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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。" \$ M6 ?- c: Z4 ]
netlogo自带的social science--traffic grid这一例子当中,
! G. e, z/ M7 H/ }1 P, _2 Eglobals
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2 P5 v x' h. D2 D grid-x-inc ;; the amount of patches in between two roads in the x direction
" y+ ^6 B8 t3 m+ u grid-y-inc ;; the amount of patches in between two roads in the y direction
$ l, P/ j6 {2 N+ A! l3 W, ^$ _+ Y0 Z acceleration ;; the constant that controls how much a car speeds up or slows down by if4 V2 d8 o+ o- {& ]) N. D& q! K
;; it is to accelerate or decelerate
) i' R9 @1 V* K) z phase ;; keeps track of the phase; |3 m# K! x! C8 u( D2 Q, \/ t
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
3 u! i4 D) n" c& W current-light ;; the currently selected light4 y1 f& ~' T) c6 N+ k0 V' ]8 ?* q
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;; patch agentsets
: G5 K, D# o2 k/ L intersections ;; agentset containing the patches that are intersections
. A+ v; X% l+ K$ m" y roads ;; agentset containing the patches that are roads) N* F1 Q7 l" q0 R( y2 L
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turtles-own
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speed ;; the speed of the turtle
8 |/ N2 T5 w- Y0 P" A up-car? ;; true if the turtle moves downwards and false if it moves to the right
, K7 R2 j3 Y, @/ N9 p* V4 P) ]/ i wait-time ;; the amount of time since the last time a turtle has moved: g6 E$ f0 x0 U- N
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patches-own% p5 X+ C) K+ K5 v, L5 K& r
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intersection? ;; true if the patch is at the intersection of two roads
' i$ C O* t5 R4 h green-light-up? ;; true if the green light is above the intersection. otherwise, false.+ m4 `6 [2 r, p# u/ y5 L: ^
;; false for a non-intersection patches.1 d* _! L/ Y& q: N7 _
my-row ;; the row of the intersection counting from the upper left corner of the+ ]4 y- A" p, T7 H
;; world. -1 for non-intersection patches.# N: D+ \! i6 u
my-column ;; the column of the intersection counting from the upper left corner of the
6 } y4 J! C% y! e' J ;; world. -1 for non-intersection patches. d c- y5 @& Q/ o- _: ?
my-phase ;; the phase for the intersection. -1 for non-intersection patches.6 I0 R. {; d: ]; L/ b. h3 a* n# N7 _
auto? ;; whether or not this intersection will switch automatically.
% F" h) Z* N8 B6 C* \ ;; false for non-intersection patches.' g4 _$ x6 h7 k6 V6 I, L; h
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;;;;;;;;;;;;;;;;;;;;;;
$ b @/ X- W; O' {;; Setup Procedures ;;' ^. {5 U1 S+ W' o' ?# ~
;;;;;;;;;;;;;;;;;;;;;;# e6 K, v5 O6 G" b7 Q
- @! J/ Q0 y: h+ b;; Initialize the display by giving the global and patch variables initial values.
6 E8 e- p0 i6 u# G0 H! B( L;; Create num-cars of turtles if there are enough road patches for one turtle to. K" [- U ?$ z( ~) E/ z- D
;; be created per road patch. Set up the plots.
2 S. D* ]6 [5 [% n& g) E3 {to setup( x* }4 O9 w5 I
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setup-globals
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3 w1 a$ c n5 k! V' A4 [& r6 U ;; First we ask the patches to draw themselves and set up a few variables
5 g1 w: o4 s# @; g W6 g* o" ? setup-patches
7 ^8 Q6 F6 B# A/ z4 }* a make-current one-of intersections
' Q* M+ |8 N. |( _8 E) T label-current- H+ e y1 c$ r2 e, b
8 u5 z% N' A- I' i: y3 C set-default-shape turtles "car"
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: r+ ]- k6 }& B$ q* y) c1 U5 p if (num-cars > count roads)
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6 T6 [) m0 V) B R user-message (word "There are too many cars for the amount of "+ T" ?0 J/ N" G( x
"road. Either increase the amount of roads "
- Z! Y" `, t0 ^6 Q "by increasing the GRID-SIZE-X or "
" e+ W* p' s3 ^ "GRID-SIZE-Y sliders, or decrease the "9 d2 E1 I) u- U/ L3 H- ?6 W3 H
"number of cars by lowering the NUMBER slider.\n"
* Z' Y. \; f3 \6 c7 h: ?2 M* s "The setup has stopped.")
8 ?4 O+ Y' i% a G/ w/ o stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color w g1 x, t7 h+ s3 E8 X
crt num-cars
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setup-cars! W. S& c4 d$ v( E, n
set-car-color! @' M; }/ V; N$ y' S6 H9 T
record-data, |9 L5 ]" B/ G+ q. D
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;; give the turtles an initial speed
6 y4 I7 F. S* y0 }9 g# x9 x+ V ask turtles [ set-car-speed ]
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2 |6 F7 r) }* N6 ` B reset-ticks
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+ F3 o6 B6 k. ~! a+ `, s;; Initialize the global variables to appropriate values
' s7 G8 {4 ?' L h4 O/ n% ~to setup-globals' O2 ~! A0 B* A/ ^
set current-light nobody ;; just for now, since there are no lights yet3 ]' @& W4 s0 w# h' i, O
set phase 02 [; F1 w$ v$ z( ~# w8 K
set num-cars-stopped 0" _/ B- ]3 S1 P. u
set grid-x-inc world-width / grid-size-x
( z# X7 y, H' f 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
4 x" \% q% e2 _1 Z1 J* H- h! g set acceleration 0.099
$ s9 O# S8 |3 K) l6 @end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,& F5 f% y0 z: W, y% Z! C
;; and initialize the traffic lights to one setting; N' Y- ~" ?/ O, f% I$ M( x
to setup-patches
$ H" P0 n' q; s' Y: F) K! W6 z ;; initialize the patch-owned variables and color the patches to a base-color! P, ?1 D( T( _7 q+ F1 _. _
ask patches$ g/ D7 C4 W3 b/ z
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1 X' e8 }; J" R" B2 X- s- e+ r! ^8 A! t set intersection? false! X6 I* j& ~' h1 B% B2 T' ?+ c m
set auto? false+ m9 Z9 G! v n# t% _/ ?
set green-light-up? true4 u) E2 R5 |" x* ~# T- @ w
set my-row -1: D* X+ w; C* K9 {# s" I- L
set my-column -1
6 r- G+ d: _' Z( R set my-phase -1
& j' C& s r* S* K- O set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
. A1 h) }7 e3 h' f1 M set roads patches with
. d$ V, h( T/ ]- w [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! l$ @" v; t5 q( G0 J7 O (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ S* c# Q) N+ q$ N1 c set intersections roads with
$ d+ m' `0 b# x+ E1 q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and, l/ C8 J" y$ D& d5 n3 [
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]) a5 u, U# n J: k b, O! m
, ]4 y2 |* r2 p& J/ _+ ]. I ask roads [ set pcolor white ]
4 J- }- f4 I& O7 q- I O6 r setup-intersections
8 b6 F& x Q. b" U* Z0 ?end
. j' g0 t K% _7 p) f: B4 x% O其中定义道路的句子,如下所示,是什么意思啊?
; e+ G& D5 j# B1 Q8 I. w% l set roads patches with# V; T5 y" p, R) o! M- Y! L
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; Q6 W% n' Q3 p" N! ^ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 g8 C; X) a8 W5 R
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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