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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。& j8 v% d/ v6 x" i& C
netlogo自带的social science--traffic grid这一例子当中,$ A& h* F+ r% e$ B$ N# ~) P. D: H3 ?
globals$ P4 e! H$ N z' ]( k* r1 K
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grid-x-inc ;; the amount of patches in between two roads in the x direction1 U* f0 f0 u6 H0 e
grid-y-inc ;; the amount of patches in between two roads in the y direction
; u+ q3 ]9 P' k* q acceleration ;; the constant that controls how much a car speeds up or slows down by if" ?/ }, J+ O' l- ~2 R. |
;; it is to accelerate or decelerate% N! y( \' p$ F$ i9 @4 w, u/ V
phase ;; keeps track of the phase
1 y2 P2 h; p' a0 F! w num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure3 H+ F4 b7 B' U: e& n, s3 E
current-light ;; the currently selected light6 {8 _0 ^0 X) U1 Y8 l: \9 s% S
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;; patch agentsets* ~: T( O% Z2 _* P3 P
intersections ;; agentset containing the patches that are intersections1 z- p8 F- O) e# \6 y9 l
roads ;; agentset containing the patches that are roads
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: G7 x" m* c7 V* T' _& `$ Nturtles-own7 r. P3 S" O) Z
[
# U& W0 C" i- T5 u8 T$ l speed ;; the speed of the turtle
W; V' P4 i7 M4 F up-car? ;; true if the turtle moves downwards and false if it moves to the right8 J3 p3 X# M9 u) `9 H# J" r
wait-time ;; the amount of time since the last time a turtle has moved) m! U4 ~9 A j" g0 Z( ~+ m9 q
]
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- A9 Y) j1 `4 b' kpatches-own
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, c3 K! }9 x0 V4 Z intersection? ;; true if the patch is at the intersection of two roads; r6 S" |# e5 w& h; F
green-light-up? ;; true if the green light is above the intersection. otherwise, false.3 t! w6 p1 P" J# \8 H
;; false for a non-intersection patches.
1 ?2 g* t% b/ Y) d6 ~ my-row ;; the row of the intersection counting from the upper left corner of the9 j% p+ a2 u1 ~
;; world. -1 for non-intersection patches.2 ]. e* H% b O# v0 L2 m L
my-column ;; the column of the intersection counting from the upper left corner of the
1 y* a& t9 ]# C ;; world. -1 for non-intersection patches.
, X+ [, Z* y& g my-phase ;; the phase for the intersection. -1 for non-intersection patches.# V8 C# {7 ^$ L0 q- f
auto? ;; whether or not this intersection will switch automatically.0 ]) q6 o2 z6 y/ Z* X
;; false for non-intersection patches.# |( h; z; z" d! @0 e2 L; }
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6 Y! I- j# `$ s" s x;;;;;;;;;;;;;;;;;;;;;;5 U, D. ^$ i& ]- e9 Z
;; Setup Procedures ;;
# \6 s9 m, v' Z& i* y# O. k/ k;;;;;;;;;;;;;;;;;;;;;;
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( J9 ^ n* c4 Z( ~6 ^;; Initialize the display by giving the global and patch variables initial values.
0 A7 u" e! a& A8 j) q7 a* l;; Create num-cars of turtles if there are enough road patches for one turtle to
1 Y7 U0 u8 [4 G" ~3 x* b- T5 g( ];; be created per road patch. Set up the plots.
8 f8 R7 ^* Q; ~1 ?( v; x1 [3 t4 ^to setup/ U q3 e- J; n- P# T
ca
) a: @0 s4 g: ^7 n5 R setup-globals
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;; First we ask the patches to draw themselves and set up a few variables) B/ @5 }5 }6 a6 }" m- Y2 Y
setup-patches( a' U6 G v6 I0 H6 U) X1 s2 y
make-current one-of intersections
$ @5 `& V& n* d label-current
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set-default-shape turtles "car"
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- \. t. D% g$ S. S/ S6 h* \5 q, J if (num-cars > count roads)4 G; ]0 w" r/ M6 X. M; m* u& f
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0 T0 d# p3 U9 c% x& S; U! O$ l" g user-message (word "There are too many cars for the amount of "
2 U; [$ e7 h' ~: { "road. Either increase the amount of roads "
! g7 a$ c0 V( i! ^0 q' M1 t "by increasing the GRID-SIZE-X or "
; p1 r9 `0 e# J3 p "GRID-SIZE-Y sliders, or decrease the "
5 d5 t1 u3 z! m' Y- b$ Z- k5 O& z2 ? "number of cars by lowering the NUMBER slider.\n"& I) z& }& p9 K6 m
"The setup has stopped.")
6 l4 Z* |( R# C, s# i stop1 C" t) {, A/ D# }
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
# t1 R/ q3 p; ?5 G: E2 M* v crt num-cars
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! ], V) j* q/ s' w" c" r; |4 O# H setup-cars
. U+ D5 i# _# ` set-car-color8 }+ Y6 J# v( A& }
record-data( Q9 M) ?# J; g5 d( E0 g& L
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6 p9 ] H! s/ G% P ;; give the turtles an initial speed
6 u& m( J& y: u3 r5 w" t ask turtles [ set-car-speed ]) k8 I1 \& B4 q, \, L4 m
- p3 i- [; K# f8 F0 e: z reset-ticks( R0 A5 J/ |2 N5 c% T7 Z
end' g0 f5 I8 n7 O# k$ D" ?
$ a1 F: d' w `( | F% u;; Initialize the global variables to appropriate values6 Y% e* k) C5 B$ l7 d0 D" B* G
to setup-globals* E, N7 {1 y i8 x5 j
set current-light nobody ;; just for now, since there are no lights yet
6 m P: K" l0 x, |' ^# j set phase 0
% o3 o8 W1 M, B' y2 u set num-cars-stopped 0& x1 Y U+ w1 h! s
set grid-x-inc world-width / grid-size-x4 l4 a1 v9 r% q
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% z; q+ y1 z9 b, t" G
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,! G7 _6 e2 ?! j" ^
;; and initialize the traffic lights to one setting0 Z+ |8 q- T* o, U% n" g
to setup-patches
0 r( f, ^1 t F ;; initialize the patch-owned variables and color the patches to a base-color' T- {5 c/ D# B
ask patches& x: l) G3 ?+ ?" k3 K" Z7 u/ W! u
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- h9 R5 B, o" P+ f+ V- M5 ] set intersection? false
# {1 T$ A+ i% j1 b6 @: N& a set auto? false
0 V9 W7 {; X5 ^6 H# t8 q: ` set green-light-up? true9 Y" O+ A8 J4 }* t; e
set my-row -1
- ^( W, {) B& V set my-column -1, q' v3 Y5 w' N
set my-phase -1% Y2 l9 Y6 Z7 E! J. u7 g! D& d
set pcolor brown + 3! ]3 n) W+ {" r: J5 ?
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: c% D0 J' B. L: b, X1 s' c3 Y ;; initialize the global variables that hold patch agentsets8 R! p& L8 Z; C5 P1 V' h* |
set roads patches with0 B0 F/ D" O1 c8 J
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' ^9 E6 g: t4 ~* I4 y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" e( p# |! \& n8 O, M: v) n set intersections roads with
. s( _; p) r& Z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
3 s( }( P; ?" P/ u (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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! e0 R( p% W& ~& E* t ask roads [ set pcolor white ]
( D. h, k; {. ]% U setup-intersections5 E+ g5 i9 k6 P" s/ s2 ^
end& e2 v& [. M( M' D+ `% ~8 o! X3 n
其中定义道路的句子,如下所示,是什么意思啊?" P/ I; G- _* }& o/ H- K+ A! ]+ Y( g. b
set roads patches with
' | W' s4 S- ^: z% a$ G [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or6 f+ e, L" b: {1 Z4 q* n
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 J" O/ l0 Q; Y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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