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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。( m3 i* R+ W6 R* E7 ~6 u" Q* u
netlogo自带的social science--traffic grid这一例子当中,2 d0 |6 h: [: V$ `! _* o
globals
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; ?3 \3 t% s8 ? grid-x-inc ;; the amount of patches in between two roads in the x direction
3 K# A2 c0 n1 P4 ]. \8 |9 u6 R grid-y-inc ;; the amount of patches in between two roads in the y direction4 X1 {+ @) y. O- D j3 ]! S8 m
acceleration ;; the constant that controls how much a car speeds up or slows down by if/ B& {0 Z9 P. R2 t3 H
;; it is to accelerate or decelerate9 G/ U4 D2 T; X; b8 O9 l
phase ;; keeps track of the phase
7 D7 M) G' ?- i9 A num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
; |5 p' I7 M! y# q. o+ F) r current-light ;; the currently selected light
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% P! r Y6 _% M6 o" |3 G, X2 U ;; patch agentsets
+ s+ R+ R* B% J% B M intersections ;; agentset containing the patches that are intersections9 C1 g( N: _, x' o" C x
roads ;; agentset containing the patches that are roads" O& s9 \% u4 x3 D
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+ ]* J& ]$ {$ c( Iturtles-own
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2 P7 z% y& f3 t7 z% }6 \2 ?) P speed ;; the speed of the turtle
! p# s5 R: k: @ d up-car? ;; true if the turtle moves downwards and false if it moves to the right9 S4 F% |2 k5 G7 ]8 ^
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 roads5 `1 N2 _7 {5 W: T; }( r; h* q1 k& ]
green-light-up? ;; true if the green light is above the intersection. otherwise, false.4 U9 F- Q) a! z' o* ^
;; false for a non-intersection patches.
8 b8 O9 A) R! s4 d# W/ V$ {* Z5 C9 i1 y( O my-row ;; the row of the intersection counting from the upper left corner of the$ A; s* f) m! o! a2 q' i
;; world. -1 for non-intersection patches.8 r& R1 E/ ^5 o7 B6 _0 v
my-column ;; the column of the intersection counting from the upper left corner of the
+ \, X+ \' Q ^% k% i$ q) Q8 I& Z! H# ^ ;; world. -1 for non-intersection patches./ z7 O' x! E% p! u" c1 I$ Y
my-phase ;; the phase for the intersection. -1 for non-intersection patches.( m: T# h2 Y7 _
auto? ;; whether or not this intersection will switch automatically.2 ]6 Z d6 W" _3 v1 V( \" J: q
;; false for non-intersection patches.0 j$ T* l+ y5 R$ K
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1 E3 E6 n' k2 M/ R% B;;;;;;;;;;;;;;;;;;;;;;$ K1 p. C$ w5 m6 E# n' }7 `
;; Setup Procedures ;;
7 [, c0 _- w- u2 {4 m. X% c5 j;;;;;;;;;;;;;;;;;;;;;;& F2 f& [1 ?2 z) g4 v
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;; Initialize the display by giving the global and patch variables initial values.
% f8 n1 l) m* g9 q6 y$ ~ ?; B3 B;; Create num-cars of turtles if there are enough road patches for one turtle to
& |( E7 y* }9 C$ ^0 F$ F;; be created per road patch. Set up the plots.6 O7 T4 Y+ w& C6 H6 i e' a/ J
to setup F9 ^8 ?$ z5 {' ?; h* A7 Q- S
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setup-globals4 F9 K0 D5 n! q( Y
% \( Q% t6 S+ @; M0 E8 e i ;; First we ask the patches to draw themselves and set up a few variables
$ X( G0 D4 J* Y4 y1 g setup-patches# \0 W' k0 G' p
make-current one-of intersections
; I9 R: R) m5 {! O5 I4 A! z label-current: U: `; o* o: a' C, m
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set-default-shape turtles "car"
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8 A' O6 Y- H, X4 m if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
6 s! t4 n/ ~" g& o) w "road. Either increase the amount of roads "
5 \* o/ O; e1 ^( s; V% f "by increasing the GRID-SIZE-X or "
7 |- z5 L9 [- @ "GRID-SIZE-Y sliders, or decrease the "/ v% h9 o6 h2 g' t
"number of cars by lowering the NUMBER slider.\n"2 c+ c% R5 |; c" S& w3 h b
"The setup has stopped.") H6 _, w# t4 l8 N
stop6 f8 |+ x: U/ K
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$ B ~' p! B. w ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color9 t6 o- X/ o7 b5 g% O2 s7 L
crt num-cars
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1 u O" M% Q2 R( O setup-cars
; Y, W0 r& D8 Z. T" g4 T! a set-car-color
3 S' |2 T' K9 m: [, x2 r7 a record-data( w) i& @, S+ D# c9 t; z4 l, q
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;; give the turtles an initial speed9 s. A6 C4 Y3 b$ `2 t3 |
ask turtles [ set-car-speed ]( t3 }6 i- U' C% I/ v, D" Q
& b! R1 g' e7 q0 }3 ?3 c ^ reset-ticks
3 V+ J: z, g2 c5 iend
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- Q$ O5 E; O4 ^# U! h2 m# J& J;; Initialize the global variables to appropriate values4 P! U G, u1 |4 `4 X
to setup-globals
7 g( _( [% U# b) V set current-light nobody ;; just for now, since there are no lights yet4 Y$ ]# W, W& T7 t
set phase 0
2 E N6 U l/ s4 G set num-cars-stopped 0: N6 E4 F$ C8 I! p1 D% T D, B9 U
set grid-x-inc world-width / grid-size-x
' ^* L. @# u3 }; h+ d @+ d 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
7 x: m6 b, j+ [; ~" S! Z$ d+ @ set acceleration 0.099
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5 y6 p, `8 F5 }& [;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
% Z i$ a9 B" Z. n# o& H5 x;; and initialize the traffic lights to one setting
. y9 U! J; m4 g9 n; K0 ?" dto setup-patches
& M/ F6 v4 w& n6 c9 ~! A ;; initialize the patch-owned variables and color the patches to a base-color
* m [4 R1 E! R8 D( a ask patches( @$ L1 j* e: y2 L
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set intersection? false
& ]- P' s! K& U/ } set auto? false
; W- E, G$ d! @5 l5 @5 R! d set green-light-up? true
" d/ E8 K# o O0 f( L" i set my-row -1
. R5 @' a; c' P% F" d5 R1 S" z- [ set my-column -1" _ y' q; G6 x) H H
set my-phase -1
0 Y6 o V7 [% I- ~% }+ k, q/ R set pcolor brown + 3
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3 h0 v3 L+ T2 W+ U) W' l, V ;; initialize the global variables that hold patch agentsets
6 J1 q4 d: t: o% q( ~3 G4 X: O set roads patches with. Z- M+ ~# f& t, H1 Y6 y
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* f' J9 ]/ I% I% ?0 c& ` (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 L! T/ i8 o: l; ~ v9 H set intersections roads with
4 k4 s( B; S0 f+ @ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
3 Q5 e+ Z/ y& |( ^6 M5 a' |: U2 [ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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+ U- N: U' u% }1 f其中定义道路的句子,如下所示,是什么意思啊?% r4 [/ ^9 x5 ?$ q; l& I# F
set roads patches with
+ e6 T9 Q. m+ ]0 L [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or3 Y& N: Y$ O/ Z8 U
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: q6 R0 v% ^5 g: p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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