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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。
z7 }7 V- X! [3 g; F M( |. Lnetlogo自带的social science--traffic grid这一例子当中,) J4 s. P5 _ b% p7 V8 r
globals' n. Z G" H% n# I7 R
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grid-x-inc ;; the amount of patches in between two roads in the x direction
7 {! l$ M: t: k" r& h: J6 u3 `, Y grid-y-inc ;; the amount of patches in between two roads in the y direction$ f6 V" F% m/ [1 O5 h& u! t" `
acceleration ;; the constant that controls how much a car speeds up or slows down by if
5 N1 Y2 ?9 g* y$ e0 R9 @ ;; it is to accelerate or decelerate
, X! p4 `4 H: c" c: s& V6 f T phase ;; keeps track of the phase
) j8 U/ R6 h+ P8 G: D$ P1 q: r# b num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure2 L# ^) j# A) z0 Z% U
current-light ;; the currently selected light
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0 l; Q. [' [0 n: P2 ], K ;; patch agentsets& R7 N( d6 f+ S+ d8 s
intersections ;; agentset containing the patches that are intersections H& V2 J8 r2 j) M# h V
roads ;; agentset containing the patches that are roads( }+ ]' X: `' \
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( c: ]9 D$ s- `, F/ p' p6 Mturtles-own2 B6 E/ E( H. S5 l! a" x# o
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speed ;; the speed of the turtle
4 v. ]1 L3 l) B up-car? ;; true if the turtle moves downwards and false if it moves to the right. o# a' ]! Z+ q9 J+ _! {5 K; z$ h
wait-time ;; the amount of time since the last time a turtle has moved
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8 K% H. s* [# k# Z" P3 Rpatches-own
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intersection? ;; true if the patch is at the intersection of two roads! E( ^8 A5 U& _# `$ ?
green-light-up? ;; true if the green light is above the intersection. otherwise, false.7 i0 g# p) J5 C% }7 l
;; false for a non-intersection patches.9 W- E- i8 h: @9 L' p4 G" L7 x( {
my-row ;; the row of the intersection counting from the upper left corner of the+ ^/ @/ b: V1 a6 [: A
;; world. -1 for non-intersection patches.
- W$ `2 {0 H+ ]& b# a) J my-column ;; the column of the intersection counting from the upper left corner of the7 X( \, H$ T7 R$ R/ C
;; world. -1 for non-intersection patches.( }' Q+ `; Z3 ]! }7 E: u
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
2 A4 U! \$ R$ c/ ^$ i auto? ;; whether or not this intersection will switch automatically.; J# g8 [0 [/ \
;; false for non-intersection patches.
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$ q5 ^. r1 R$ C+ h$ s;;;;;;;;;;;;;;;;;;;;;;
, W/ N. x3 Y$ Z7 }. H1 O;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.# l4 {: m( h7 P
;; Create num-cars of turtles if there are enough road patches for one turtle to
) h% @0 D% @5 j;; be created per road patch. Set up the plots.
- Y+ {6 k7 ]) X% O3 }* ]to setup
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setup-globals0 _8 Z6 F" B5 V" I; R% ~. j% ?' B
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;; First we ask the patches to draw themselves and set up a few variables
1 V4 G" B% I6 ]# X2 w+ U$ t setup-patches7 M% s N5 ~5 F( D4 a% _
make-current one-of intersections/ G6 ~# `# A4 U2 k3 l
label-current
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* B' A: w/ N# }* T/ u( P- B8 t set-default-shape turtles "car"
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7 \2 d% c5 T& L, x if (num-cars > count roads)0 i2 ^4 [7 j( J* _8 r* L
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user-message (word "There are too many cars for the amount of "
) Q! U& N/ Y4 v& J# Z" J& H$ T "road. Either increase the amount of roads "
# Y- [$ s3 u$ f4 z7 ~ "by increasing the GRID-SIZE-X or "
8 f8 K5 P4 f0 C! M9 M' q& W8 E "GRID-SIZE-Y sliders, or decrease the ". J' u/ h8 F# i- ]+ {! a9 u
"number of cars by lowering the NUMBER slider.\n"
`. d2 c5 P7 b. [# l; c* }9 v "The setup has stopped.")) H+ ^# |) ^7 q6 h
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color$ K$ z* I: R. u8 E8 M2 q
crt num-cars
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" ? Z& v1 d0 L( U1 a! p setup-cars
U/ s7 E( Y( a set-car-color* R3 E4 o/ n0 H% J% V
record-data; f! B8 | ]& L! |1 N
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;; give the turtles an initial speed4 G9 Q8 P) u) p9 a9 U& K
ask turtles [ set-car-speed ]
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3 W/ ]% F& B+ F4 L' J reset-ticks; k4 v2 l# W3 H- Z% f
end9 L9 o) \8 T% P7 ^8 ?$ m% Q
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;; Initialize the global variables to appropriate values; K9 v, E: D# \: b4 V4 Q
to setup-globals
7 J8 T8 Q, [0 j9 ]/ X' Z5 B set current-light nobody ;; just for now, since there are no lights yet
+ Z- N. Y$ e+ P set phase 0
) l' s/ M- @2 f, H: [ set num-cars-stopped 0
: N1 x$ `( V3 J set grid-x-inc world-width / grid-size-x+ B, s( \5 Y, z, W
set grid-y-inc world-height / grid-size-y9 l- n' |, C2 K y8 m6 X$ ?( D
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
$ h4 c' X' j0 t; U' B( @% B set acceleration 0.099
/ v* M4 l" F$ b- U: K A gend' T8 H1 T2 ^" z. k
' {9 p* o! ^' a# F2 C;; Make the patches have appropriate colors, set up the roads and intersections agentsets,$ n+ K) P4 ^) q+ f$ _1 h
;; and initialize the traffic lights to one setting- y, W/ Y) H P- @& r) h4 l, J
to setup-patches5 B: B0 s! j! U
;; initialize the patch-owned variables and color the patches to a base-color w9 ~, y5 g+ e( o) p8 q
ask patches/ X: B8 G! D. F
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9 Q$ N; s! L# a) o% k set intersection? false
# s! N" n3 g8 L5 R set auto? false( R9 T' L5 P. v3 L
set green-light-up? true
. X# ?$ w2 z7 y- Y set my-row -1& F9 i% N0 d# K! G' Y3 R; D
set my-column -14 L3 _5 e2 N! n0 A3 U3 x5 J, j* S
set my-phase -1
' f* w+ I# U: u& |4 b set pcolor brown + 3
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$ X" ~7 x( |+ N! ?; ] ;; initialize the global variables that hold patch agentsets9 w# l' \+ b7 \" W
set roads patches with" f3 p9 S3 B: d* B3 R1 O2 K3 v
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or3 a7 `' [) R2 _! p8 k
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 ^3 m# q9 i: \ J7 ? set intersections roads with
& @, ~4 T) Q, |8 }$ |/ v0 A6 l6 L [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
7 B- Z3 m# H7 Z9 }8 @$ Q6 j. f (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]) M0 \8 Q4 e/ L: R! @) q' W
setup-intersections! e/ n6 A* H# X; |# V
end2 N8 [7 i+ ^8 m( \6 o
其中定义道路的句子,如下所示,是什么意思啊?
! `3 L( T/ J- F; i5 @" k set roads patches with# e3 \+ ~: o# c3 M1 @( N, Y
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% |8 S! h n9 M* V# c& Z0 p# o
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# }9 i2 A( p/ a6 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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