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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。/ w' M/ P/ y" |; m5 p. y: T0 s8 h
netlogo自带的social science--traffic grid这一例子当中,5 J, C2 v1 U0 s. n) ^' J# H5 \
globals2 ^% N9 i6 t; _& Z. ]$ v
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grid-x-inc ;; the amount of patches in between two roads in the x direction
" F% y( e$ q8 u grid-y-inc ;; the amount of patches in between two roads in the y direction
; M @2 o9 z2 j! |) t* y$ Y acceleration ;; the constant that controls how much a car speeds up or slows down by if! f+ ]; \2 @& S- v e
;; it is to accelerate or decelerate
1 l: S' y$ P# E# a4 @( }: s phase ;; keeps track of the phase1 h* N7 F+ J: u: ~/ }3 G
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
/ J0 |/ X& y% s/ \6 ~8 f current-light ;; the currently selected light2 L4 O" p9 h- k3 v1 e8 D
/ x6 l; O5 u' }2 A3 \ ;; patch agentsets
( e! E( B( B( c4 x @ e4 G intersections ;; agentset containing the patches that are intersections) M" _2 H8 R' ?9 u9 I) }9 w
roads ;; agentset containing the patches that are roads' h! S" J& A @4 q5 k! q
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turtles-own D. A2 ^8 ?& U, ~ c
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speed ;; the speed of the turtle
* V" E! \( p/ k, Z+ ] up-car? ;; true if the turtle moves downwards and false if it moves to the right. [: x# B4 _" O4 e* u& u! [
wait-time ;; the amount of time since the last time a turtle has moved
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) {" r% p3 P0 T+ B3 p* |& N3 D: ]patches-own- F% ?' u0 u3 s0 l# O
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intersection? ;; true if the patch is at the intersection of two roads3 l. h" T2 G0 z! L# N( f2 }
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
2 t! H5 ~" r8 O. U- M, A+ R ;; false for a non-intersection patches.
' W& q0 s% B8 D* ~4 ]) N- V- Y' _ my-row ;; the row of the intersection counting from the upper left corner of the
8 }8 P) o5 F7 `- E v ;; world. -1 for non-intersection patches.3 W5 n& ~2 J6 L. D+ }
my-column ;; the column of the intersection counting from the upper left corner of the
* ? [7 m$ F$ g, j$ b7 I ;; world. -1 for non-intersection patches.: _. _/ v: |0 j8 o( C6 p! {
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
6 l7 m m' Q8 F& ~- d! `4 j6 o4 X auto? ;; whether or not this intersection will switch automatically./ K: q% }& W8 l3 p" n+ z9 H7 X
;; false for non-intersection patches., ^; c2 }- i* |" n
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;;;;;;;;;;;;;;;;;;;;;;2 @* T- W3 O, @! ]! X/ [7 t3 ]8 U/ ?
;; Setup Procedures ;;
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) [& t& t; O- i, n0 p' z7 w9 i: Q3 X7 i* ^;; Initialize the display by giving the global and patch variables initial values.; H2 i$ R) ^ c+ t9 q1 M( A
;; Create num-cars of turtles if there are enough road patches for one turtle to. v, Z& T }# J
;; be created per road patch. Set up the plots.& d# `( V# Z! G. ~; V8 o! E
to setup' f% E3 m ?- v {
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setup-globals9 x# f1 O5 `2 ^4 x5 k1 _
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;; First we ask the patches to draw themselves and set up a few variables, \0 S1 m6 t7 H9 f* e& ]$ l3 t" K
setup-patches
+ D0 E1 u( m- @% k' o5 ~ make-current one-of intersections7 s9 z1 p, u J {9 K% B! T
label-current# L/ r9 n" t$ y8 f
1 ^- o. U5 E$ Z6 v9 q6 e7 Z set-default-shape turtles "car"* i+ a) p3 S" i) R. f+ J
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if (num-cars > count roads)+ m5 V: E! O( o8 N6 A
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user-message (word "There are too many cars for the amount of "
7 S/ I- B; ?: ~/ n "road. Either increase the amount of roads "
) S( V* `1 p- q0 ]7 n, o "by increasing the GRID-SIZE-X or "2 S: {6 \; T' j" w1 t/ v5 C
"GRID-SIZE-Y sliders, or decrease the "
9 v- F3 F- t4 e "number of cars by lowering the NUMBER slider.\n": \$ {3 G; [4 N
"The setup has stopped."): g9 C. ~9 e8 r3 d
stop$ g7 \+ ?. ]6 @* o4 y4 \
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
- A7 a1 p" r1 L% ?- e& g% g% Y crt num-cars
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" s0 z& g2 L% z8 [: v* y setup-cars; z7 @" s. M1 w' J1 F% q- ^/ y! V
set-car-color
+ i, P2 B0 x/ W* m9 W5 X record-data2 C9 _1 A8 i2 S6 O: s; v
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;; give the turtles an initial speed
4 G9 W+ A% U# g& }7 q ask turtles [ set-car-speed ]
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. l) Q) j; w$ ? D reset-ticks7 N+ S1 q9 ^4 }" l3 [
end" F" L) \3 ^9 C& j
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;; Initialize the global variables to appropriate values8 {$ l) g9 w+ `2 p
to setup-globals
1 o, ^1 U6 n5 v: \. z& v set current-light nobody ;; just for now, since there are no lights yet2 e# Z: j* P1 \8 R# b
set phase 06 R! S% @2 t) k$ D5 g$ A- ^( h
set num-cars-stopped 0
% F8 j" I2 N9 ` t" {' |1 r set grid-x-inc world-width / grid-size-x( i& `% j$ ~& h% H4 E% P
set grid-y-inc world-height / grid-size-y' t0 }" F" e0 T5 G8 U+ h- |
+ G3 t/ P, `! c ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
# \# G: e) e8 X* f6 p Y7 y set acceleration 0.099$ B# v6 ~9 a( f/ w4 W; R
end" ?! `( P0 i3 r! g" L
" r/ \. R$ _" _+ L- Z;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
; i y5 P1 ^0 U. B- R;; and initialize the traffic lights to one setting
% }4 b1 h) D+ }& z5 o( \0 ]7 V# E6 Pto setup-patches
" j. ]0 e; Q+ M3 g) P ;; initialize the patch-owned variables and color the patches to a base-color
& g# B: R# O% X3 d0 a ask patches
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1 W) b+ U1 s5 [" ~$ v' t- T9 V set intersection? false/ q8 N c8 U& Q) H% \
set auto? false0 z" S) ?3 Z$ S. w& p1 C, ~: H/ _
set green-light-up? true
2 R ]0 S0 h+ N1 H3 _1 K set my-row -1
' O4 |- {+ c2 p set my-column -17 |0 v( w! y" D
set my-phase -10 \1 \5 Q" H2 A9 `8 K% j7 K4 g
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets t* P& ~9 b! A& j
set roads patches with3 R4 S* ~9 F/ ~
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or7 L7 ?4 P$ }+ w; w; G4 Q
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 Q" H1 d7 |& [0 L2 y( {2 [
set intersections roads with0 a$ n9 \+ ^+ h/ ^" m/ U* T9 t
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and3 [2 M: q+ u4 M/ y# f) q1 r
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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end
/ z& Z4 S9 [2 x& w! z) b其中定义道路的句子,如下所示,是什么意思啊?
8 G6 ?; A* J" B2 V$ U% e5 i5 i r- ` set roads patches with
. B: M" i! o; r3 q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
) q7 t' R, L D+ o; e (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' i |. p; y% i. r5 {" A6 k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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