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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。
$ @! [/ f3 ?) [% l3 Jnetlogo自带的social science--traffic grid这一例子当中,( ]% C( ^- k( }
globals3 M) h, k5 l% \. |# z X
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8 ^3 d7 p& Y7 V" N& y6 X grid-x-inc ;; the amount of patches in between two roads in the x direction8 L0 V# F# h$ Y2 s6 b: T1 z
grid-y-inc ;; the amount of patches in between two roads in the y direction
" E y3 a T6 {/ x9 Y acceleration ;; the constant that controls how much a car speeds up or slows down by if
; R6 ^" K6 z# c5 d) y ;; it is to accelerate or decelerate
0 K+ z# k' G$ _7 R) k! h V9 u phase ;; keeps track of the phase
- d w- [+ V3 G8 x( H9 c num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure1 E: l1 Q/ L a+ G% @6 }3 X
current-light ;; the currently selected light) {! h! O0 ^6 ~1 z- A$ r
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;; patch agentsets6 k' \* f4 a( w% p
intersections ;; agentset containing the patches that are intersections
: N0 g6 @% [3 Y- h# b1 ? roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle
* |5 V; B+ y5 V+ G. h. a up-car? ;; true if the turtle moves downwards and false if it moves to the right
- L) X! C# j- d1 j( k, o4 c6 i wait-time ;; the amount of time since the last time a turtle has moved/ V; P) r7 ~ a# w& w7 I
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patches-own
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9 i# m H+ w! E! a6 Y ^ intersection? ;; true if the patch is at the intersection of two roads
- R, f% L3 q0 |7 |- K1 |5 M. A# T green-light-up? ;; true if the green light is above the intersection. otherwise, false.1 K: Y6 x! t1 J1 d; v7 j5 }
;; false for a non-intersection patches.# _7 I# a7 h7 d# F
my-row ;; the row of the intersection counting from the upper left corner of the3 f) D- q) N9 C# q" M
;; world. -1 for non-intersection patches.
# R" }% H- W: U) t1 i7 U! n my-column ;; the column of the intersection counting from the upper left corner of the9 G; c6 E5 ^3 S* P
;; world. -1 for non-intersection patches.
: N) l' \( ~: C& `2 l# @' l my-phase ;; the phase for the intersection. -1 for non-intersection patches.
+ i% z$ s# ?' _7 ? auto? ;; whether or not this intersection will switch automatically.% p3 O- x l) O/ p1 F+ Y
;; false for non-intersection patches.
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7 {6 L9 ?8 o' \% \4 v* A; m, V;;;;;;;;;;;;;;;;;;;;;;% L; Q7 M! c' K" z. `+ S: E4 u
;; Setup Procedures ;;1 n2 W# d% C* `3 N, l
;;;;;;;;;;;;;;;;;;;;;;
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: l H ?. ?4 w9 G6 X6 h# n;; Initialize the display by giving the global and patch variables initial values.
' _& a: r7 W) S/ r;; Create num-cars of turtles if there are enough road patches for one turtle to
9 w+ p. u' k& f: v. o& R h;; be created per road patch. Set up the plots.
7 w/ x$ t8 N) s8 b' E0 Jto setup. V/ n. B6 o' J2 j. s: ^
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setup-globals
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+ C- B+ \7 j1 [3 r1 t' b# X, Z ;; First we ask the patches to draw themselves and set up a few variables
( N9 z+ B _: f% p7 u7 z setup-patches
' T% D8 U3 v7 P* E/ S make-current one-of intersections
# Y5 P I) a4 [( u( d label-current
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. y9 ^) b: g8 }: V% H8 o! v set-default-shape turtles "car"0 v7 L) I- G f" x5 r. g
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
$ I- b% S+ G" h" h6 P- @ "road. Either increase the amount of roads "
1 L0 @# n. L) Z5 b5 I( c "by increasing the GRID-SIZE-X or "( Y; g+ @2 b, a: [; P% P' g, U
"GRID-SIZE-Y sliders, or decrease the "
5 ^* i, ~9 n. f- U7 v "number of cars by lowering the NUMBER slider.\n"$ M0 L* Q0 g- w6 F
"The setup has stopped.")4 _9 x& U: n' c; P$ J/ L
stop
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8 ^# Z: q& V3 A( W2 f" Z ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
$ s( [0 L, X' }$ C; x crt num-cars
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3 h0 A8 i) g$ K8 ` setup-cars
& u8 `: A7 u$ ]7 \& A+ S set-car-color
( A1 Y& G' L* {+ {& p record-data
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;; give the turtles an initial speed* o- e O2 L' c& I3 L, b3 m7 o
ask turtles [ set-car-speed ]
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reset-ticks( i1 o3 e! w- S; |# G
end' h5 ?3 l2 E* d' |0 b a
4 [' h: y5 a8 S;; Initialize the global variables to appropriate values
) W8 b" t+ [6 E) Oto setup-globals2 K6 i: N$ T2 a: j; R
set current-light nobody ;; just for now, since there are no lights yet
0 C3 B% M6 T" S2 Q/ e set phase 0* s0 z( k9 ]& l9 |
set num-cars-stopped 0# p+ L M0 f; N% _ I/ G
set grid-x-inc world-width / grid-size-x
; j8 T% _0 @6 i3 z3 h$ E. l8 A- { 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
2 o3 C8 P# {) r' c: \6 g set acceleration 0.099
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" [5 g5 R% e5 N A) W) V;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
) F) P1 c4 b/ u2 j;; and initialize the traffic lights to one setting0 T! f x$ g. o6 n& P
to setup-patches
* s0 `/ u1 b b) ~" b! h ;; initialize the patch-owned variables and color the patches to a base-color) J7 R, F \# R" x! L$ u! p$ M( O
ask patches9 i: C- _" @9 L+ A
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% V1 b, E9 A0 O( w% Y @ set intersection? false$ F. r) D+ H: k5 q8 H- n3 j+ U
set auto? false/ Z3 `% k) q+ S9 V4 w- a1 X8 S
set green-light-up? true
' l% c h9 H, k0 [# F set my-row -1
3 P0 R* F$ P* E2 J" N6 N: s set my-column -1
4 X8 m5 ~. ^8 d7 ]2 x1 ~ set my-phase -13 x% o5 b& G- M% p' ]; b+ C5 X
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets5 ^+ K; ^. l/ H
set roads patches with4 I' A8 h7 d* ?# r2 g* M- O: p3 d
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ g) }6 d& B+ N. z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]. @0 I& G! _/ w: G( r5 d
set intersections roads with. x# O' ^; e4 I
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and3 r& ?# e" `* f7 r& D6 e
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]; @6 q% c% F, R* i! Z
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ask roads [ set pcolor white ]
5 L L; |0 `' S/ D setup-intersections% U* l2 L) R' H" k; J. {
end1 S5 I. u$ Y5 c
其中定义道路的句子,如下所示,是什么意思啊?" {* t, M0 {! k# F$ G& y
set roads patches with( _& f4 x5 } Y5 N2 X) f. [2 E
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
% B5 V$ [" s% l (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. j( R0 M0 o& B6 F7 {1 L9 D3 j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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