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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。
) t7 l4 O" W) U% Vnetlogo自带的social science--traffic grid这一例子当中,
: z8 t# j* T1 f. N+ Aglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction; J3 P) B s8 m/ B/ M
grid-y-inc ;; the amount of patches in between two roads in the y direction
7 \0 M; ^* j1 \( ] acceleration ;; the constant that controls how much a car speeds up or slows down by if! K- a' D! C/ V' }
;; it is to accelerate or decelerate
$ U+ L: m& J: ^ f7 d B phase ;; keeps track of the phase
8 V* m' R2 G$ u, V4 y+ w" ^( T num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
t0 [$ o* r" u- j$ a6 t3 b2 Y current-light ;; the currently selected light
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;; patch agentsets
8 Z$ @1 t) S/ u+ W& T' p. d intersections ;; agentset containing the patches that are intersections
3 L$ z' y5 c1 ?# H7 O _ roads ;; agentset containing the patches that are roads0 y! k6 q, p" J. u
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( g: r, Z- c! I4 ]2 l9 g+ e9 Bturtles-own
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speed ;; the speed of the turtle7 t$ w* ^& E. S4 G. ?" c
up-car? ;; true if the turtle moves downwards and false if it moves to the right
& n. n/ l. Y: f9 g2 H. o3 j! Q wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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2 ]4 P/ |1 B/ t$ C2 q: _ intersection? ;; true if the patch is at the intersection of two roads
, I+ J$ n9 A# q# m( c2 x7 `; m' C green-light-up? ;; true if the green light is above the intersection. otherwise, false.
) l% s6 q: q- v ;; false for a non-intersection patches.2 K2 @2 n7 ~0 K \ n/ l/ Y
my-row ;; the row of the intersection counting from the upper left corner of the
5 L7 l1 Q# M5 J/ a. ]% X ;; world. -1 for non-intersection patches.4 C# A+ y. p8 f2 f
my-column ;; the column of the intersection counting from the upper left corner of the) T" h: }" f3 s2 E9 `+ a
;; world. -1 for non-intersection patches.
9 ?8 @' U$ ?# h2 O my-phase ;; the phase for the intersection. -1 for non-intersection patches.
/ r% o8 I7 K# F9 | auto? ;; whether or not this intersection will switch automatically.
3 A4 L& V( }$ ~ ;; false for non-intersection patches.; B% ^/ d5 R+ n' t% F' B$ r
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;;;;;;;;;;;;;;;;;;;;;;- d2 a k, K0 W2 ?% L$ W7 t
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.6 C% x4 e) D! C% V- l
;; Create num-cars of turtles if there are enough road patches for one turtle to
], q7 F+ i0 _$ y3 o2 f/ ~1 U1 ~;; be created per road patch. Set up the plots., d9 b( q& C3 c0 T; ]
to setup& k2 S4 d: K1 E% w
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
+ s7 |5 p3 J' o; Q1 R. e setup-patches9 Q u$ q: a; _: K9 C
make-current one-of intersections
7 P! j& E: S3 j8 C label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)! T2 F! J( X9 [2 M% r
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user-message (word "There are too many cars for the amount of "4 r$ c! X( ^6 t& `
"road. Either increase the amount of roads "
: |- G2 L+ N, ] "by increasing the GRID-SIZE-X or "" W/ |! T3 n( X, X& T$ L
"GRID-SIZE-Y sliders, or decrease the "
( {- I: ^: d0 ?& g: I4 q "number of cars by lowering the NUMBER slider.\n"& u+ {- R4 S. ]9 j
"The setup has stopped.")
% |6 v0 O+ G$ Z, C/ J# A% v2 B stop) H& A! v2 G& \8 O! @! m. Z
]
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; ]! ?" L4 ~8 e/ D0 U% I ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color3 `) ^: s8 }: E* ~! R+ @
crt num-cars
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J) p" ^. M) b/ ] setup-cars
9 W4 H6 T) c$ W5 \2 c set-car-color: ^) W8 j" s9 r2 i" V- d) S# @" c
record-data% P) q, A& d1 e7 ^$ o. U
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q2 u9 Z1 ~ ~& y. S ;; give the turtles an initial speed: O8 K0 w9 {1 Y5 T h2 H+ ?
ask turtles [ set-car-speed ]
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% j3 V# g: t) x9 P- J8 E6 p reset-ticks* v {" j' u4 i! F
end
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+ N+ J" I0 }7 `5 E;; Initialize the global variables to appropriate values
$ w$ j3 c! A6 [4 m. ]/ yto setup-globals
! b9 ]; g% A# V6 e set current-light nobody ;; just for now, since there are no lights yet
+ K5 e& U5 `/ M: W' ], s3 W! ~ set phase 0
' ~) x9 \6 c7 G2 v' e( p8 r7 X( B set num-cars-stopped 0$ V) B7 H5 T6 l# \0 u$ H
set grid-x-inc world-width / grid-size-x
9 |6 I( k+ j, s% l1 X$ h0 y0 U# g7 b' E set grid-y-inc world-height / grid-size-y. t4 H/ U5 |# Y8 J. F, t
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
1 _( d! i- h: T6 y5 ] u$ E1 H set acceleration 0.099
+ `" K6 ^0 ~7 P' Pend' a: F3 Q* F: Q' c. S0 C
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
9 ~% R0 {& I" D: n9 F; J3 A/ u;; and initialize the traffic lights to one setting0 Y" o# w2 G- |- ^
to setup-patches
) ?" C$ e" Z8 Z* J ;; initialize the patch-owned variables and color the patches to a base-color
1 \! S# u A- i8 ?- u ask patches1 o2 Z, s1 H+ e' v# a' _1 F
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set intersection? false. |# A% ? a" ]
set auto? false' p) a* Y. T5 s2 q [, k. ?
set green-light-up? true/ C. n0 c% A4 U! B: k0 q9 u
set my-row -18 \ c$ N2 Y h% Q: ?3 P) ^
set my-column -1
5 O% S: |9 {! i* i- B set my-phase -1
! V( A4 A8 Z7 E" ]- o set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets$ d% M- Q' {2 F& B
set roads patches with8 O7 z! u7 g5 E
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or* [, i" l A1 f5 v# X' B4 M3 S
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]# h9 Y% X0 ~( p! _$ b. b3 ^- \
set intersections roads with
' ~+ [" X0 K/ O4 [! ? [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and: U2 Y0 ?- }' [- L) Q1 f
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
: i2 e% I/ _6 B; @* ?# d* |4 c setup-intersections
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& ^( n; `6 R$ T其中定义道路的句子,如下所示,是什么意思啊?# f) {/ l, m# j2 N1 u( s
set roads patches with
$ h/ d. H ]+ X% }! H$ D [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or3 M$ }+ X" x! Z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* n+ S$ Q' k7 H) c* R8 w 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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