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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。+ Q) |; s' G& p) Y
netlogo自带的social science--traffic grid这一例子当中,4 F, ?+ g! l" i! G' R f8 y
globals
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6 ~/ E2 W7 H, t/ E7 ~ grid-x-inc ;; the amount of patches in between two roads in the x direction
b- M# A; E1 A9 | grid-y-inc ;; the amount of patches in between two roads in the y direction
; O" C! S7 A- \; W5 X0 o; r acceleration ;; the constant that controls how much a car speeds up or slows down by if) O( {+ Q- w3 f
;; it is to accelerate or decelerate: \: \7 G( R1 l2 M4 @8 A: ^
phase ;; keeps track of the phase
' o# @: M x% K" F, A6 r num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
Z# V Y3 K' `5 T current-light ;; the currently selected light1 } l/ a- X: h, U% b( h
* J" Z/ i& w! w% [7 V# ^ ;; patch agentsets
, Y& w$ L/ C- s3 G" f! M) S( Q9 ` intersections ;; agentset containing the patches that are intersections
. _% I3 [/ b1 {; i roads ;; agentset containing the patches that are roads" ]8 b. O3 q; ?0 o2 r7 l' O
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turtles-own' y6 x% U7 G# N; D5 |8 H
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speed ;; the speed of the turtle
$ K1 K4 E( f! q4 l/ n3 V up-car? ;; true if the turtle moves downwards and false if it moves to the right
8 J1 w4 m" p1 E) d/ {% o wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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$ g; ?2 B6 N9 z9 W, ~* W) Q intersection? ;; true if the patch is at the intersection of two roads
2 U! O% a8 j- x. p; h, t5 _ green-light-up? ;; true if the green light is above the intersection. otherwise, false.0 M) \* y/ t' t% d2 B) b. m& Z* Z
;; false for a non-intersection patches.
: [* y+ a2 r. S5 _- q my-row ;; the row of the intersection counting from the upper left corner of the% _% i$ B/ U: ^6 j- O4 y+ V3 i
;; world. -1 for non-intersection patches.1 L( A$ ~) }- U" X: Q
my-column ;; the column of the intersection counting from the upper left corner of the
. e9 `7 T5 Z. @ ;; world. -1 for non-intersection patches.6 O! O8 e1 Y* @4 G, o; x0 z- D
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
. u4 p: M k0 u- y# \ auto? ;; whether or not this intersection will switch automatically.
7 z. ? E. F. F# p" R ;; false for non-intersection patches.% Q" L- |. d$ a4 A( L& L% T
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;;;;;;;;;;;;;;;;;;;;;;
, [- T2 B& |) z o;; Setup Procedures ;;
' \- |$ R0 H" `) T$ e0 [- D* S;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
+ p, S+ j$ r- N! s" s;; Create num-cars of turtles if there are enough road patches for one turtle to
3 b; h8 [# @7 i6 f+ b4 k* S;; be created per road patch. Set up the plots.
" z2 R4 j* d% D) A1 w6 U1 _4 mto setup
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setup-globals$ B- Z/ z1 @/ v! t% E& c
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;; First we ask the patches to draw themselves and set up a few variables: Q8 k8 {% e x2 o! Q
setup-patches# y+ d0 u- x- h0 [: S/ E
make-current one-of intersections
$ [% O4 f) \. h6 L9 E6 B& P label-current
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set-default-shape turtles "car"
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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 "
+ Z/ g' { q$ w5 x "road. Either increase the amount of roads "
& `; t) H# I1 c& f2 ]: d5 l "by increasing the GRID-SIZE-X or "! s8 N8 M; Z; N: v/ v; z: e
"GRID-SIZE-Y sliders, or decrease the "9 F9 T, W, M$ V# e. X
"number of cars by lowering the NUMBER slider.\n"" x9 Z4 T3 D, T1 F
"The setup has stopped.")! F- c3 O7 P' l3 i; r! \
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
/ f' i& R3 o) l. Y crt num-cars
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setup-cars7 m9 o$ K: O8 @& J4 A0 i4 }
set-car-color
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;; give the turtles an initial speed% D- K% F* E6 D4 t
ask turtles [ set-car-speed ]" g' n( J* T/ I, t- ], E
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reset-ticks$ i. g* V8 x* j$ q6 [' {- E
end
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' h+ M& E' z, s5 F& F# };; Initialize the global variables to appropriate values4 n2 d$ G. b3 O7 ]7 D; @) I, K
to setup-globals
9 ~0 R" V4 D, k$ p* r set current-light nobody ;; just for now, since there are no lights yet
' [, _) y- e4 n set phase 0; ^+ d# P: C( w5 [
set num-cars-stopped 0
c; s; |* }9 V% o/ G1 h set grid-x-inc world-width / grid-size-x
" D' n' x; P. z0 ~: C' e2 F set grid-y-inc world-height / grid-size-y
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! m' h; [: U1 a ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
1 x1 L* ~( B4 Q# f% _6 V set acceleration 0.099! v+ h) e( B; m: u6 n- k( p+ T7 I
end, U; A. b! S+ o* K
7 U$ h! d5 h$ O) c! ?. l0 E' I7 x;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
) P; \, F6 L* W) K6 Y;; and initialize the traffic lights to one setting5 A( M0 F0 i* @, d# l, b6 z. `
to setup-patches @( i& [3 A! @
;; initialize the patch-owned variables and color the patches to a base-color
# d- c5 N2 ~6 l5 [( S ask patches
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set intersection? false
H2 \ c; B+ E/ y7 P set auto? false
K: M# d' |7 l set green-light-up? true* e0 k- Q$ C1 ]5 q8 ]9 A
set my-row -1
) z, v% x( p0 ~9 g$ V( I set my-column -15 l8 P8 A6 k f( f" C) q# g! k/ }
set my-phase -16 u, U" [' P6 j/ p, N
set pcolor brown + 3* J$ g1 I/ S* s
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;; initialize the global variables that hold patch agentsets$ F: R/ \, m6 I) c$ D
set roads patches with
$ R U# V5 q& W, t3 |9 B [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' N( h/ d* [( _$ s- e/ ^- c. z8 m (floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 g" b8 T- z; l* f
set intersections roads with/ V% i7 K* S$ A9 C b: c
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and1 Y& `+ ^" @8 e% ^2 x% c' |
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]! L2 D$ [) f6 q1 m2 P+ P6 b: p
) _, M: O8 r+ g( H( b ask roads [ set pcolor white ]
! J4 l C3 y/ a- ~9 g1 ?$ p setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?+ H6 l+ o" {/ B8 r/ Y
set roads patches with1 ^/ @+ X: r2 d! U6 ^
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, o$ X) \2 `% b# c. u0 I
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* K- a6 P9 z' c& @3 i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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