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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。+ i2 V4 Y' ^/ Y* x9 j1 ^
netlogo自带的social science--traffic grid这一例子当中,& K, u2 v; `& Q8 O! Z
globals8 Y, X7 V' g9 Q( H# G6 [
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9 d0 e; K2 d, }; t6 D% f( F grid-x-inc ;; the amount of patches in between two roads in the x direction
$ _7 e! N2 [% b grid-y-inc ;; the amount of patches in between two roads in the y direction
8 w! b. E$ [. P$ J; ]6 l: P acceleration ;; the constant that controls how much a car speeds up or slows down by if9 ^& h) }7 a" z4 X1 ~
;; it is to accelerate or decelerate7 E# d2 H' [3 x. ^! x1 V# J. L1 M
phase ;; keeps track of the phase: V5 c" H$ V7 e6 g1 D) f
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
8 S/ O6 O5 P6 w current-light ;; the currently selected light
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;; patch agentsets
: i- H# k) d- `+ A4 w, h) u intersections ;; agentset containing the patches that are intersections
: G9 e% ?1 F4 `" g5 h# X. R/ O* V9 j roads ;; agentset containing the patches that are roads
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4 b0 g7 |. Q5 ?9 P) z* Aturtles-own
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\- C( N4 Z6 z) S' v0 [ speed ;; the speed of the turtle5 t. B2 _ X+ V2 v. U
up-car? ;; true if the turtle moves downwards and false if it moves to the right3 w- ^6 _5 g" j t( U1 `
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own+ A4 r$ H* o) A3 I/ C
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2 J. F1 @" @4 N+ d/ P4 ]& D intersection? ;; true if the patch is at the intersection of two roads
2 k* @9 m; L" E1 @" p green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! } g5 Q+ T$ _& Z, l+ J- E6 F3 R4 R7 y ;; false for a non-intersection patches.+ H1 b, V# B3 ` v& i( h
my-row ;; the row of the intersection counting from the upper left corner of the
6 `( S( y& q* Q2 c ;; world. -1 for non-intersection patches.
2 C" m+ t+ W. c- p my-column ;; the column of the intersection counting from the upper left corner of the
9 N. [; A9 z; F* X; F ;; world. -1 for non-intersection patches.
& x- _6 i, V! f. {( U, p+ V my-phase ;; the phase for the intersection. -1 for non-intersection patches.+ ]% F* H# |3 x. f" X3 R
auto? ;; whether or not this intersection will switch automatically.
' F% h& ^! y J5 ]2 h2 f! g/ } ;; false for non-intersection patches.. A# u) ^+ O; h" N, J
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" x- {2 ^& h1 z7 Q3 B1 R;;;;;;;;;;;;;;;;;;;;;;
6 C( z+ H6 }% D( X;; Setup Procedures ;;' J2 s( ]$ z) _
;;;;;;;;;;;;;;;;;;;;;;) B2 k/ o' b/ ?! D! A; C
1 i* f1 o6 X9 Z% q/ m# L( J;; Initialize the display by giving the global and patch variables initial values.- G; V) m9 c( |- ?" K( [+ Q
;; Create num-cars of turtles if there are enough road patches for one turtle to5 {6 ? C6 ~% l( ~. q/ v
;; be created per road patch. Set up the plots.! C. x: \& v( V; n% J- d4 p
to setup( i3 r5 O. v r$ M3 `
ca
3 N0 U; I b- x. B& m setup-globals6 p8 B* J. q' c! y, ^ z
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;; First we ask the patches to draw themselves and set up a few variables
% s5 J C% j4 T9 z setup-patches; O0 B9 t2 ?2 p, b4 j/ D
make-current one-of intersections" n0 D+ f# z* O! {2 | E) G
label-current
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set-default-shape turtles "car"
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9 J9 d: M2 r, D4 h+ l if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
+ d# S( ~6 G' z2 w "road. Either increase the amount of roads " K! r1 }* x1 @* }. x
"by increasing the GRID-SIZE-X or "5 U/ S5 o) p4 S; E4 T* E6 Z
"GRID-SIZE-Y sliders, or decrease the "% n$ B6 `/ q0 L/ E% T8 W
"number of cars by lowering the NUMBER slider.\n"
( a, H0 }5 v2 I- Z "The setup has stopped.")
+ A6 f3 G+ v' G' R7 \* f stop- G3 S" P4 q6 T6 y. F' j: A3 W
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/ n7 B- j6 J6 f/ k6 u ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color5 t* c5 X. t1 T1 ^
crt num-cars! p R/ }1 y& M6 V& t/ ]
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5 ^2 A) f& u1 \+ D ? setup-cars
: z9 u$ B; E6 q: m set-car-color% o. d& P# V0 ~
record-data( J9 d0 j0 d0 L9 F1 x; }3 s. l; a
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;; give the turtles an initial speed; g* N+ O, j% u) V; `8 u4 u
ask turtles [ set-car-speed ]
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2 o1 f: S* t/ `1 k/ Y. Y) u( n8 _) B reset-ticks
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;; Initialize the global variables to appropriate values0 M8 K6 s# b; T: t! y
to setup-globals
+ D6 r5 U; v! E6 ] set current-light nobody ;; just for now, since there are no lights yet
, H. z* H. x6 G. u& `1 S$ G set phase 0
. m' q7 Z ]" s. V0 l* q W' \ set num-cars-stopped 0
W3 \5 H& a# t set grid-x-inc world-width / grid-size-x2 w0 V& U3 e8 R% G
set grid-y-inc world-height / grid-size-y8 {0 _" j; A& s
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary! O6 B" W. ^" w; m) H
set acceleration 0.0992 x% B- o1 ?; _6 c4 D/ Y/ c) J' Q# e4 D/ ^
end m5 a" F1 `+ _5 }$ a* o
8 \2 x! y, {9 D5 ?) N- S' e5 Y;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
: ~2 t+ h+ `# f% o1 V2 R;; and initialize the traffic lights to one setting& q' I: \; H2 _* L
to setup-patches; B% L7 i/ J+ T& F
;; initialize the patch-owned variables and color the patches to a base-color- b) S% {+ r: U0 A+ j& ^
ask patches
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# f6 U y* X0 b9 ]2 b& B ?9 A set intersection? false
; m1 o8 O0 x% P: H set auto? false
* D8 n8 f1 \3 F+ M' m7 \) i set green-light-up? true% E! \1 N) R0 I: E P
set my-row -1
& b7 v) p# d: c set my-column -1' o# ~7 u. ^- f
set my-phase -1! b1 O h/ ~3 z9 d! W9 a/ K
set pcolor brown + 3
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! m# g2 w* E" @1 q( E2 L ;; initialize the global variables that hold patch agentsets
9 X" n! Q- ~' N' H set roads patches with
- Y# w, q6 a7 k, N2 |. _ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
% E5 k$ S$ I4 _9 Q. K7 [ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]( _4 W }* I' G7 Y+ [
set intersections roads with* U' i8 _. O; I* U2 j9 r
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
6 I: T) g' ?9 I (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 W# `- {- a$ j) r/ Y2 Z
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ask roads [ set pcolor white ], X# k' W5 y8 n6 w8 R/ _
setup-intersections2 M" O) a; x5 [9 d0 V4 I. v" i
end1 J/ ], `5 M" r0 j2 S9 k
其中定义道路的句子,如下所示,是什么意思啊?" c5 t& [0 D1 l! h2 N1 m& w @
set roads patches with: D6 b% c W( t! s. M% }
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or# s+ C: b1 l' U4 y( b" n" k5 f
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" o0 M/ w; s0 g; G" D6 S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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