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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。6 C3 f/ T6 G# O
netlogo自带的social science--traffic grid这一例子当中,
/ b" ]6 V; u7 u, Mglobals" _, J7 d& h1 |+ _3 P5 ?
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2 v3 `7 [. B! ` grid-x-inc ;; the amount of patches in between two roads in the x direction
0 J. S. R& U. C. M5 K grid-y-inc ;; the amount of patches in between two roads in the y direction
3 e6 H k& e( \; ?) `/ C; n acceleration ;; the constant that controls how much a car speeds up or slows down by if
5 B9 A* e( x+ y/ P, f- v ;; it is to accelerate or decelerate
. k" |( o- s6 s0 I# H/ c$ L phase ;; keeps track of the phase7 G! D# S) k2 K
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
! b) @$ H9 b U% h3 v, k, d, ] current-light ;; the currently selected light
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" G$ h4 f0 n! K3 L2 Z ;; patch agentsets
( |1 q+ L0 p8 N b, K$ m intersections ;; agentset containing the patches that are intersections
( _8 v- h4 ^/ k" |: H roads ;; agentset containing the patches that are roads, o* F+ x, O( J" y+ |9 N: U& C
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turtles-own
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speed ;; the speed of the turtle1 @- s1 B) N+ V! |
up-car? ;; true if the turtle moves downwards and false if it moves to the right) B0 }$ c( E8 P; L3 H
wait-time ;; the amount of time since the last time a turtle has moved, a$ f7 A4 ]- z. z( M) q
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+ \% y; s( H( Ppatches-own
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intersection? ;; true if the patch is at the intersection of two roads
) C; u# O6 P" ^" |* M f5 S b7 } green-light-up? ;; true if the green light is above the intersection. otherwise, false.
* K4 i4 t3 Q z+ N- q# L& H* @ ;; false for a non-intersection patches./ z+ Z4 O# g- S# ~2 C' n
my-row ;; the row of the intersection counting from the upper left corner of the2 l$ C: H) ^- A3 G# C7 X0 y1 P
;; world. -1 for non-intersection patches.
/ ?( W$ g% J& }% [! c my-column ;; the column of the intersection counting from the upper left corner of the
$ }5 B$ _+ B: x7 J8 D ;; world. -1 for non-intersection patches.6 @9 [: H# t% Y
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
0 J6 q ?+ l. K" i0 U auto? ;; whether or not this intersection will switch automatically.
. p/ w ^, f+ C, M2 E* i( C1 V+ k ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
- H; q1 ~3 p% {( T6 c9 X;; Setup Procedures ;;
0 e4 h4 ~4 ?2 R& ];;;;;;;;;;;;;;;;;;;;;;
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/ S' ^: b. Z+ j- W( a;; Initialize the display by giving the global and patch variables initial values.
# n8 J2 g4 k: k' |3 d/ s/ \;; Create num-cars of turtles if there are enough road patches for one turtle to
; I5 v2 V5 t7 j- g; Y;; be created per road patch. Set up the plots.8 n8 H* S0 z1 f% q
to setup
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4 _( j' g0 L7 ` setup-globals5 {% M# ?& h8 x0 Z
4 U! |( c; ?. o7 N ;; First we ask the patches to draw themselves and set up a few variables/ H- G1 |. o5 }) t! I
setup-patches
$ N. e/ P! `* J- f3 W make-current one-of intersections n- P2 u5 `; L l: E
label-current' B# Y: U. s+ M. N& i" v- I
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set-default-shape turtles "car") H; @ q1 O2 w) t7 s
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if (num-cars > count roads)! e" Q' D a/ `: N- e6 I# k# Z
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( ]6 w( C# l' Q; S( F. S* k user-message (word "There are too many cars for the amount of "
4 Q( ~! \- k6 ?9 a' K3 \ "road. Either increase the amount of roads "
& V; g7 D5 u9 T9 |% _+ c) I: G4 i "by increasing the GRID-SIZE-X or "' L3 G) \3 f! R
"GRID-SIZE-Y sliders, or decrease the "
! @6 T9 |- m0 l" |; ?: M "number of cars by lowering the NUMBER slider.\n"& y" y4 E4 A/ g# f! x1 [7 o
"The setup has stopped.")6 c+ g, ]& D- `/ g6 O( s2 A
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
\3 Q; b& T2 s( j" Z) m% j crt num-cars
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setup-cars b7 ~: _+ r9 M: c( h r
set-car-color
" X4 h, o6 v9 D/ ?, [; M5 x a record-data& f0 D0 \+ u8 D& M# D$ P
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/ _, ?# @: o. S- } ;; give the turtles an initial speed2 Y C3 Z2 R) o
ask turtles [ set-car-speed ]
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reset-ticks
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;; Initialize the global variables to appropriate values
8 O/ f: T m5 R2 u+ r, N/ ito setup-globals
3 _& E; ~. h& b+ e! t set current-light nobody ;; just for now, since there are no lights yet
# Z, j1 S3 Q9 Q+ ]; b set phase 0- U, O1 B, z- i9 w" {
set num-cars-stopped 07 i' ~4 V x6 M9 S7 ?
set grid-x-inc world-width / grid-size-x" P$ N+ f5 Y9 e2 O$ U! b7 p
set grid-y-inc world-height / grid-size-y3 P" @% N3 w5 i! u6 o) v
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
$ ^# E/ h% p+ H$ H( L set acceleration 0.099
& @8 N( r1 J$ e; j! K8 rend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,& b: G$ e- z( W
;; and initialize the traffic lights to one setting9 A5 K" ~) t; Z) |, Z
to setup-patches) x* J) `1 |& Q
;; initialize the patch-owned variables and color the patches to a base-color1 o5 P. M+ k3 r! @4 q
ask patches
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set intersection? false2 t& {& R% G3 G* g, P" p2 K
set auto? false/ M. s" k9 ?% k0 U! R3 M& s" [1 r
set green-light-up? true
) R4 _1 A- z5 R- n set my-row -1
0 d9 X( e" K+ K2 L; c' _( o7 p set my-column -1- v0 e( j4 g7 F7 t3 Z; {( s
set my-phase -19 c, Y- \' |" V6 N6 V, U
set pcolor brown + 3
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0 W& e+ k& J+ r1 S% B ;; initialize the global variables that hold patch agentsets! h' Q" r4 W. P& }( J# J
set roads patches with" d9 [* j4 E" Y& y% } X
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or0 E( D* g- c8 `# ~/ L) F4 M
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* l' H: j/ m' T set intersections roads with
( \/ ]8 ?- F8 z, w7 b+ m [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
9 v; ^/ F( T: k1 c+ m (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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8 r6 l& b- C' V9 \/ s. P2 o9 P9 E ask roads [ set pcolor white ]( L5 I! ^" P3 L# {! w4 R( i% P
setup-intersections
2 E6 j( B R+ n' ]7 @) a% Dend
0 h* X5 `( D, c, {其中定义道路的句子,如下所示,是什么意思啊?% |. [% Y" o5 Q. A$ F- d
set roads patches with# J5 b3 u7 ~' G, X
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or8 l7 S7 w" B' F" g4 g+ Z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 ^) P2 q! k4 y1 H* ]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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