wait-time ;; the amount of time since the last time a turtle has moved3 O1 a" a0 P5 \& N ?7 x
]
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patches-own
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/ n; Y& Q+ u0 n2 n- {1 g intersection? ;; true if the patch is at the intersection of two roads
1 M/ U/ |& E6 ?# [( g green-light-up? ;; true if the green light is above the intersection. otherwise, false.
, O" h3 J- f! g. U0 |; [ ;; false for a non-intersection patches./ m N' C( s" F6 `
my-row ;; the row of the intersection counting from the upper left corner of the
- J& n6 d5 W0 p6 j1 c h2 h" t: H( i ;; world. -1 for non-intersection patches.
% O4 h4 v! R& g5 U) ] my-column ;; the column of the intersection counting from the upper left corner of the
" J" Z4 A8 C' g# L( O ;; world. -1 for non-intersection patches.9 k9 j/ M6 K% g3 \6 ^0 Y
my-phase ;; the phase for the intersection. -1 for non-intersection patches. Y8 x% P2 E. ?( r# s7 K* k/ I
auto? ;; whether or not this intersection will switch automatically.! {1 N! G0 d/ Y0 Q' B" f" G+ I0 N
;; false for non-intersection patches.
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" ^ K9 U( [' J9 Q) `0 @+ _4 e5 U;;;;;;;;;;;;;;;;;;;;;;
9 _- j% f; ^6 w" u2 n& r' `;; Setup Procedures ;;/ M- ], ~& c( \, d
;;;;;;;;;;;;;;;;;;;;;;
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' k5 [. f2 a0 c- _0 Q. }& H0 E' N;; Initialize the display by giving the global and patch variables initial values.1 K; a) l7 b5 a5 Q; K4 h# f
;; Create num-cars of turtles if there are enough road patches for one turtle to$ K: a3 t5 Z, n) M! J
;; be created per road patch. Set up the plots.
+ I; F W6 N4 v2 M6 `4 e- P* v, O( r! dto setup
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! e$ ]6 W+ P4 T3 X setup-globals
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;; First we ask the patches to draw themselves and set up a few variables0 W" W0 P0 Q% }! e
setup-patches
( {$ i& v% h7 t) b5 a9 H make-current one-of intersections, ^9 A+ w5 K& U( L( O# ?, @
label-current/ k! F( y1 V9 Z3 L" N- l
3 m9 N5 h& A7 d# R set-default-shape turtles "car"' G& G) W8 p3 K, i+ K
8 Q3 M% C/ g( X. _/ Z if (num-cars > count roads)
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8 x2 l' l7 h: L) J9 _ user-message (word "There are too many cars for the amount of "3 m- ]( {0 e6 Y7 R6 ]: l1 a/ Y( c: N
"road. Either increase the amount of roads " Y. z$ `5 ^* }5 Y
"by increasing the GRID-SIZE-X or "
- _6 |. T- z2 d4 w0 q' q" Q "GRID-SIZE-Y sliders, or decrease the "; _7 S! g0 X; H4 p6 K* A
"number of cars by lowering the NUMBER slider.\n"
4 ] S L/ {% E# G$ g( d' F "The setup has stopped.")
5 W9 }& z3 i& m stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
0 t% V# a9 v7 P$ o0 m) | crt num-cars7 F2 }$ g( b1 l6 a8 t
[
3 k4 [; ^. L* r' Q. [+ \7 | setup-cars
& Y# b5 p) _/ i5 } set-car-color
1 [# H, n' O* z: ] record-data) \6 d# m1 V8 S7 K
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/ N, M. e5 B. b ;; give the turtles an initial speed5 o. @4 Q3 m3 C9 E. X
ask turtles [ set-car-speed ]
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$ H! e% W" L" d9 Z reset-ticks
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;; Initialize the global variables to appropriate values Z. r% c5 C& }
to setup-globals
! O/ O, P( F2 e# c" Q7 d1 \3 @ set current-light nobody ;; just for now, since there are no lights yet
- W) l \6 ]# b" S, L set phase 0
* _) S! H$ W3 a( K set num-cars-stopped 0
) x7 `- N* R5 A# r( @+ t set grid-x-inc world-width / grid-size-x3 s1 B. f+ Y" _1 B9 a
set grid-y-inc world-height / grid-size-y
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5 a) `) ?+ }9 C; M2 Z3 ~ ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary5 s' w& z* {' }
set acceleration 0.099
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# N$ r- J. G" q;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
: i2 {% u3 Y! X" C8 @9 i;; and initialize the traffic lights to one setting( U" U$ v0 @! Q7 g3 W0 f
to setup-patches
7 a3 u. j4 \* P9 k9 A ;; initialize the patch-owned variables and color the patches to a base-color
4 @8 A! ]* C8 n0 B, r% C' r" f ask patches
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4 B# ^4 O) _6 \/ ] set intersection? false2 w1 Q. \' I8 `+ A0 I. U
set auto? false
M4 { {/ R; V7 o set green-light-up? true
8 W8 G0 R6 x1 L. V" b set my-row -1
+ O5 [3 T- O( K ?% {- d set my-column -1
: ^2 j G% B2 S/ f set my-phase -1# B* z* \# `2 M7 O- C! Z
set pcolor brown + 34 z4 }0 s( N9 \/ v& j! K
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3 A. V% ^2 S( P' g2 a& B. r ;; initialize the global variables that hold patch agentsets6 K2 C7 g$ z% A4 e4 y
set roads patches with
6 Z. ?2 R& a) o [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* u6 Z: o, b4 d5 |6 Q" a0 u' v (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
4 T4 k' [. u: B: I+ ]! m. F. J set intersections roads with4 m4 ~3 i* {3 H# E/ T
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and9 p8 Z: o) i! s$ I
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]& `1 g6 u) P* b* s0 j% A. \3 b
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ask roads [ set pcolor white ]- V$ c$ \8 @: P D8 G9 V& f
setup-intersections8 {/ K0 t6 Y/ u1 }5 Z
end& D ^- H% C& y
其中定义道路的句子,如下所示,是什么意思啊?
8 s( T5 t5 y; W6 F! R8 Z7 c set roads patches with
' r. F8 K, K& R [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
, Z c; p2 o4 T3 P, Z. A (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; b# B" f. h1 q* n
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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