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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。
& @6 _: P# I3 s5 c! a7 X2 a( wnetlogo自带的social science--traffic grid这一例子当中,
- L0 j" a" O' r1 m! b3 v) X. }% Iglobals7 ^% P( a7 D7 c- v" y" y: W' W7 [# [
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, t. G3 x) m# z o4 M grid-x-inc ;; the amount of patches in between two roads in the x direction+ N; l& W; L4 n8 s
grid-y-inc ;; the amount of patches in between two roads in the y direction% Z4 L b* ]7 V
acceleration ;; the constant that controls how much a car speeds up or slows down by if
3 p1 f7 u- U- T2 J/ h& A& ? ;; it is to accelerate or decelerate
l: n- ~& L2 M phase ;; keeps track of the phase# U7 g. Z1 o$ Y- g2 k
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure# t, `* w- I8 }
current-light ;; the currently selected light
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;; patch agentsets& R3 J# j6 u" d/ Y
intersections ;; agentset containing the patches that are intersections4 c7 q' E! _9 T1 j; N$ F# O
roads ;; agentset containing the patches that are roads
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turtles-own
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/ H* G* q* S$ B( R j& [/ C, w speed ;; the speed of the turtle
7 {5 L X& W: i2 X; K9 V up-car? ;; true if the turtle moves downwards and false if it moves to the right
* ]2 i2 U/ [9 w2 N. {" T5 F$ ^ wait-time ;; the amount of time since the last time a turtle has moved3 G0 t. P, G' O2 H( L
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1 {% D0 S1 q xpatches-own
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; ^# Z% h9 o, n% u1 }$ m intersection? ;; true if the patch is at the intersection of two roads- @- M- u$ k# Z
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
- k# d. t: ?! l. d$ L ;; false for a non-intersection patches.
# H1 r w! F/ s, b9 e8 n my-row ;; the row of the intersection counting from the upper left corner of the
( Z% l0 F% r& a _7 [( | ;; world. -1 for non-intersection patches.
c; ?7 A! \# \; u# q! n# q my-column ;; the column of the intersection counting from the upper left corner of the( X& B. Y, `: v* |4 w
;; world. -1 for non-intersection patches.
. Z6 W! V s& D D+ F# N. F my-phase ;; the phase for the intersection. -1 for non-intersection patches.9 N" J% V2 l: u+ |6 b
auto? ;; whether or not this intersection will switch automatically.4 r$ t, b/ y0 c0 E; I. F
;; false for non-intersection patches.; H' U9 I5 q$ P% o% s# X
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;;;;;;;;;;;;;;;;;;;;;;
4 J. e8 K. I6 N; t! Y;; Setup Procedures ;;9 v% D! n9 }# a0 D4 D8 }
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.- n4 f7 Y% G8 H/ B( ?
;; Create num-cars of turtles if there are enough road patches for one turtle to8 E2 f9 R8 T/ |8 o1 W% W+ D5 z
;; be created per road patch. Set up the plots.6 t$ b4 ]; q& T; N8 J3 ^
to setup7 |! a% x# O: f N5 z
ca
K3 I7 E: w8 ]8 j( G setup-globals2 L% ^2 m) G3 G) t) p! g
* O8 p- ]2 f1 |1 u& c' u0 P ;; First we ask the patches to draw themselves and set up a few variables
9 y6 } U3 W% t, {! q' X; T setup-patches8 |' K- ~* F9 h
make-current one-of intersections, j% D2 _7 z U, N* C: f9 E
label-current/ [8 L; ~5 D( O! A( H4 g: c3 C
3 N# ?4 m& e7 m; f set-default-shape turtles "car"
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if (num-cars > count roads)
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: \. G$ o, w8 F7 x( @2 ] user-message (word "There are too many cars for the amount of "- y! J% u# W0 m* ]
"road. Either increase the amount of roads "
( u- u3 \+ ~+ o$ ` "by increasing the GRID-SIZE-X or " c# q# j, p& Y# X/ F* o
"GRID-SIZE-Y sliders, or decrease the "2 ?- }+ b$ B5 |7 E* d
"number of cars by lowering the NUMBER slider.\n"+ j/ G) _. |+ G; J, k$ f8 ?
"The setup has stopped.")
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color+ Y5 B8 u( a/ u: |5 F
crt num-cars" ?& R0 U8 D$ P& a) g
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setup-cars6 L" [3 h0 g. G |
set-car-color
& t' l1 {* \- |9 V* E: }+ x record-data) }6 M, e4 ]0 A2 g
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+ Y8 g# J+ P8 ?, A* k( {: e ;; give the turtles an initial speed
! x3 v" H4 x1 w4 i2 X9 w5 u ask turtles [ set-car-speed ]2 n8 c- E: `2 F" [/ k
: t K, b* f- S8 v" y0 j" y2 Q reset-ticks
+ X+ X7 {7 _, Aend
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; J$ K+ q* u8 r" I- a;; Initialize the global variables to appropriate values
1 I* T2 e6 L* e% p$ k* V. V" Gto setup-globals) b Q+ n2 R" g* \4 D J+ V
set current-light nobody ;; just for now, since there are no lights yet" A0 Y# N+ F- o2 X
set phase 02 B" Q T7 n- {; X# {
set num-cars-stopped 0! Y" e; h* L5 z/ x3 d0 d
set grid-x-inc world-width / grid-size-x# D. {7 W& t6 H1 w r
set grid-y-inc world-height / grid-size-y U$ }0 [. A. j* m9 |+ ?, x
( Y* I k, i8 ]! r: E5 A q. n ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
! J/ i; d. o: o7 q8 o* m8 Q" _ set acceleration 0.099; D! X- [7 l( ` X$ G: [8 G4 H
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,* S8 T# B. u2 x3 p" S+ m3 d
;; and initialize the traffic lights to one setting0 M% j" k: d7 O0 r8 S- O2 T8 |- d# y
to setup-patches* |% p7 ]- p2 k) E
;; initialize the patch-owned variables and color the patches to a base-color
4 c+ o- |4 U4 n. h O4 h ask patches
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# @4 [# ]# ~ y2 u/ {$ m set intersection? false
5 Z) j* X; r; {% _; X) | set auto? false
+ U2 c! H! ]/ Z/ Q6 A7 V set green-light-up? true
2 x2 |' ?( f; w4 N1 e; z/ b, p set my-row -1
& }. n7 W; J8 q- D2 I; V0 b set my-column -1
9 W4 _0 d7 Z2 g: f0 k: V set my-phase -1
* {+ L/ ?( L& G6 |) e9 Z set pcolor brown + 3. `9 C1 Q) a3 A4 c' h! n3 {
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;; initialize the global variables that hold patch agentsets" S6 L$ Y, U8 p. b
set roads patches with6 R! j1 K: a8 b: U
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: a4 X, [7 T* |4 z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]. U, ~' S/ S6 q* Y+ S6 p1 o( `
set intersections roads with0 w, \ V6 |# [
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
0 ^' n" S8 t3 ]3 Y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 _ i: U: p1 l. g8 [1 t
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ask roads [ set pcolor white ]
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. A8 h$ i, G& i5 d2 |8 @" n M8 _其中定义道路的句子,如下所示,是什么意思啊?
+ s" Y7 Z& w) T* E. n) H set roads patches with
, C+ o+ S( p' I+ X" e% U& U( m0 V. } [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 c# z5 `( j) A. c) F: W9 x8 @ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ k) g( G4 w: ?8 Q% z/ m* |; u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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