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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 w+ W! |, K4 i1 Q" p0 p% u* j. M
netlogo自带的social science--traffic grid这一例子当中,( a6 c0 c, o* O
globals0 [: ~$ O! @$ F B: C8 \) g
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grid-x-inc ;; the amount of patches in between two roads in the x direction
3 d) t5 b0 z1 C1 H grid-y-inc ;; the amount of patches in between two roads in the y direction3 h3 f% I6 \5 y6 `4 d8 W; R* E
acceleration ;; the constant that controls how much a car speeds up or slows down by if# I$ {4 S8 [/ \5 m' I
;; it is to accelerate or decelerate
# K7 t" u/ Q0 x4 ?4 U# x0 ] phase ;; keeps track of the phase& i" y( m* S! z" w1 p
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
7 B( o8 Q' x2 \! j8 | current-light ;; the currently selected light
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;; patch agentsets
) ~/ L/ g3 V2 T+ \ intersections ;; agentset containing the patches that are intersections
8 l$ B' Y: ]5 c& z, L, p roads ;; agentset containing the patches that are roads
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8 U: g. U9 C# pturtles-own( G( `) G" O/ n( ^3 [9 b$ E: t3 A
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speed ;; the speed of the turtle
" D+ [' ?+ I) V3 u5 }8 _* q9 N up-car? ;; true if the turtle moves downwards and false if it moves to the right
5 }. S* j( @/ p. ?2 J wait-time ;; the amount of time since the last time a turtle has moved0 r) F! V5 U& [% a0 c+ b
]
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8 j6 `& i* r) j7 Cpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
4 A, \# @3 x# G: f9 @# N2 v* b1 r green-light-up? ;; true if the green light is above the intersection. otherwise, false.0 D% T+ [" @: h" A7 U( |4 [$ X4 Q* g
;; false for a non-intersection patches.
# _! {) t+ G) f- ` my-row ;; the row of the intersection counting from the upper left corner of the
" l- H" }3 K8 I9 S ;; world. -1 for non-intersection patches.
' I/ F/ Z; Z. s3 W1 `. m my-column ;; the column of the intersection counting from the upper left corner of the
7 L* F3 x# g' y8 { ;; world. -1 for non-intersection patches.- h3 Q) E% A. J6 T, _$ x
my-phase ;; the phase for the intersection. -1 for non-intersection patches.9 D# g$ [: E0 A6 J7 i9 l/ T x, g
auto? ;; whether or not this intersection will switch automatically.
6 }6 B% W! Q) Y) S, I ;; false for non-intersection patches.# m3 d& u* k/ o8 u9 i5 l# @, Z3 D
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;;;;;;;;;;;;;;;;;;;;;;
6 F+ j/ t. O9 ^* J u" h;; Setup Procedures ;;
1 g4 S& ^. Q4 t3 W' W;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values., \, H/ T6 q7 V$ M3 f
;; Create num-cars of turtles if there are enough road patches for one turtle to
/ N3 e* z0 P& }. Z, k( V8 V;; be created per road patch. Set up the plots.. w0 u9 ]8 _5 T& S# e, G
to setup% {9 ^3 a7 |- {8 ^) D3 t ^1 @
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setup-globals2 ~) Q3 R; ?8 Q9 \" A/ w" F& G3 ~
2 C: h& P$ k$ ?) w L* p0 B% A ;; First we ask the patches to draw themselves and set up a few variables
, l$ v; j( M5 d setup-patches
0 o- R7 x+ Q3 w+ q make-current one-of intersections& ?4 f, D" d$ s6 s- g: e: |) N* K
label-current
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" r+ t5 N3 s) r- b set-default-shape turtles "car", O- F, d8 W% R/ e3 @ i9 y
6 E) z1 k) ^' ^, X6 \ if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of ", d2 e' e7 m9 k9 @ X7 E
"road. Either increase the amount of roads "
0 p G2 e. t/ N# l7 u% r; v "by increasing the GRID-SIZE-X or "& i* |" D$ G0 g0 E% O* |
"GRID-SIZE-Y sliders, or decrease the "% M3 p' q$ r, J8 A
"number of cars by lowering the NUMBER slider.\n"' W2 v# @1 r% ^2 ~- P
"The setup has stopped.")- T3 Y; y- \5 e: r' E0 H! q4 _7 J
stop
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0 y4 w6 j$ V: C0 h" I" K2 A ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color" p4 j) l3 T8 P8 I
crt num-cars5 u4 r& x& V, ^3 a( A5 [
[
0 ^/ w8 q) W; Q: D setup-cars
& t3 {0 x8 e5 {# s k6 V' f/ a set-car-color
5 j' J* L. ?6 i4 n record-data& C* |# R0 l: k9 M/ B
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;; give the turtles an initial speed, g5 x; a8 E4 T9 ^
ask turtles [ set-car-speed ]
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reset-ticks, ~9 W/ o6 ~2 I$ d% _6 F
end
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;; Initialize the global variables to appropriate values, }) u( \1 c# Y% D1 C5 ]$ B% D3 ^
to setup-globals3 e0 |9 ?6 A. B
set current-light nobody ;; just for now, since there are no lights yet
1 U$ F3 \8 J8 ] set phase 06 G/ U2 O& a1 m+ u1 h$ i0 [/ t5 V
set num-cars-stopped 06 J2 A* g- T3 o% q" \$ [
set grid-x-inc world-width / grid-size-x1 s0 Q J/ j0 `) |
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
8 }- v3 N9 x! u3 D# i set acceleration 0.0994 J6 f9 Q# y% M! V
end
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* j4 L0 B8 k3 u- c9 C& C;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
$ |$ K5 l# {) E4 H# U; i L;; and initialize the traffic lights to one setting; ?! O0 \/ Q; t3 a+ c2 X/ y8 _" m
to setup-patches
: o6 I1 F5 v- ^3 _, T ;; initialize the patch-owned variables and color the patches to a base-color
2 S% y+ F7 I! f* y+ r ask patches
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set intersection? false4 @9 k& F0 B u) v9 ~( g3 E3 a
set auto? false( ~! P6 e! W# C# |- |
set green-light-up? true
2 e2 K/ a# ?+ A( ]: p8 H set my-row -1
1 {! M. e) o8 ~' N set my-column -1$ k# A9 N1 r. ^* j
set my-phase -1
! h% D2 I; i/ E. Q" x+ l set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets' J7 y8 W2 a# ^( y* d1 S
set roads patches with$ O, T2 p6 r/ N7 L
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" i) c R# j# x1 i- _/ U% z" P* Q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ }: G/ y8 E. h$ O: I! I
set intersections roads with
, p4 g" A C) u( t3 [ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
) m- i6 M' o* u$ q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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: | n8 h) D9 l! X: b9 F ask roads [ set pcolor white ]0 _# W4 o1 }/ V. X
setup-intersections( T' {2 C: D6 f/ t5 q8 ?( l: [ S% H
end- A6 K1 r0 {+ x( M( a/ o# Z
其中定义道路的句子,如下所示,是什么意思啊?* ]% I" T5 l) p4 ~0 D4 r! ]1 D6 N
set roads patches with- Z& b6 Y2 B/ T2 l5 a( C
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 m7 i7 n, ~! v2 I [1 P2 H; C$ q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
e7 m* W) X- N' d( t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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