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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。, [. a$ h8 }% h% J1 {* X5 @. v5 k
netlogo自带的social science--traffic grid这一例子当中,; A" V4 a( N- [9 Z) e# j
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction7 k8 E0 `6 l- ~
grid-y-inc ;; the amount of patches in between two roads in the y direction
M* l' m) }4 k0 d) X8 D0 @* m: h acceleration ;; the constant that controls how much a car speeds up or slows down by if
5 C( J/ f* \. l7 B ;; it is to accelerate or decelerate ]0 E9 T5 F& |
phase ;; keeps track of the phase
" {4 l" `3 V5 x0 r) ^6 k! S num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
g/ ~2 c8 c9 H7 c; z current-light ;; the currently selected light
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;; patch agentsets% l1 Y# H8 f# U- |3 A* }& y
intersections ;; agentset containing the patches that are intersections
% ~/ e6 C" u1 m" m3 V q( v roads ;; agentset containing the patches that are roads/ k; i4 P9 U8 u/ p4 w8 D. L
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0 }. j; ]$ n# k$ s, ]turtles-own
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# l: i( Q& E. E6 m speed ;; the speed of the turtle
$ Y' T& {. y0 r+ {! y up-car? ;; true if the turtle moves downwards and false if it moves to the right
# J8 L: q/ R0 [6 |/ E2 E0 ~* Z wait-time ;; the amount of time since the last time a turtle has moved
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patches-own1 X( O" G$ w/ i
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intersection? ;; true if the patch is at the intersection of two roads. `0 t$ A+ K& p9 f h" w5 [/ g- w
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
: E. o, k+ I+ z ;; false for a non-intersection patches.0 S% v9 n1 a) X; j3 P8 K) H3 z' ^
my-row ;; the row of the intersection counting from the upper left corner of the
9 A3 a, l. E, \5 o' q, ]* E ;; world. -1 for non-intersection patches.& S7 l( }- B1 U1 b
my-column ;; the column of the intersection counting from the upper left corner of the5 X9 |5 a# ]% H& U/ b
;; world. -1 for non-intersection patches.2 e |) h0 {0 X+ Z( m4 t w8 H
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
9 V7 l; m. }) T J1 U" @6 t4 O1 K8 m auto? ;; whether or not this intersection will switch automatically.
' \7 y/ j6 U) ^6 h$ O' G8 d# v ;; false for non-intersection patches.% z7 C9 c) m+ I+ a; o3 I' \( D# D2 t
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;;;;;;;;;;;;;;;;;;;;;;+ V! n* L' g( A; H0 I2 k! ]* B
;; Setup Procedures ;;, I' g4 k: C7 e2 N3 y
;;;;;;;;;;;;;;;;;;;;;;6 i+ n9 M+ w) |% B, y$ L
3 D) a2 }/ p- R) W9 I2 _6 V;; Initialize the display by giving the global and patch variables initial values.& I. x3 _& P0 Y' M( C' q/ Q
;; Create num-cars of turtles if there are enough road patches for one turtle to
\" o/ B0 e! Y7 L;; be created per road patch. Set up the plots.( v3 C7 E$ t W# C
to setup6 z' V) v8 ^' K/ m9 ?2 [* j
ca
8 V# x. |8 j. m; G7 Y setup-globals
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$ z# b9 u5 _% G. N' P) g L ;; First we ask the patches to draw themselves and set up a few variables
9 W! g Z7 m/ k% O) U# _! S( r setup-patches
~6 M8 M t) a& a8 x/ y make-current one-of intersections2 L5 G$ U# o6 e8 ]: A$ l
label-current- c. {- Z6 ?& G% i
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set-default-shape turtles "car"7 _+ G7 }, d. P1 U
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if (num-cars > count roads)
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+ w) g1 y( @. [' q user-message (word "There are too many cars for the amount of "
. ~) n( K& q. Q# M2 s "road. Either increase the amount of roads "& D. H" u7 A% G! f
"by increasing the GRID-SIZE-X or "' d6 P J+ `5 ?, u
"GRID-SIZE-Y sliders, or decrease the "! U1 g% t" O) W9 w$ @
"number of cars by lowering the NUMBER slider.\n"
! }# s$ I4 i) ?& u+ f$ o "The setup has stopped."), F1 s. J! f/ A: T$ ~9 K4 v
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color! F6 N* [& r, f2 q C! x+ S- g; O
crt num-cars1 s# G' d2 U. C2 S, m8 w0 @, n
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setup-cars7 K+ M& O" \1 C
set-car-color5 q* [9 ~/ i2 X
record-data& m. E. T% X) f5 j, Y( X
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: Q9 E1 w+ [& m7 V- o4 ^ ;; give the turtles an initial speed
5 c, M* Y* W& i' g3 v" u5 Z9 o ask turtles [ set-car-speed ]
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& x& R2 F1 i3 X reset-ticks8 D$ ~) l9 T; F
end
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
5 H, i/ U( e# ?, _/ U8 w6 y set phase 0
5 J2 g4 F) t; ]$ H6 D set num-cars-stopped 01 W7 z& u5 k- H& P+ G
set grid-x-inc world-width / grid-size-x
7 M- B4 |6 _3 U; K2 | set grid-y-inc world-height / grid-size-y
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: z0 l3 j# \/ P: n3 h; i ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary2 G; N) y2 o8 R+ w# |- U8 Q/ Z
set acceleration 0.099
& ^8 Y* D' j) ~% s5 ?end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,. ? a( L# F% q. p. B9 Y
;; and initialize the traffic lights to one setting
) l- m. D: K! D. }+ P' n6 fto setup-patches- _% V5 ]( W; w) w* l, v# |
;; initialize the patch-owned variables and color the patches to a base-color$ Y9 W, U: x. C. p0 f& _* s
ask patches
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set intersection? false
/ g$ F6 @ R% W4 d set auto? false9 q; ?9 G9 I; {4 J' y& C
set green-light-up? true8 J+ o: Q( F; t5 ]9 ~. q
set my-row -1
- @ G/ f7 W6 D. y% t set my-column -1# c4 o7 u: J5 Y+ x0 H, O' r
set my-phase -1
K) X! x u! ~% r' @9 E1 N! J set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
( `- T1 Y8 Z, q% _! ^ set roads patches with' k" z, z* ^8 v0 B @( B. U
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, R' t3 R% X- X% \- ~. z+ z/ F: ]1 L2 y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 ?& W8 M, c6 z9 b7 d set intersections roads with
9 K! E V3 {9 t3 m [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
0 y5 X& f- y1 ]4 K0 q- [# b (floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 D, a* k7 G p
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ask roads [ set pcolor white ]
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+ @- C2 o3 k( A) p, Jend: K8 W0 ?$ i! |
其中定义道路的句子,如下所示,是什么意思啊?
" }$ B( T2 `% s' _' T! F& G set roads patches with
! v# [4 d G/ K1 [/ T: g! V [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
9 B+ X) c8 @; t2 Z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ K& M0 L+ Y/ P- I# E5 @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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