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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。
: F6 g; d* @2 Snetlogo自带的social science--traffic grid这一例子当中,
& z% K: N) S1 S2 k3 q, Kglobals
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' E L7 t+ K' I# g; T) m grid-x-inc ;; the amount of patches in between two roads in the x direction! X' A3 g5 c* S- e0 l1 G( {
grid-y-inc ;; the amount of patches in between two roads in the y direction
2 P4 }* I* D _4 H+ H. H' r acceleration ;; the constant that controls how much a car speeds up or slows down by if
# P7 s9 t) s4 G! P5 i ;; it is to accelerate or decelerate& e: Y& `7 S0 E" N& J2 j
phase ;; keeps track of the phase
6 @5 `) ^ A% ]: M' i, P4 W0 U8 S. b: a num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure% L* F( F) z* r2 ~: Z
current-light ;; the currently selected light% l( C {1 x/ o4 y5 r( ]
, K% l* E6 ?5 i8 w3 d! B9 {9 t ;; patch agentsets
) ~( V* |; J: Y( c5 i7 V6 v intersections ;; agentset containing the patches that are intersections
7 l3 X k" D& [5 l$ B& C5 m) h roads ;; agentset containing the patches that are roads) ^* e2 \. x3 d i0 ?! {' u
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turtles-own1 T6 c( F5 z% e3 w
[
9 L1 O# E8 ?! \6 l, O# H/ g& ? speed ;; the speed of the turtle5 @* e" ~( w& m! F
up-car? ;; true if the turtle moves downwards and false if it moves to the right
t& x2 M1 Y3 Y6 Q wait-time ;; the amount of time since the last time a turtle has moved2 t# d' \0 m# ] v% `2 E% F
]
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3 y) B+ Z5 T2 M) m' C, @ xpatches-own' U) E3 ] U( p2 o8 H- z
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intersection? ;; true if the patch is at the intersection of two roads
. D& s D9 z P+ o* ^ green-light-up? ;; true if the green light is above the intersection. otherwise, false.
: l% y7 t2 G7 _( k* w) q: ~; M ;; false for a non-intersection patches.
6 n! r; Z% ]+ ` my-row ;; the row of the intersection counting from the upper left corner of the
6 Z9 S ^0 P9 o& n ;; world. -1 for non-intersection patches.! d6 n6 m0 X- y( i- d5 p
my-column ;; the column of the intersection counting from the upper left corner of the
* k3 R# l2 U' U' P/ X ;; world. -1 for non-intersection patches.
F8 Q# t4 W1 }% t1 Q my-phase ;; the phase for the intersection. -1 for non-intersection patches.
* m# F) c) G* Z" s+ A auto? ;; whether or not this intersection will switch automatically.3 x+ A8 |3 @8 p$ n" ]
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;1 ^2 W- ~9 Z. Z; Y7 A% c1 j5 a
;; Setup Procedures ;;
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1 L" q$ C' N l;; Initialize the display by giving the global and patch variables initial values.4 U1 L. U; c( E$ R
;; Create num-cars of turtles if there are enough road patches for one turtle to8 w0 l" P3 C7 r2 Y0 n. ^
;; be created per road patch. Set up the plots.
6 Z7 q; s. o, o! l: ~$ h5 B' bto setup& G2 u+ w& t$ R' |
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setup-globals
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8 ^5 N2 |8 \2 V" v+ s# k. g2 s4 K ;; First we ask the patches to draw themselves and set up a few variables
3 N! ~) ^# M4 E7 \/ M4 f) f) {! | setup-patches; r7 [2 r" e( J) b, e
make-current one-of intersections5 C+ v3 w) [( a1 `7 |3 R% L
label-current2 j; s4 e" ?) a2 B1 v
2 _5 v2 o( l6 O( ?4 _ set-default-shape turtles "car"6 e2 X- K# C; V# I+ M' K \
5 \, H7 d- E& Q if (num-cars > count roads)% c7 g- o2 K$ I8 H; {. Z
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user-message (word "There are too many cars for the amount of "
; Q+ s( J+ D* ^7 z9 m "road. Either increase the amount of roads "+ B- D0 U8 e3 Q
"by increasing the GRID-SIZE-X or "
5 e" V! i/ g6 E- z8 a8 { "GRID-SIZE-Y sliders, or decrease the "% b3 o% J S7 ?+ n& s% U: C
"number of cars by lowering the NUMBER slider.\n"
# s6 h# T* x c. r ]4 k0 o4 d+ p "The setup has stopped.")
) y6 X" U: w+ X6 i+ O, B stop$ x( Y- L5 G9 F2 P J# f
]
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, M5 \% V( V$ {" s8 Y( ? ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color5 c: Q/ o% k( s9 w
crt num-cars4 h3 ^6 Q- }7 g1 ]6 u; u: \
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2 R' [1 [; y6 |# M& n; |4 ~ setup-cars" u2 J. P& M( L0 ]& S* I6 a8 T
set-car-color
4 D& n; m5 Y1 ^ D) c record-data$ f( m2 W4 [" o+ I6 ^. R
]
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* \' P; `3 ]0 b; j: Y' @ ;; give the turtles an initial speed
X w& `" D7 v/ @! U/ } ask turtles [ set-car-speed ]
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reset-ticks$ v% [9 G+ s# a
end
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, c5 d/ e+ g4 u9 p L( B;; Initialize the global variables to appropriate values2 {; u4 B& @+ E; [
to setup-globals8 ?$ N' M. O& y4 e5 r: C2 n* y0 U
set current-light nobody ;; just for now, since there are no lights yet- L2 @* B1 Z1 m; B
set phase 0- x8 [" C! D; [9 g3 A5 h, t
set num-cars-stopped 0
$ O+ z0 p2 S& l8 B* t5 N set grid-x-inc world-width / grid-size-x
* b8 N' @- }/ ?7 s set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
& c5 J, R8 X1 v/ N0 c set acceleration 0.099. P& {4 {3 A/ j& [& D
end
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; F& S" w. S5 h8 ?6 E;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
* d) i9 o" L) m+ ?6 `% M9 q5 z;; and initialize the traffic lights to one setting
D% I+ d9 ?" f0 U. Xto setup-patches) t* B" E% {+ ?7 _# Y: p
;; initialize the patch-owned variables and color the patches to a base-color/ k& s* \8 l$ b1 b: f
ask patches
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3 d8 P6 N6 @" y6 W% T5 Z5 f set intersection? false
/ Q1 j4 O& [0 V! T set auto? false
& V; v* r" B5 ~5 v" ~ a set green-light-up? true
2 n$ Y1 ^/ c+ k% g set my-row -1' ~- _% j5 j) N4 O: n2 S
set my-column -1
% H8 T& `+ Q) o8 a O3 @ set my-phase -1
; ]: q/ T( W$ M* d7 K) M( B set pcolor brown + 30 `7 X( \5 b# m0 l2 D
]
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( K% Y/ D2 u/ q" a+ u$ S ;; initialize the global variables that hold patch agentsets$ T5 o* n* t. e8 U0 N# l
set roads patches with4 d4 K7 J$ C1 S. J7 ]
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or. X9 U% }6 ^5 w
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 z" z# P# p- {
set intersections roads with! } M( s* n+ [7 O* {
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and( o+ x; q( t; C" E& V
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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8 {$ b3 y/ \6 ~0 W$ M$ b7 t/ ] ask roads [ set pcolor white ]
$ \6 v# O9 f6 n" A. f7 Q& }# s. F setup-intersections" w' m: k; t6 n w6 c! t J5 a
end# o* s2 k0 A7 g, j+ U
其中定义道路的句子,如下所示,是什么意思啊?
! t9 T! I3 Y9 V set roads patches with4 ]5 d5 @. K4 c/ y- \1 n9 \
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 ~" p5 ?; E- I; z' Y6 S (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: ^- n$ O' s& {. S( M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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