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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。9 G2 h7 H' |( T8 C, k" F
netlogo自带的social science--traffic grid这一例子当中,
" X }5 j$ g! A& p! oglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
+ A W( {0 t: k# A( ^ grid-y-inc ;; the amount of patches in between two roads in the y direction
; e$ C9 X; J6 {3 V6 t# L% I acceleration ;; the constant that controls how much a car speeds up or slows down by if8 D+ y. R8 u# m* x6 g9 t
;; it is to accelerate or decelerate
8 u. a, _6 Z5 d- L# }/ b phase ;; keeps track of the phase( Q* v* F. a* ~7 Z" b
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure1 C. P$ W( m/ b0 |
current-light ;; the currently selected light x' B3 P: h A) r
/ `5 x/ ]% L2 I( b1 ] ;; patch agentsets0 `# X: y' v z% J
intersections ;; agentset containing the patches that are intersections) m# B& s8 q$ C
roads ;; agentset containing the patches that are roads* p: e. P" m8 g$ k4 V. B9 ?
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! }. [4 J1 ]! L" v, ^. m1 sturtles-own
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# d0 l" m1 F- H: \5 f" `. L1 ? speed ;; the speed of the turtle( l$ K: b5 P, i- [
up-car? ;; true if the turtle moves downwards and false if it moves to the right ~3 U$ i5 B1 |9 l5 j0 Q
wait-time ;; the amount of time since the last time a turtle has moved+ L4 W! v2 r' l
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' Y) y) g6 Y' a( n( n& lpatches-own
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intersection? ;; true if the patch is at the intersection of two roads: a: H6 T# ^# s, r0 }! O1 P9 w! R
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
1 L) O* e9 n' P' i% y: _ ;; false for a non-intersection patches.
6 F: l2 N/ O$ D% a/ t my-row ;; the row of the intersection counting from the upper left corner of the8 k4 |7 I+ P g6 N# x- t( X
;; world. -1 for non-intersection patches.9 n1 O, n# O1 Q9 F% L$ w" B5 W
my-column ;; the column of the intersection counting from the upper left corner of the1 a0 c2 X1 o- V1 D
;; world. -1 for non-intersection patches.
) A' Q' t: }3 Z; u) U O my-phase ;; the phase for the intersection. -1 for non-intersection patches.1 c4 @2 s$ ?, `# {5 ^
auto? ;; whether or not this intersection will switch automatically.
/ Y8 V( |% q; y) ~9 h ;; false for non-intersection patches.8 r' e% Y+ _# v) A; _% y9 j
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;;;;;;;;;;;;;;;;;;;;;;! @; f' Y' f) T0 }( P# g( k x+ B0 g
;; Setup Procedures ;;5 r; W/ ~7 |1 D0 i4 J
;;;;;;;;;;;;;;;;;;;;;;
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2 B* D+ ^4 ?$ ^6 Z- m& L;; Initialize the display by giving the global and patch variables initial values.% j. I( F! M1 c
;; Create num-cars of turtles if there are enough road patches for one turtle to$ r( a% W9 k3 V6 D4 }
;; be created per road patch. Set up the plots.
' z* I3 V0 V9 C8 R" `/ wto setup+ x; y4 [" f0 V+ v# t# Q
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setup-globals
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: D$ }8 H `$ E4 W6 K ;; First we ask the patches to draw themselves and set up a few variables+ O% H E* j- s- M) M: ^- D
setup-patches C* ]0 l, w$ g' I9 l
make-current one-of intersections
0 d9 Q! f1 t7 G& C label-current
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set-default-shape turtles "car"6 N, f8 ]5 U9 B+ B( c
0 ~$ C( H' y6 B" Q if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "6 @) K/ E ^6 J; C D8 x1 H; d
"road. Either increase the amount of roads "2 V! j9 T. ~% O6 b2 J+ B
"by increasing the GRID-SIZE-X or "( l2 O; Z0 q8 h8 [3 d
"GRID-SIZE-Y sliders, or decrease the "
$ ]" I7 Q5 Y. ^3 T# U' Z "number of cars by lowering the NUMBER slider.\n"
/ Y* s1 H% k! r/ O I0 M) ? "The setup has stopped.")
; R0 a p z/ f% j+ ^ stop, E5 e& \$ q4 E5 l2 I
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color7 M4 z# E7 N* Y3 A# ~ E' g
crt num-cars
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1 {3 k. S* X) y. _# g( k setup-cars+ g1 B$ G5 U* C2 c* [& Z4 \' y
set-car-color% D% a: C( G+ O$ h- j% p
record-data A9 k) E) c: ^* w. F
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;; give the turtles an initial speed4 N% S0 l) i! m: F4 r9 l
ask turtles [ set-car-speed ]: T9 K4 Y5 d* v j
) X$ ]( I0 J/ v reset-ticks
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;; Initialize the global variables to appropriate values. L e5 G' b: F- s/ d
to setup-globals
: e/ v" v: n) R! _- G! I5 W8 f9 ?/ O set current-light nobody ;; just for now, since there are no lights yet) B3 p9 t$ h1 o' j
set phase 0. L- j* i* G; B
set num-cars-stopped 0* u1 W; E2 Q# J, w5 }$ u/ i6 i
set grid-x-inc world-width / grid-size-x
a o* v8 W3 o p( @* v6 J" f+ D set grid-y-inc world-height / grid-size-y
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- ^1 ]+ m* F2 Q' x! Y9 m( [& \ ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
/ S% m! b. Y; h set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
. B8 h: {! ^9 z% J;; and initialize the traffic lights to one setting
0 h9 h2 V. ]) Z1 O* V' y% cto setup-patches! u4 ~) p/ z2 Q2 O0 }; ?8 s
;; initialize the patch-owned variables and color the patches to a base-color9 p' x, }5 x" @3 r) b
ask patches& P' K% i/ w& ~" t3 X
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o9 u# C4 L& e$ T8 X$ c set intersection? false4 e9 d$ H! D# p8 t& u; W! e
set auto? false
0 Z: Y) j9 E7 H E5 O. E set green-light-up? true& F: v2 ?' Q7 A8 z3 A E
set my-row -1; Q$ u# T" o( _+ W
set my-column -1( p2 d% C/ h0 D8 ?7 \ f# B9 z4 l" S
set my-phase -1
5 V. R8 j# b% g3 l+ q set pcolor brown + 3, x. w7 x! v# J
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;; initialize the global variables that hold patch agentsets; k* ~4 p5 W: I5 L% J1 m3 j1 j
set roads patches with
4 y5 \2 o8 Z x* v [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: v8 Y( Q! U; @; g$ ~/ @ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]- D# y$ n) J5 L$ E1 a/ ^" ~
set intersections roads with$ i% n8 S2 ]7 u/ x
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and5 V8 I8 ~; e0 X, }0 n0 P* ^
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 [5 m& A( o! \6 C& c @+ K% d; ^
1 u* ?5 @7 o. K! B/ Z" y ask roads [ set pcolor white ]+ E: l, L8 {% E3 S9 C) Y W
setup-intersections
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+ K$ `/ h1 d3 D: n其中定义道路的句子,如下所示,是什么意思啊?7 p! m! L3 e/ a1 z7 K4 _
set roads patches with
. Z* C( E9 |# ^4 M. D) s0 ^) y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" p8 h5 S& k# {" n$ m0 R8 A9 h- Q* M (floor((pycor + max-pycor) mod grid-y-inc) = 0)]" o' Y& @0 v. w; d! I3 I! @: F
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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