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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。
+ ^4 T X: ]& ^4 v- ]& Inetlogo自带的social science--traffic grid这一例子当中,6 X0 U1 ]. E1 b6 h2 l, [5 j2 W
globals& [( H& Y: O/ m1 P: F+ _2 S" ?) P
[
, j' i% y& e0 E I+ `5 d/ E) @ grid-x-inc ;; the amount of patches in between two roads in the x direction
) r3 @# O& S( _7 q0 b grid-y-inc ;; the amount of patches in between two roads in the y direction
Z/ `1 Z! j- ^, F acceleration ;; the constant that controls how much a car speeds up or slows down by if
7 V3 W* j5 Q. _4 _ ;; it is to accelerate or decelerate
2 |, u2 s4 U. ^2 N phase ;; keeps track of the phase; L1 X7 Z% B) w; _" a4 q& s
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure. p% p7 b: o: }- i+ V
current-light ;; the currently selected light9 s+ a, C+ X( B+ G
: M% K& t4 W$ a3 X" C ;; patch agentsets9 j! U% A: V6 V5 u
intersections ;; agentset containing the patches that are intersections
- y0 B. T3 m x# ]- ^ roads ;; agentset containing the patches that are roads+ [: t4 j o9 p" d6 {
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+ `8 w$ M% j ^turtles-own
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speed ;; the speed of the turtle
3 w* x I, Z) c/ k up-car? ;; true if the turtle moves downwards and false if it moves to the right
) w3 C( J+ @1 a/ q( \( t wait-time ;; the amount of time since the last time a turtle has moved$ G) O2 C7 |) N
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patches-own$ M2 k2 b, g7 F- h' E! ^2 l
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intersection? ;; true if the patch is at the intersection of two roads
$ E& N$ F5 U0 a. [, J- a1 b! n' c green-light-up? ;; true if the green light is above the intersection. otherwise, false.! p! h1 o: X/ {; j2 H; {* @0 l) [6 q
;; false for a non-intersection patches.
9 j5 l% r [8 l, W5 @0 @ my-row ;; the row of the intersection counting from the upper left corner of the
, \/ M7 y6 c& C, b: h ;; world. -1 for non-intersection patches.
g- N+ L6 R. H0 `5 E+ [$ S& ^ my-column ;; the column of the intersection counting from the upper left corner of the1 m2 v0 w- `2 v% F0 J2 ?' I
;; world. -1 for non-intersection patches.
- f5 S6 ?; G$ E) Z0 u# k8 L$ ` my-phase ;; the phase for the intersection. -1 for non-intersection patches.
7 M- y) Y& ~* I* Q auto? ;; whether or not this intersection will switch automatically.
9 c. H7 C% K% O! p; a3 n ;; false for non-intersection patches.) P2 k) f- {& ?3 g
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6 }5 g, q7 B2 ?;;;;;;;;;;;;;;;;;;;;;;
1 A# J% D) j U6 {;; Setup Procedures ;; k. l! }) E1 \# s% O: p( M
;;;;;;;;;;;;;;;;;;;;;;: A4 Q( T0 Z' I9 u( e1 s, Y! `/ l
# U, `- A6 b* h+ Z, F;; Initialize the display by giving the global and patch variables initial values.. p M. x% V, P- B
;; Create num-cars of turtles if there are enough road patches for one turtle to9 w& e# c1 Y; a- S. S% P
;; be created per road patch. Set up the plots.
. t! X% m+ p/ _5 v: Fto setup& V2 g" Y j5 R
ca$ s. ? h0 X- W
setup-globals
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;; First we ask the patches to draw themselves and set up a few variables6 g5 v/ h3 D' p9 m
setup-patches) s# C. h# u3 p
make-current one-of intersections
3 N! f6 Y% B# X, N9 j5 C label-current- }& ]$ u+ u8 l9 z
5 \; c9 ~2 X' Z set-default-shape turtles "car"
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& T! c( u. H ~$ [, f" b if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "1 A, O' e* v; G: n9 S
"road. Either increase the amount of roads "# `8 N& j3 `5 x$ k
"by increasing the GRID-SIZE-X or ") @2 g, U1 A) v1 x+ ?# }( B
"GRID-SIZE-Y sliders, or decrease the "! A/ c& u N% b
"number of cars by lowering the NUMBER slider.\n"1 I! e1 b# H# b
"The setup has stopped.")# C8 V" y h) Z1 P
stop3 t4 |; Y* H8 i- g
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$ ?6 x, Z/ X1 \7 @8 `! V ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color7 U- C' n U, g
crt num-cars
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setup-cars, B$ o) w3 T) W# Y( w( I1 L
set-car-color- j o% `, J- ^% Q* a1 c, I& B
record-data3 O I% s8 {+ ~
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$ S a/ B5 a3 L& _6 D! Q3 u7 K+ g ;; give the turtles an initial speed
# v6 H4 w" s% _' c8 W ask turtles [ set-car-speed ]. x) Q( |% Y J6 E6 z
: s ~% @1 J# ?1 h reset-ticks: V3 ]- p* O+ S! x) n1 V
end
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;; Initialize the global variables to appropriate values0 u3 S" P6 c5 Q% n. B
to setup-globals
9 s9 x# W& G0 f/ i6 F set current-light nobody ;; just for now, since there are no lights yet
5 v( \6 u {; A' Z1 u) Y set phase 0- J! }; W7 U8 G
set num-cars-stopped 0
6 o& t! K% P2 I1 {( _ set grid-x-inc world-width / grid-size-x
; |5 s. d, L+ C5 T4 R4 k set grid-y-inc world-height / grid-size-y
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( N2 i, g9 ^8 L5 t# v L ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary6 S/ Q; H# H& D) X# v% e
set acceleration 0.099
( V8 x' `; `6 _7 Z$ X0 F1 i1 D6 lend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,* H7 f! P; c0 ~& {. ~
;; and initialize the traffic lights to one setting
+ N6 i1 M' v. \3 rto setup-patches1 i! L3 ` N5 M7 @# Y% t0 f4 K
;; initialize the patch-owned variables and color the patches to a base-color
0 C/ O- j* Z# g ask patches
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set intersection? false
4 x9 L) S7 R' Y) @ set auto? false
$ E5 }* ~$ O. R5 e set green-light-up? true
7 K; N) K9 x# Z5 P: Z0 u7 T. }/ z+ B6 w set my-row -1
& y# c$ S, x; {8 T set my-column -1; J3 X7 k1 h* c2 m6 T
set my-phase -1( r o0 l5 U5 y( \- m1 R7 |7 Y
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
' j& l3 K+ L: x set roads patches with
( ]' ]5 F% _7 z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) v4 }2 p) t! y' U( [+ L
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 ?0 n( k* ^, y6 d set intersections roads with
5 C; D) x) B1 _ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
' \( Q) v. Q3 g7 d4 u* o& C; l: _ (floor((pycor + max-pycor) mod grid-y-inc) = 0)] r1 k% \) y, _0 A
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ask roads [ set pcolor white ]( f, x$ q0 \5 O$ [ i4 O. q
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?
0 M! E7 p* A5 t2 x6 m2 p set roads patches with3 d( C9 C& W+ g# N0 s
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 H+ ~) o% Y/ B2 M* c (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" d1 G+ A% ~5 {* B. A, D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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