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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。
1 z0 K: o4 \- {8 E+ Y: _" Snetlogo自带的social science--traffic grid这一例子当中,
+ a- }0 I$ s8 S- @0 d1 gglobals
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f7 ]4 U+ Y! C1 } grid-x-inc ;; the amount of patches in between two roads in the x direction, w3 V# O- k, J A! I6 n3 l
grid-y-inc ;; the amount of patches in between two roads in the y direction/ ~4 }5 y$ H+ j- H4 s
acceleration ;; the constant that controls how much a car speeds up or slows down by if
* d6 T5 Y: _% x+ P% I* H" ^ ;; it is to accelerate or decelerate
- C. X( m: r: x& k, o/ ` phase ;; keeps track of the phase" A# h. x$ W( a! n7 |" G6 Z
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
7 H+ u9 Y* S$ a6 M current-light ;; the currently selected light
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: `" I9 D( T) ~. u: \: [. H, u7 u ;; patch agentsets
1 r' [3 ~) F6 J. a2 \ intersections ;; agentset containing the patches that are intersections
/ @6 Y9 i$ g1 R2 N. l# Y roads ;; agentset containing the patches that are roads
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turtles-own
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. z" a" f1 r4 E2 m+ n4 n3 l speed ;; the speed of the turtle& [- S/ u, G& P# | C3 i% m
up-car? ;; true if the turtle moves downwards and false if it moves to the right
! V1 K# ~0 E# G+ P @0 b wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads8 ?; s3 g" A0 F% v- x% _' ?. T
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
3 i. R1 z1 e+ N' I: O1 \ ;; false for a non-intersection patches.$ G: j3 w9 M: r, M; ?8 R
my-row ;; the row of the intersection counting from the upper left corner of the l: ]' }: b) q3 x
;; world. -1 for non-intersection patches.
8 `& U; s# w7 a$ V B: q. |) D my-column ;; the column of the intersection counting from the upper left corner of the& s0 J+ v+ N6 ~! G$ X# t
;; world. -1 for non-intersection patches.
/ i( [- k7 q) I! o my-phase ;; the phase for the intersection. -1 for non-intersection patches.( l' Y _9 u; ~8 f; u7 T! E
auto? ;; whether or not this intersection will switch automatically.) b+ H7 k+ E7 b% ~ E
;; false for non-intersection patches.
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! ^$ |& c# x, c* W4 Z G;;;;;;;;;;;;;;;;;;;;;;* _* X% [& C) V; f# i) p+ w3 N
;; Setup Procedures ;;
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' [9 c* l- B# V' [' e- r4 [2 I;; Initialize the display by giving the global and patch variables initial values.5 @, \7 }/ w+ N C2 _. q, c
;; Create num-cars of turtles if there are enough road patches for one turtle to
! E( {2 [* n2 O0 l;; be created per road patch. Set up the plots.
) T* X( e: S, P/ |+ c, q7 ito setup
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1 \* |. J: c9 U- e* Z setup-globals: e7 ~ @. m! ~" [* K- ^" Q
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;; First we ask the patches to draw themselves and set up a few variables
0 K$ z9 V: X: z setup-patches
c" P) l$ J9 C& P4 p- U make-current one-of intersections: A& i2 t- Z9 Q9 _) ?/ S+ ~
label-current6 s/ w) l1 z5 T) M) I, U
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set-default-shape turtles "car"
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% O4 l- p2 p% \8 g- k4 W if (num-cars > count roads)
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" j2 Q; r: _1 r% u+ |/ g. ~ user-message (word "There are too many cars for the amount of "3 s# c E z# }% Y* L
"road. Either increase the amount of roads "
. P+ p* l2 v- Z7 @/ O$ h/ j6 C2 p "by increasing the GRID-SIZE-X or "4 J* E9 @9 `2 o- p; ?, P$ E: m
"GRID-SIZE-Y sliders, or decrease the ". K/ R" J8 s2 ^2 S; c* b
"number of cars by lowering the NUMBER slider.\n"
2 i1 f' r" v/ h0 e6 u1 } "The setup has stopped.")
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]
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
# a7 X1 h# ~1 W4 @- i9 |: ]6 j crt num-cars
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- Z8 h1 X# m, q5 H) _ setup-cars, q5 v, a6 t9 _. y p
set-car-color) D p9 Y6 D' p4 f* T- R [4 @
record-data' X7 C6 ?& w# v: A
]
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& d. q. [( W. t, r9 P" x4 Y ;; give the turtles an initial speed
9 c$ U3 t- ^2 k; K4 H ask turtles [ set-car-speed ]
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. q4 H; B7 S8 g6 P6 u2 W reset-ticks" _) N* _* h1 L- r
end
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;; Initialize the global variables to appropriate values
# y' ]6 `' p' Tto setup-globals
# }: q8 q! V" Q& d set current-light nobody ;; just for now, since there are no lights yet h, Z7 ] ?0 X0 s
set phase 0
$ L0 h7 @2 k1 ^* M( b- u set num-cars-stopped 0
6 s* `( I4 O" F" A set grid-x-inc world-width / grid-size-x
}6 o( F& g& a M7 d6 K set grid-y-inc world-height / grid-size-y; J3 d" j$ _) K, `" g
N \6 R7 H) a7 N! w" R ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary* H; l/ ^0 ]/ ?. y
set acceleration 0.099
4 w8 d" J- a8 H% J- z6 e# y2 jend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
( }0 O& \: J, S; d( L2 T;; and initialize the traffic lights to one setting
5 I- A b8 s( M9 O7 |" h' Zto setup-patches
) u% s+ j3 c- \6 V* D# q ;; initialize the patch-owned variables and color the patches to a base-color
( K! g, ], P, i1 s* `9 F ask patches
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, ]6 D+ f2 K; |6 @; P$ S" R& y set intersection? false
$ Y' p- J3 t. k8 ~& t- C# g8 r set auto? false
, o1 Z- H+ w/ Y( \: a' I( J8 s set green-light-up? true
7 T0 I% p8 k9 Y' t) q, f ^, t set my-row -1
& ]3 n9 [& e b0 }" ?# J( e. Y) e; g set my-column -1: N! z3 Q- p! B3 n8 {! }% c
set my-phase -1
# M3 j' w! Q/ U2 U0 h set pcolor brown + 3
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/ l. B2 G- Z0 s L ;; initialize the global variables that hold patch agentsets
1 G% c& D2 M8 r1 x& t! f* b set roads patches with
4 @, a6 O* c0 L0 Y7 c" r7 |* F* ~ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 m9 H3 [7 b$ V (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
& r# @0 Q" n$ u; b' Q# Q set intersections roads with
+ D2 r6 u7 [; u) |5 L* a! h6 j+ Q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
! h, z: |' z( ]. m( v1 \& i (floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 P4 |7 h# A1 r# U! N! w$ i( r
/ z1 Z Z2 G7 J! D' q ask roads [ set pcolor white ]
/ h4 l8 n1 X0 } N1 e setup-intersections
9 S( d6 h/ I/ E. n f+ O! Yend" Z* _& ~/ n: L- U
其中定义道路的句子,如下所示,是什么意思啊?
: o4 X8 S3 v; y- t: v set roads patches with
7 Z2 m4 ~8 U, \* J' z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
- l1 u2 ? }8 h: G/ ^ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" C& b% e0 u* v5 H \# f1 K# v0 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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