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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。
$ n$ R! e" X; |' ]4 E" J9 xnetlogo自带的social science--traffic grid这一例子当中,
7 y; b& I) q; f5 |globals9 n6 E& K5 S, W7 a
[+ q7 Y8 V8 y: Z7 J! ]
grid-x-inc ;; the amount of patches in between two roads in the x direction
/ q3 {! Y5 N R: F) j grid-y-inc ;; the amount of patches in between two roads in the y direction4 ]" D- h2 Y' N% ^
acceleration ;; the constant that controls how much a car speeds up or slows down by if
+ o+ T4 V( i, D6 e: g8 N% Y ;; it is to accelerate or decelerate
! t; I; x: v+ C1 ^! {& h phase ;; keeps track of the phase
' p/ p; d3 b# }+ `; @) f num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure; i9 h2 {( c' M* D& l% b7 D! J
current-light ;; the currently selected light0 z$ Z3 V' U% i8 r4 r- {, q2 Z: P
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;; patch agentsets' s2 U3 j7 [" g! B; [( }- f% Q
intersections ;; agentset containing the patches that are intersections4 x; x% `( ]1 D' e
roads ;; agentset containing the patches that are roads0 B( A9 F; g! d3 ?( |8 g. ?/ e
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) s& F: K# V! L2 P' H7 ^# ]7 pturtles-own
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speed ;; the speed of the turtle
2 X& N9 y! K3 K2 ]( T0 K j% K up-car? ;; true if the turtle moves downwards and false if it moves to the right6 _& \/ T5 r' _+ `3 W) t( ^- N
wait-time ;; the amount of time since the last time a turtle has moved: N J [6 W9 I8 ^- Y; c0 q- H
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patches-own& f6 K4 v! @/ c3 O, i5 s
[
/ S9 \, S% z& |* y/ X) a0 w4 c- u intersection? ;; true if the patch is at the intersection of two roads
" R; R) X$ D9 x1 i green-light-up? ;; true if the green light is above the intersection. otherwise, false.% R& N" x# q: [) }. @1 j0 v
;; false for a non-intersection patches.: I/ g0 c+ y6 ~0 G! u$ e! [& P% Z
my-row ;; the row of the intersection counting from the upper left corner of the" a G! v% G$ n* N! l
;; world. -1 for non-intersection patches.
* w2 l3 j. b$ H4 I; Z0 W0 m9 b0 | my-column ;; the column of the intersection counting from the upper left corner of the
' y" s8 v: N* @# h l3 O ;; world. -1 for non-intersection patches.# B: ^) r3 i6 c) Q, F& W* S
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
6 `! f8 }; d3 @- | auto? ;; whether or not this intersection will switch automatically.6 w# v, u. R# P# v7 x
;; false for non-intersection patches.2 N& @+ W8 R! e
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;;;;;;;;;;;;;;;;;;;;;;$ ]6 V4 T& H; r' a( s% r) X
;; Setup Procedures ;;
2 g5 o; L& Q- j;;;;;;;;;;;;;;;;;;;;;;: H: h, ?, x0 d1 ~" C& q( R
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;; Initialize the display by giving the global and patch variables initial values.
3 a. Y9 w3 o4 ]2 O- G+ ~( L- e;; Create num-cars of turtles if there are enough road patches for one turtle to# U" G! |0 [7 S7 v) w( Q" e4 ?( g8 @
;; be created per road patch. Set up the plots.5 z8 P2 ` P7 @, I6 y* t* y5 F# J' U
to setup
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setup-globals* d% g3 o {! V8 P
, E6 o4 X# u& n4 g. Y! ^" G A ;; First we ask the patches to draw themselves and set up a few variables9 a0 J3 }8 z, Q, Q. G' @
setup-patches# P# e0 x1 P) \0 F7 {' n/ g! H1 S
make-current one-of intersections
: o" O; m+ e$ k$ N2 T: v9 { label-current1 f) W3 u2 O0 u/ N
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set-default-shape turtles "car"
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: P7 m( _+ D4 N( r* g if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
0 k+ w, ~# |. Y1 T" V "road. Either increase the amount of roads "3 ]! d7 A$ R$ m' ^: s
"by increasing the GRID-SIZE-X or "
( D x# J: @; P6 j e2 H4 K "GRID-SIZE-Y sliders, or decrease the "2 y$ N; \8 y- \) W3 v- s
"number of cars by lowering the NUMBER slider.\n"
2 J P% r6 K$ z "The setup has stopped.") c m. q- Y- g; A) K
stop; s; V A# d1 I0 m- |) t0 S5 p
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color% H4 \+ e: @% ^( B9 [/ p
crt num-cars
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( f' n9 L4 `* y! U3 m" Z setup-cars
' z' T% `' G+ V& ` set-car-color4 k0 l8 [4 r' j
record-data% }- Z1 ~' z5 @- `( d0 T( u
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# c* |5 X7 p J3 }' Q ;; give the turtles an initial speed" Y9 i: ^0 K. ]( g( Y
ask turtles [ set-car-speed ]
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: o% }9 C5 @5 D reset-ticks( Z" T( M! ?- V
end
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" G7 I! M( N! D3 y1 ~;; Initialize the global variables to appropriate values
6 S6 H Y! S& j3 ^- z& Dto setup-globals/ ?0 C7 N' z; z$ g/ W+ y9 c
set current-light nobody ;; just for now, since there are no lights yet2 K6 q3 K1 g3 N4 n* r4 A& P# E# b
set phase 0
# v; P/ K# O$ [) e set num-cars-stopped 0/ i; K+ R; s) S6 a' t& P0 F
set grid-x-inc world-width / grid-size-x: G6 k) r4 y$ ~' W- r \
set grid-y-inc world-height / grid-size-y
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" ^. q2 K5 O8 J* B ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
6 o9 D( F ^( P( e) c0 J set acceleration 0.099
" X( H9 ?) N- I% b( Nend0 s6 v& ]1 k( g$ @3 p% P
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,1 f: \$ b$ H4 i2 @7 L
;; and initialize the traffic lights to one setting
H; b. |. k- [5 a% i- a) h* Mto setup-patches
. h" k% S& x& x' C ;; initialize the patch-owned variables and color the patches to a base-color5 J# q8 H) {4 g j+ M0 z4 _
ask patches' P, u/ S4 ], A) f. W
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set intersection? false
8 S% k( a: L# F. w- M9 E `# j- h set auto? false
5 h3 K6 l9 m4 k$ g set green-light-up? true
) @8 y1 W- {8 P) ]0 i& v6 i P set my-row -17 r1 j$ D @, U3 `" B
set my-column -1
! O0 k1 R' k; x# Q9 A set my-phase -11 j) b( b' u) W# C4 m9 {* N/ `
set pcolor brown + 3! s& R7 |, o/ W5 A, D" o! {1 i
]
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;; initialize the global variables that hold patch agentsets q! l6 d9 v. W/ R* ?
set roads patches with3 @, s) b: N; @6 o) e* G
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 F% a( h3 u/ a# `0 N0 F7 } (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) f" W: G% A0 P: M set intersections roads with! `- a& _! c$ K$ i; f" i
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
. M2 L3 q+ A% d6 ^% { (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: o2 E8 C) U# s' m2 x3 _% W4 @6 {
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ask roads [ set pcolor white ]
2 G7 v/ v( A# o0 B0 Z0 W setup-intersections; |* f2 a t/ ~' r
end
7 P6 o9 q8 {& e* f5 ~+ q6 l) B其中定义道路的句子,如下所示,是什么意思啊?. V/ l1 F: a8 v! m. _- k
set roads patches with
% J4 y' v1 m2 `+ e; O J0 k# O [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" g1 `3 A9 P5 E) W4 P$ q5 k
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ m0 P. _* b1 ^3 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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